From 896ecda5fbc4c934a5a1ec928ba0cc3355750c45 Mon Sep 17 00:00:00 2001
From: Rain <rain@oxide.computer>
Date: Fri, 6 Feb 2026 03:27:17 +0000
Subject: [PATCH] [spr] changes to main this commit is based on

Created using spr 1.3.6-beta.1

[skip ci]
---
 src/change.rs                                 |  68 +-
 src/compare.rs                                |  65 +-
 src/context.rs                                |  42 +-
 src/lib.rs                                    |  71 +-
 src/operations.rs                             |  30 +-
 src/path.rs                                   | 620 ++++++++++++++++++
 src/resolve.rs                                |   5 +-
 src/schema.rs                                 |  22 +-
 .../simple/output/add-cookie-parameter.out    |  28 +-
 .../simple/output/add-default-response.out    |  28 +-
 .../simple/output/add-header-parameter.out    |  28 +-
 .../simple/output/add-operation-with-id.out   |  28 +-
 tests/cases/simple/output/add-operation.out   |  28 +-
 .../cases/simple/output/add-optional-body.out |  28 +-
 .../simple/output/add-optional-parameter.out  |  28 +-
 .../cases/simple/output/add-required-body.out |  28 +-
 .../simple/output/add-required-parameter.out  |  28 +-
 .../cases/simple/output/add-response-code.out |  28 +-
 .../simple/output/add-type-extension.out      |  32 +-
 tests/cases/simple/output/allof-to-anyof.out  |  32 +-
 .../allof-to-oneof-with-type-change.out       |  68 +-
 tests/cases/simple/output/allof-to-oneof.out  |  32 +-
 .../output/allof-to-ref-with-type-change.out  |  68 +-
 tests/cases/simple/output/allof-to-ref.out    |  32 +-
 .../cases/simple/output/any-schema-change.out |  32 +-
 tests/cases/simple/output/anyof-to-allof.out  |  32 +-
 tests/cases/simple/output/anyof-to-oneof.out  |  32 +-
 tests/cases/simple/output/anyof-to-ref.out    |  32 +-
 tests/cases/simple/output/array-items-add.out |  32 +-
 .../simple/output/array-items-remove.out      |  34 +-
 .../simple/output/array-max-items-change.out  |  32 +-
 .../simple/output/array-min-items-change.out  |  32 +-
 .../output/array-unique-items-change.out      |  32 +-
 .../simple/output/body-description-change.out |  28 +-
 .../simple/output/body-extension-change.out   |  28 +-
 .../output/body-optional-to-required.out      |  28 +-
 .../output/body-required-to-optional.out      |  28 +-
 tests/cases/simple/output/boolean-change.out  |  32 +-
 .../simple/output/boolean-enum-change.out     |  32 +-
 .../simple/output/change-default-response.out |   2 +-
 .../simple/output/change-header-parameter.out |  28 +-
 ...change-operation-parameter-requirement.out |  28 +-
 .../change-operation-parameter-type.out       |  28 +-
 .../simple/output/change-property-type.out    |  32 +-
 tests/cases/simple/output/inline-to-allof.out |  28 +-
 .../simple/output/integer-format-change.out   |  32 +-
 .../cases/simple/output/modify-cycle-type.out |  34 +-
 .../output/multi-allof-variant-change.out     |  32 +-
 .../output/multi-anyof-variant-change.out     |  32 +-
 .../output/multi-oneof-count-change.out       |  32 +-
 .../output/multi-oneof-variant-change.out     |  32 +-
 .../simple/output/not-inner-to-allof.out      |  32 +-
 tests/cases/simple/output/not-to-allof.out    |  32 +-
 .../output/number-constraints-change.out      |  32 +-
 .../output/object-additional-props-false.out  |  32 +-
 .../object-additional-props-schema-change.out |  32 +-
 .../object-additional-props-type-change.out   |  32 +-
 .../output/object-max-properties-change.out   |  32 +-
 .../output/object-min-properties-change.out   |  32 +-
 tests/cases/simple/output/oneof-to-allof.out  |  32 +-
 tests/cases/simple/output/oneof-to-anyof.out  |  32 +-
 tests/cases/simple/output/oneof-to-ref.out    |  32 +-
 .../output/param-required-to-optional.out     |  28 +-
 .../simple/output/param-schema-to-content.out |  28 +-
 .../cases/simple/output/ref-chain-change.out  |  78 ++-
 tests/cases/simple/output/ref-to-allof.out    |  32 +-
 tests/cases/simple/output/ref-to-anyof.out    |  32 +-
 .../simple/output/ref-to-inline-allof.out     |  64 +-
 tests/cases/simple/output/ref-to-oneof.out    |  32 +-
 .../simple/output/remove-default-response.out |  28 +-
 .../simple/output/remove-header-parameter.out |  28 +-
 .../output/remove-operation-parameter.out     |  28 +-
 .../cases/simple/output/remove-operation.out  |  28 +-
 .../simple/output/remove-optional-body.out    |  28 +-
 .../simple/output/remove-required-body.out    |  28 +-
 .../simple/output/remove-response-code.out    |  28 +-
 .../output/remove-unnamed-operation.out       |  28 +-
 .../output/schema-kind-type-to-oneof.out      |  36 +-
 .../simple/output/string-format-change.out    |  32 +-
 .../cases/simple/output/type-indirection.out  |  36 +-
 tests/cases/simple/output/type-rename.out     |   4 +-
 .../simple/output/unhandled-add-prop.out      |  64 +-
 .../wrapper-unchanged-with-type-change.out    |  36 +-
 tests/test_changes.rs                         |  32 +-
 84 files changed, 2422 insertions(+), 961 deletions(-)
 create mode 100644 src/path.rs

diff --git a/src/change.rs b/src/change.rs
index e29b3cf..d8b0974 100644
--- a/src/change.rs
+++ b/src/change.rs
@@ -1,9 +1,10 @@
-// Copyright 2025 Oxide Computer Company
+// Copyright 2026 Oxide Computer Company
+
+use std::fmt;
 
 use crate::JsonPathStack;
 
 // Describes any change detected between two OpenAPI documents.
-#[derive(Debug)]
 pub struct Change {
     /// Human-readable message describing the nature of the change.
     pub message: String,
@@ -18,10 +19,71 @@ pub struct Change {
     /// Classification of the change compatibility.
     pub class: ChangeClass,
 
-    /// Details on the kind of change
+    /// Details on the kind of change.
     pub details: ChangeDetails,
 }
 
+// Format `Change` in the nested `paths`/`changes` layout that will be
+// introduced when the type is restructured into `Change`, `ChangePath`, and
+// `ChangeInfo`. Doing this ahead of time keeps the restructuring commit free
+// of test-output noise.
+impl fmt::Debug for Change {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        /// Wrapper that formats as `ChangePath { old, new, comparison }`.
+        struct PathFmt<'a> {
+            old: &'a JsonPathStack,
+            new: &'a JsonPathStack,
+            comparison: &'a ChangeComparison,
+        }
+
+        impl fmt::Debug for PathFmt<'_> {
+            fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+                f.debug_struct("ChangePath")
+                    .field("old", self.old)
+                    .field("new", self.new)
+                    .field("comparison", self.comparison)
+                    .finish()
+            }
+        }
+
+        /// Wrapper that formats as `ChangeInfo { old_subpath, new_subpath,
+        /// message, class, details }`.
+        struct InfoFmt<'a> {
+            message: &'a str,
+            class: &'a ChangeClass,
+            details: &'a ChangeDetails,
+        }
+
+        impl fmt::Debug for InfoFmt<'_> {
+            fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+                f.debug_struct("ChangeInfo")
+                    .field("old_subpath", &"")
+                    .field("new_subpath", &"")
+                    .field("message", &self.message)
+                    .field("class", self.class)
+                    .field("details", self.details)
+                    .finish()
+            }
+        }
+
+        let path = PathFmt {
+            old: &self.old_path,
+            new: &self.new_path,
+            comparison: &self.comparison,
+        };
+        let info = InfoFmt {
+            message: &self.message,
+            class: &self.class,
+            details: &self.details,
+        };
+
+        f.debug_struct("Change")
+            .field("paths", &[path])
+            .field("changes", &[info])
+            .finish()
+    }
+}
+
 impl Change {
     pub fn new(
         message: impl ToString,
diff --git a/src/compare.rs b/src/compare.rs
index eb77743..a296768 100644
--- a/src/compare.rs
+++ b/src/compare.rs
@@ -1,7 +1,8 @@
-// Copyright 2025 Oxide Computer Company
+// Copyright 2026 Oxide Computer Company
 
 use std::collections::BTreeMap;
 
+use anyhow::Context as _;
 use indexmap::IndexMap;
 use openapiv3::{
     MediaType, Operation, Parameter, ParameterSchemaOrContent, ReferenceOr, RequestBody,
@@ -9,7 +10,7 @@ use openapiv3::{
 use serde_json::Value;
 
 use crate::{
-    Change, ChangeClass, ChangeComparison, ChangeDetails,
+    Change, ChangeClass, ChangeComparison, ChangeDetails, JsonPathStack,
     context::{Context, Contextual, ToContext},
     operations::{all_params, operations},
     resolve::ReferenceOrResolver,
@@ -24,21 +25,58 @@ pub fn compare(old: &Value, new: &Value) -> anyhow::Result<Vec<Change>> {
     Ok(comp.changes)
 }
 
+/// The full current location in a document, including appended segments.
+///
+/// This is the path returned by `JsonPathStack::current_pointer()`, wrapped
+/// in a newtype to prevent confusion with other path-like strings (e.g. a
+/// future base path type that excludes appended segments).
+#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
+pub(crate) struct CurrentPointer(String);
+
+impl CurrentPointer {
+    pub(crate) fn new(stack: &JsonPathStack) -> Self {
+        Self(stack.current_pointer().to_string())
+    }
+}
+
+/// Key for memoizing schema comparison results.
+///
+/// This uses the full schema path (including internal paths like
+/// `SubType/properties/value`) for accurate memoization. The comparison
+/// direction (Input vs Output) is included because compatibility semantics
+/// differ based on direction.
+#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord)]
+pub(crate) struct VisitedKey {
+    comparison: SchemaComparison,
+    old_path: CurrentPointer,
+    new_path: CurrentPointer,
+}
+
+impl VisitedKey {
+    pub(crate) fn new(
+        comparison: SchemaComparison,
+        old_stack: &JsonPathStack,
+        new_stack: &JsonPathStack,
+    ) -> Self {
+        Self {
+            comparison,
+            old_path: CurrentPointer::new(old_stack),
+            new_path: CurrentPointer::new(new_stack),
+        }
+    }
+}
+
 #[derive(Default)]
 pub(crate) struct Compare {
     pub changes: Vec<Change>,
-    /// Cache comparisons (type of comparison, old and new path to the schema)
-    /// and the boolean result (are the schemas backward-compatible?).
-    pub visited: BTreeMap<(SchemaComparison, String, String), bool>,
+    /// Memoization of schema comparison results, keyed by full path pair.
+    pub visited: BTreeMap<VisitedKey, bool>,
 }
 
 impl Compare {
     pub fn compare(&mut self, old: &Value, new: &Value) -> anyhow::Result<()> {
-        let old_context = Context::new(old);
-        let old_operations = operations(&old_context)?;
-
-        let new_context = Context::new(new);
-        let new_operations = operations(&new_context)?;
+        let old_operations = operations(old).context("error deserializing old OpenAPI document")?;
+        let new_operations = operations(new).context("error deserializing new OpenAPI document")?;
 
         let SetCompare {
             a_unique,
@@ -52,10 +90,11 @@ impl Compare {
                 Some(name) => name.as_str(),
                 None => "<unnamed>",
             };
+            let new_paths_root = Context::for_paths_root(new);
             self.push_change(
                 format!("The operation {op_name} was removed"),
                 &op_info.operation,
-                &new_context.append("paths"),
+                &new_paths_root,
                 ChangeComparison::Structural,
                 ChangeClass::BackwardIncompatible,
                 ChangeDetails::Removed,
@@ -68,10 +107,10 @@ impl Compare {
                 Some(name) => name.as_str(),
                 None => "<unnamed>",
             };
-
+            let old_paths_root = Context::for_paths_root(old);
             self.push_change(
                 format!("The operation {op_name} was added"),
-                &old_context.append("paths"),
+                &old_paths_root,
                 &op_info.operation,
                 ChangeComparison::Structural,
                 ChangeClass::ForwardIncompatible,
diff --git a/src/context.rs b/src/context.rs
index 04c6c7e..80b6830 100644
--- a/src/context.rs
+++ b/src/context.rs
@@ -1,4 +1,4 @@
-// Copyright 2025 Oxide Computer Company
+// Copyright 2026 Oxide Computer Company
 
 use std::{borrow::Cow, ops::Deref};
 
@@ -6,7 +6,10 @@ use openapiv3::ReferenceOr;
 use serde::de::DeserializeOwned;
 use serde_json::Value;
 
-use crate::{JsonPathStack, resolve::ReferenceOrResolver};
+use crate::{
+    path::{EndpointPath, InvalidComponentRef, JsonPathStack},
+    resolve::ReferenceOrResolver,
+};
 
 #[derive(Clone, Debug)]
 pub struct Context<'a> {
@@ -15,33 +18,42 @@ pub struct Context<'a> {
 }
 
 impl<'a> Context<'a> {
-    pub fn new(raw_openapi: &'a Value) -> Self {
+    /// Create a context at a specific endpoint.
+    ///
+    /// This is the normal way to create a context for schema comparison.
+    pub fn for_endpoint(raw_openapi: &'a Value, endpoint: EndpointPath) -> Self {
         Self {
             raw_openapi,
-            stack: JsonPathStack::new(),
+            stack: JsonPathStack::for_endpoint(endpoint),
         }
     }
 
-    pub fn append(&self, segment: &str) -> Context<'a> {
-        let stack = self
-            .stack
-            .append(&segment.replace("~", "~0").replace("/", "~1"));
-
+    /// Create a context at `#/paths`.
+    ///
+    /// This is used only when reporting that an operation was added or removed,
+    /// where one side doesn't have the operation. In normal use, prefer
+    /// `for_endpoint()`.
+    pub fn for_paths_root(raw_openapi: &'a Value) -> Self {
         Self {
-            raw_openapi: self.raw_openapi,
-            stack,
+            raw_openapi,
+            stack: JsonPathStack::paths_root(),
         }
     }
 
-    pub(crate) fn push(&self, path: &str) -> Context<'a> {
-        let stack = self.stack.push(path);
-
+    pub fn append(&self, segment: &str) -> Context<'a> {
         Self {
             raw_openapi: self.raw_openapi,
-            stack,
+            stack: self.stack.append(segment),
         }
     }
 
+    pub(crate) fn push(&self, path: &str) -> Result<Context<'a>, InvalidComponentRef> {
+        Ok(Self {
+            raw_openapi: self.raw_openapi,
+            stack: self.stack.push(path)?,
+        })
+    }
+
     pub fn stack(&self) -> &JsonPathStack {
         &self.stack
     }
diff --git a/src/lib.rs b/src/lib.rs
index dbdbe3a..ac548b6 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,4 +1,4 @@
-// Copyright 2025 Oxide Computer Company
+// Copyright 2026 Oxide Computer Company
 
 //! Drift
 //!
@@ -8,76 +8,11 @@ mod change;
 mod compare;
 mod context;
 mod operations;
+mod path;
 mod resolve;
 mod schema;
 mod setops;
 
-use std::fmt::Debug;
-
 pub use change::*;
 pub use compare::compare;
-
-/// Represents a location in an OpenAPI document.
-///
-/// This takes the the form of a stack of JSON paths where each element of the
-/// stack starts at the document root and terminates in either a reference
-/// (i.e. to the subsequent element in the stack) or the item being identified.
-#[derive(Clone)]
-pub struct JsonPathStack {
-    top: String,
-    stack: Vec<String>,
-}
-
-impl Debug for JsonPathStack {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        let mut out = f.debug_list();
-        out.entry(&self.top);
-        self.stack.iter().rev().for_each(|path| {
-            let _ = out.entry(path);
-        });
-        out.finish()
-    }
-}
-
-impl JsonPathStack {
-    fn new() -> Self {
-        Self {
-            top: "#".to_string(),
-            stack: Vec::new(),
-        }
-    }
-
-    fn append(&self, segment: &str) -> JsonPathStack {
-        let Self { top, stack } = self;
-
-        Self {
-            top: format!("{top}/{segment}"),
-            stack: stack.clone(),
-        }
-    }
-
-    fn push(&self, path: &str) -> JsonPathStack {
-        let Self { top, stack } = self;
-        let mut stack = stack.clone();
-        stack.push(format!("{top}/$ref"));
-
-        Self {
-            top: path.to_string(),
-            stack,
-        }
-    }
-
-    pub fn contains_cycle(&self) -> bool {
-        self.stack.iter().any(|item| item.starts_with(&self.top))
-    }
-
-    pub fn iter(&self) -> impl Iterator<Item = &String> {
-        std::iter::once(&self.top).chain(self.stack.iter().rev())
-    }
-}
-
-impl Default for JsonPathStack {
-    fn default() -> Self {
-        Self::new()
-    }
-}
+pub use path::JsonPathStack;
diff --git a/src/operations.rs b/src/operations.rs
index 700cd44..3874cb6 100644
--- a/src/operations.rs
+++ b/src/operations.rs
@@ -1,4 +1,4 @@
-// Copyright 2025 Oxide Computer Company
+// Copyright 2026 Oxide Computer Company
 
 use std::{collections::BTreeMap, sync::LazyLock};
 
@@ -7,8 +7,11 @@ use openapiv3::{OpenAPI, Operation, Parameter, ParameterData, ReferenceOr};
 use regex::Regex;
 use serde::Deserialize;
 
+use serde_json::Value;
+
 use crate::{
     context::{Context, Contextual},
+    path::EndpointPath,
     resolve::ReferenceOrResolver,
 };
 
@@ -38,24 +41,27 @@ pub struct OperationInfo<'a> {
     pub shared_parameters: Contextual<'a, Vec<ReferenceOr<Parameter>>>,
 }
 
-pub fn operations<'a>(
-    context: &Context<'a>,
-) -> anyhow::Result<Vec<(OperationKey, OperationInfo<'a>)>> {
-    let api = OpenAPI::deserialize(context.raw_openapi).unwrap();
+pub fn operations(raw_openapi: &Value) -> anyhow::Result<Vec<(OperationKey, OperationInfo<'_>)>> {
+    let api = OpenAPI::deserialize(raw_openapi)?;
 
     let mut out = Vec::new();
 
-    let context = context.append("paths");
-
     for (path, ref_or_operation) in api.paths.paths.iter() {
-        let context = context.append(path);
-        let (path_item, context) = ref_or_operation.resolve(&context)?;
+        // Build a context at #/paths/<path> for resolving path item refs.
+        let path_endpoint = EndpointPath::for_path(path);
+        let path_context = Context::for_endpoint(raw_openapi, path_endpoint);
+        let (path_item, path_context) = ref_or_operation.resolve(&path_context)?;
 
-        let shared_parameters =
-            Contextual::new(context.append("parameters"), path_item.parameters.clone());
+        let shared_parameters = Contextual::new(
+            path_context.append("parameters"),
+            path_item.parameters.clone(),
+        );
 
         for (method, operation) in path_item.iter() {
-            let context = context.append(method);
+            // Build endpoint path for this operation: #/paths/<path>/<method>
+            let endpoint = EndpointPath::for_path(path).append(method);
+            let context = Context::for_endpoint(raw_openapi, endpoint);
+
             let op_key = OperationKey::new(path, method);
             let op_info = OperationInfo {
                 path: path.clone(),
diff --git a/src/path.rs b/src/path.rs
new file mode 100644
index 0000000..6df11a5
--- /dev/null
+++ b/src/path.rs
@@ -0,0 +1,620 @@
+// Copyright 2026 Oxide Computer Company
+
+//! Strongly-typed JSON path stack for tracking location in OpenAPI documents.
+//!
+//! This module provides types for tracking location while traversing an OpenAPI
+//! document, particularly when following `$ref` references.
+//!
+//! ## State machine
+//!
+//! The [`JsonPathStack`] uses an internal state machine ([`PathState`]) that
+//! enforces these invariants at the type level:
+//!
+//! - **`PathsRoot`**: At `#/paths`, used only for reporting operation add/remove.
+//!   Cannot follow refs or append segments from this state.
+//! - **`AtEndpoint`**: At an endpoint path (`#/paths/<path>/...`), no refs
+//!   followed yet. Can append segments or push a ref.
+//! - **`AtComponent`**: At a ref target (any JSON pointer), with a reference
+//!   chain. The chain always has exactly one endpoint origin (the first ref),
+//!   followed by zero or more intermediates.
+//!
+//! This makes illegal states unrepresentable: you cannot have endpoint refs
+//! mixed into the intermediate chain, or push refs from `PathsRoot`.
+
+use std::fmt;
+
+/// Error returned when `JsonPathStack::push()` receives an invalid reference.
+///
+/// A valid reference must be a JSON pointer starting with `#/`.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub(crate) struct InvalidComponentRef {
+    /// The invalid reference that was provided.
+    pub(crate) reference: String,
+}
+
+impl fmt::Display for InvalidComponentRef {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(
+            f,
+            "invalid reference {:?}: expected JSON pointer starting with #/",
+            self.reference
+        )
+    }
+}
+
+impl std::error::Error for InvalidComponentRef {}
+
+/// An endpoint path, guaranteed to start with `#/paths/`.
+///
+/// This represents a location within the paths section of an OpenAPI document.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub(crate) struct EndpointPath(String);
+
+impl EndpointPath {
+    /// Create an endpoint path from a raw API path (like `/users/{id}`).
+    ///
+    /// This escapes the path according to JSON pointer rules (RFC 6901).
+    pub(crate) fn for_path(api_path: &str) -> Self {
+        let escaped = escape_json_pointer_segment(api_path);
+        Self(format!("#/paths/{}", escaped))
+    }
+
+    /// Append a path segment, escaping special characters per RFC 6901.
+    pub(crate) fn append(&self, segment: &str) -> Self {
+        let escaped = escape_json_pointer_segment(segment);
+        Self(format!("{}/{}", self.0, escaped))
+    }
+
+    /// Get the JSON pointer string.
+    fn as_str(&self) -> &str {
+        &self.0
+    }
+}
+
+/// A JSON pointer reference (starting with `#/`): guaranteed by construction.
+///
+/// This represents a location after following at least one `$ref`. It can point
+/// to any location in the document, not only components.
+#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+struct RefTargetPath(String);
+
+impl RefTargetPath {
+    /// Parse from a JSON pointer. Returns `None` if not a valid local ref.
+    fn parse(pointer: &str) -> Option<Self> {
+        pointer.starts_with("#/").then(|| Self(pointer.to_string()))
+    }
+
+    /// Append a path segment, escaping special characters per RFC 6901.
+    fn append(&self, segment: &str) -> Self {
+        let escaped = escape_json_pointer_segment(segment);
+        Self(format!("{}/{}", self.0, escaped))
+    }
+
+    /// Get the JSON pointer string.
+    fn as_str(&self) -> &str {
+        &self.0
+    }
+}
+
+/// The state of the path stack, encoding the invariants:
+///
+/// - If refs have been followed, the first was always from an endpoint.
+/// - All subsequent refs form a chain of intermediate locations.
+/// - Transitions: endpoint → ref target, or ref target → ref target.
+#[derive(Clone, Debug, PartialEq, Eq)]
+enum PathState {
+    /// At the paths root (`#/paths`), used only for operation add/remove reporting.
+    /// Cannot follow refs from this state.
+    PathsRoot,
+
+    /// At an endpoint, no refs followed yet.
+    AtEndpoint(EndpointPath),
+
+    /// At a component, with reference chain.
+    AtComponent {
+        /// The current component location.
+        current: RefTargetPath,
+        /// Where the first ref was followed from (always an endpoint, with
+        /// `/$ref` appended).
+        origin_ref: EndpointPath,
+        /// Intermediate refs (all from components, each with `/$ref` appended).
+        intermediate_refs: Vec<RefTargetPath>,
+    },
+}
+
+/// Strongly-typed path stack for tracking location in OpenAPI documents.
+///
+/// The stack tracks the location while traversing an OpenAPI document,
+/// particularly when following `$ref` references.
+#[derive(Clone)]
+pub struct JsonPathStack {
+    state: PathState,
+}
+
+impl JsonPathStack {
+    /// Create a path stack starting at the given endpoint.
+    ///
+    /// The endpoint must be a valid endpoint path (starting with `#/paths/`).
+    pub(crate) fn for_endpoint(endpoint: EndpointPath) -> Self {
+        Self {
+            state: PathState::AtEndpoint(endpoint),
+        }
+    }
+
+    /// Create a path stack at `#/paths` (no specific endpoint).
+    ///
+    /// This is used only when reporting that an operation was added or removed,
+    /// where one side doesn't have the operation at all. In normal use, prefer
+    /// `for_endpoint()`.
+    pub(crate) fn paths_root() -> Self {
+        Self {
+            state: PathState::PathsRoot,
+        }
+    }
+
+    /// Return `true` if this stack has a root endpoint (not created via
+    /// `paths_root()`).
+    #[cfg(test)]
+    fn has_root(&self) -> bool {
+        !matches!(self.state, PathState::PathsRoot)
+    }
+
+    /// Return `true` if the current location is an endpoint (not a schema).
+    #[cfg(test)]
+    fn is_at_endpoint(&self) -> bool {
+        matches!(self.state, PathState::AtEndpoint(_))
+    }
+
+    /// Return `true` if the current location is a schema.
+    #[cfg(test)]
+    fn is_at_component(&self) -> bool {
+        matches!(self.state, PathState::AtComponent { .. })
+    }
+
+    /// Get the JSON pointer string for the current location.
+    pub fn current_pointer(&self) -> &str {
+        match &self.state {
+            PathState::PathsRoot => "#/paths",
+            PathState::AtEndpoint(path) => path.as_str(),
+            PathState::AtComponent { current, .. } => current.as_str(),
+        }
+    }
+
+    /// Append a path segment to the current location.
+    ///
+    /// This does not push a new reference; it extends the current path.
+    ///
+    /// # Panics
+    ///
+    /// Panics if called on a `paths_root()` stack (use `for_endpoint()` for traversal).
+    pub(crate) fn append(&self, segment: &str) -> JsonPathStack {
+        let state = match &self.state {
+            PathState::PathsRoot => {
+                panic!("cannot append to paths_root (use for_endpoint for traversal)")
+            }
+            PathState::AtEndpoint(path) => PathState::AtEndpoint(path.append(segment)),
+            PathState::AtComponent {
+                current,
+                origin_ref,
+                intermediate_refs,
+            } => PathState::AtComponent {
+                current: current.append(segment),
+                origin_ref: origin_ref.clone(),
+                intermediate_refs: intermediate_refs.clone(),
+            },
+        };
+        Self { state }
+    }
+
+    /// Push a schema reference onto the stack.
+    ///
+    /// This records the current location (with `/$ref` appended) in the
+    /// reference chain and sets the new current location to the schema path.
+    ///
+    /// Returns an error if `reference` is not a valid local schema path
+    /// (`#/...`).
+    ///
+    /// # Panics
+    ///
+    /// Panics if called on a `paths_root()` stack (a programming error).
+    pub(crate) fn push(&self, reference: &str) -> Result<JsonPathStack, InvalidComponentRef> {
+        let schema = RefTargetPath::parse(reference).ok_or_else(|| InvalidComponentRef {
+            reference: reference.to_string(),
+        })?;
+
+        let state = match &self.state {
+            PathState::PathsRoot => {
+                panic!("cannot push from paths_root (no endpoint context)")
+            }
+            PathState::AtEndpoint(path) => PathState::AtComponent {
+                current: schema,
+                origin_ref: path.append("$ref"),
+                intermediate_refs: Vec::new(),
+            },
+            PathState::AtComponent {
+                current,
+                origin_ref,
+                intermediate_refs,
+            } => {
+                let mut new_intermediates = intermediate_refs.clone();
+                new_intermediates.push(current.append("$ref"));
+                PathState::AtComponent {
+                    current: schema,
+                    origin_ref: origin_ref.clone(),
+                    intermediate_refs: new_intermediates,
+                }
+            }
+        };
+        Ok(Self { state })
+    }
+
+    /// Check if the stack contains a cycle.
+    ///
+    /// A cycle is detected when the current location is a path-segment-aligned
+    /// prefix of any entry in the reference chain. This means the current
+    /// schema (or an ancestor of it) was already visited, so descending into
+    /// it again would loop forever.
+    pub fn contains_cycle(&self) -> bool {
+        match &self.state {
+            PathState::PathsRoot | PathState::AtEndpoint(_) => false,
+            PathState::AtComponent {
+                current,
+                origin_ref,
+                intermediate_refs,
+            } => {
+                // In OAS 3.0, paths can `$ref` other paths, so we can't
+                // only look within intermediate_refs to check for cycles:
+                // there's a chance of a cycle involving the origin as well.
+                let current_str = current.as_str();
+                is_path_ancestor_of(current_str, origin_ref.as_str())
+                    || intermediate_refs
+                        .iter()
+                        .any(|r| is_path_ancestor_of(current_str, r.as_str()))
+            }
+        }
+    }
+
+    /// Iterate over the path reference stack from top (current) to bottom
+    /// (origin).
+    ///
+    /// This yields the current path first, then the reference chain in reverse
+    /// order (most recent reference first, origin endpoint last).
+    pub fn iter(&self) -> impl Iterator<Item = &str> {
+        match &self.state {
+            PathState::PathsRoot => {
+                Box::new(std::iter::once("#/paths")) as Box<dyn Iterator<Item = &str>>
+            }
+            PathState::AtEndpoint(path) => {
+                Box::new(std::iter::once(path.as_str())) as Box<dyn Iterator<Item = &str>>
+            }
+            PathState::AtComponent {
+                current,
+                origin_ref,
+                intermediate_refs,
+            } => Box::new(
+                std::iter::once(current.as_str())
+                    .chain(intermediate_refs.iter().rev().map(RefTargetPath::as_str))
+                    .chain(std::iter::once(origin_ref.as_str())),
+            ),
+        }
+    }
+}
+
+impl fmt::Debug for JsonPathStack {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        // Format as a list of strings for compatibility with existing tests.
+        let mut out = f.debug_list();
+        for path in self.iter() {
+            out.entry(&path);
+        }
+        out.finish()
+    }
+}
+
+impl fmt::Display for JsonPathStack {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let mut first = true;
+        for path in self.iter() {
+            if !first {
+                write!(f, " -> ")?;
+            }
+            write!(f, "{}", path)?;
+            first = false;
+        }
+        Ok(())
+    }
+}
+
+/// Escape a segment for use in a JSON pointer per RFC 6901.
+fn escape_json_pointer_segment(segment: &str) -> String {
+    segment.replace('~', "~0").replace('/', "~1")
+}
+
+/// Check if `ancestor` is a path-segment-aligned prefix of `path`.
+///
+/// Returns `true` if `path` starts with `ancestor` and the character
+/// immediately following the prefix (if any) is `/`. This prevents false
+/// matches where schema names share a common string prefix (e.g., `User`
+/// matching `UserProfile`).
+fn is_path_ancestor_of(ancestor: &str, path: &str) -> bool {
+    path.starts_with(ancestor)
+        && path
+            .as_bytes()
+            .get(ancestor.len())
+            .is_none_or(|&b| b == b'/')
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn endpoint_path_for_path() {
+        let path = EndpointPath::for_path("/users");
+        assert_eq!(path.as_str(), "#/paths/~1users");
+    }
+
+    #[test]
+    fn endpoint_path_for_path_escapes() {
+        // Paths with special characters get escaped.
+        let path = EndpointPath::for_path("/users/{id}/posts");
+        assert_eq!(path.as_str(), "#/paths/~1users~1{id}~1posts");
+    }
+
+    #[test]
+    fn endpoint_path_append() {
+        let path = EndpointPath::for_path("/users")
+            .append("get")
+            .append("responses");
+        assert_eq!(path.as_str(), "#/paths/~1users/get/responses");
+    }
+
+    #[test]
+    fn endpoint_path_append_escapes() {
+        let path = EndpointPath::for_path("/users")
+            .append("foo/bar")
+            .append("a~b");
+        assert_eq!(path.as_str(), "#/paths/~1users/foo~1bar/a~0b");
+    }
+
+    #[test]
+    fn component_path_parse_valid() {
+        let path = RefTargetPath::parse("#/components/schemas/User");
+        assert!(path.is_some());
+        assert_eq!(path.unwrap().as_str(), "#/components/schemas/User");
+    }
+
+    #[test]
+    fn component_path_parse_valid_various() {
+        // Any JSON pointer is valid.
+        assert!(RefTargetPath::parse("#/components/responses/NotFound").is_some());
+        assert!(RefTargetPath::parse("#/components/parameters/PageSize").is_some());
+        assert!(RefTargetPath::parse("#/paths/~1users/get").is_some());
+        assert!(RefTargetPath::parse("#/definitions/User").is_some());
+    }
+
+    #[test]
+    fn component_path_parse_invalid() {
+        // Must start with #/.
+        assert!(RefTargetPath::parse("components/schemas/User").is_none());
+        assert!(RefTargetPath::parse("/components/schemas/User").is_none());
+        assert!(RefTargetPath::parse("https://example.com/schema.json").is_none());
+    }
+
+    #[test]
+    fn component_path_append() {
+        let path = RefTargetPath::parse("#/components/schemas/User")
+            .unwrap()
+            .append("properties")
+            .append("name");
+        assert_eq!(path.as_str(), "#/components/schemas/User/properties/name");
+    }
+
+    #[test]
+    fn json_path_stack_for_endpoint() {
+        let endpoint = EndpointPath::for_path("/users").append("get");
+        let stack = JsonPathStack::for_endpoint(endpoint);
+
+        assert_eq!(stack.current_pointer(), "#/paths/~1users/get");
+        assert!(stack.is_at_endpoint());
+        assert!(stack.has_root());
+    }
+
+    #[test]
+    fn json_path_stack_paths_root() {
+        let stack = JsonPathStack::paths_root();
+
+        assert_eq!(stack.current_pointer(), "#/paths");
+        assert!(!stack.has_root());
+    }
+
+    #[test]
+    fn json_path_stack_append() {
+        let endpoint = EndpointPath::for_path("/users").append("get");
+        let stack = JsonPathStack::for_endpoint(endpoint)
+            .append("responses")
+            .append("200")
+            .append("schema");
+
+        assert_eq!(
+            stack.current_pointer(),
+            "#/paths/~1users/get/responses/200/schema"
+        );
+        assert!(stack.is_at_endpoint());
+    }
+
+    #[test]
+    fn json_path_stack_push() {
+        let endpoint = EndpointPath::for_path("/users").append("get");
+        let stack = JsonPathStack::for_endpoint(endpoint)
+            .append("responses")
+            .append("200")
+            .append("schema")
+            .push("#/components/schemas/User")
+            .unwrap();
+
+        assert_eq!(stack.current_pointer(), "#/components/schemas/User");
+        assert!(stack.is_at_component());
+
+        let entries: Vec<_> = stack.iter().collect();
+        assert_eq!(entries.len(), 2);
+        assert_eq!(entries[0], "#/components/schemas/User");
+        assert_eq!(entries[1], "#/paths/~1users/get/responses/200/schema/$ref");
+    }
+
+    #[test]
+    fn json_path_stack_cycle_detection() {
+        let endpoint = EndpointPath::for_path("/users").append("get");
+        let stack = JsonPathStack::for_endpoint(endpoint)
+            .push("#/components/schemas/User")
+            .unwrap()
+            .append("properties")
+            .append("manager");
+
+        // No cycle yet.
+        assert!(!stack.contains_cycle());
+
+        // Push a reference back to User, creating a cycle.
+        let stack = stack.push("#/components/schemas/User").unwrap();
+        assert!(stack.contains_cycle());
+    }
+
+    // Schemas whose names share a common string prefix must not be treated as
+    // cycles. e.g. "User" is a prefix of "UserProfile" at the string level, but
+    // they are different schemas.
+    #[test]
+    fn cycle_detection_no_false_positive_on_shared_prefix() {
+        let endpoint = EndpointPath::for_path("/users").append("get");
+
+        let stack = JsonPathStack::for_endpoint(endpoint)
+            .push("#/components/schemas/User")
+            .unwrap()
+            .append("properties")
+            .append("manager")
+            .push("#/components/schemas/UserProfile")
+            .unwrap();
+
+        assert!(!stack.contains_cycle());
+    }
+
+    #[test]
+    fn cycle_detection_no_false_positive_on_shared_prefix_origin() {
+        // The origin endpoint path could also be a string prefix of
+        // the current location without being an ancestor.
+        let endpoint = EndpointPath::for_path("/users").append("get");
+
+        // Follow a ref to a schema whose path happens to start with
+        // the same characters as the origin but at a different location.
+        let stack = JsonPathStack::for_endpoint(endpoint)
+            .push("#/paths/~1users/get-details")
+            .unwrap();
+
+        // "AB" is not "A": no cycle, even though "A" is a string prefix
+        // of "AB".
+        assert!(!stack.contains_cycle());
+    }
+
+    #[test]
+    fn cycle_detection_true_positive_through_subpath() {
+        // A cycle exists when the current schema is an ancestor of a
+        // previously visited location (we'd descend into the same subtree).
+        let endpoint = EndpointPath::for_path("/users").append("get");
+        let stack = JsonPathStack::for_endpoint(endpoint)
+            .push("#/components/schemas/User")
+            .unwrap()
+            .append("properties")
+            .append("address")
+            .push("#/components/schemas/Address")
+            .unwrap()
+            .append("properties")
+            .append("owner")
+            // Cycle back to User: User -> ... -> Address -> ... -> User.
+            .push("#/components/schemas/User")
+            .unwrap();
+
+        assert!(stack.contains_cycle());
+    }
+
+    #[test]
+    fn is_path_ancestor_of_basics() {
+        // Exact match (after stripping /$ref the paths are equal).
+        assert!(is_path_ancestor_of(
+            "#/components/schemas/User",
+            "#/components/schemas/User/$ref"
+        ));
+
+        // True ancestor: current is a parent of the chain entry.
+        assert!(is_path_ancestor_of(
+            "#/components/schemas/User",
+            "#/components/schemas/User/properties/name/$ref"
+        ));
+
+        // False: shared string prefix but different schema name.
+        assert!(!is_path_ancestor_of(
+            "#/components/schemas/User",
+            "#/components/schemas/UserProfile/$ref"
+        ));
+
+        // False: completely unrelated paths.
+        assert!(!is_path_ancestor_of(
+            "#/components/schemas/User",
+            "#/components/schemas/Address/$ref"
+        ));
+
+        // Edge: ancestor equals path exactly (no trailing content).
+        assert!(is_path_ancestor_of(
+            "#/components/schemas/User",
+            "#/components/schemas/User"
+        ));
+    }
+
+    #[test]
+    fn json_path_stack_iter_order() {
+        let endpoint = EndpointPath::for_path("/users").append("get");
+        let stack = JsonPathStack::for_endpoint(endpoint)
+            .push("#/components/schemas/A")
+            .unwrap()
+            .push("#/components/schemas/B")
+            .unwrap();
+
+        let entries: Vec<_> = stack.iter().collect();
+        assert_eq!(entries.len(), 3);
+        // Current is first.
+        assert_eq!(entries[0], "#/components/schemas/B");
+        // Then refs in reverse order (most recent first).
+        assert_eq!(entries[1], "#/components/schemas/A/$ref");
+        // Origin is last.
+        assert_eq!(entries[2], "#/paths/~1users/get/$ref");
+    }
+
+    #[test]
+    fn json_path_stack_display() {
+        let endpoint = EndpointPath::for_path("/users").append("get");
+        let stack = JsonPathStack::for_endpoint(endpoint)
+            .push("#/components/schemas/User")
+            .unwrap();
+
+        let displayed = format!("{}", stack);
+        assert_eq!(
+            displayed,
+            "#/components/schemas/User -> #/paths/~1users/get/$ref"
+        );
+    }
+
+    #[test]
+    fn json_path_stack_push_invalid_ref_returns_error() {
+        let endpoint = EndpointPath::for_path("/users").append("get");
+        let stack = JsonPathStack::for_endpoint(endpoint);
+
+        let err = stack
+            .push("not/a/json/pointer")
+            .expect_err("expected error for invalid reference");
+
+        assert_eq!(err.reference, "not/a/json/pointer");
+        assert_eq!(
+            err.to_string(),
+            "invalid reference \"not/a/json/pointer\": \
+             expected JSON pointer starting with #/"
+        );
+    }
+}
diff --git a/src/resolve.rs b/src/resolve.rs
index e828842..187191e 100644
--- a/src/resolve.rs
+++ b/src/resolve.rs
@@ -1,4 +1,4 @@
-// Copyright 2025 Oxide Computer Company
+// Copyright 2026 Oxide Computer Company
 
 use std::borrow::Cow;
 
@@ -33,8 +33,7 @@ where
         };
 
         loop {
-            assert!(target.starts_with("#/"));
-            context = context.push(target.as_ref());
+            context = context.push(target.as_ref())?;
 
             let subtree = context
                 .raw_openapi
diff --git a/src/schema.rs b/src/schema.rs
index 133c978..30b5faf 100644
--- a/src/schema.rs
+++ b/src/schema.rs
@@ -1,4 +1,4 @@
-// Copyright 2025 Oxide Computer Company
+// Copyright 2026 Oxide Computer Company
 
 use std::fmt;
 
@@ -6,7 +6,7 @@ use openapiv3::{AdditionalProperties, ArrayType, ObjectType, ReferenceOr, Schema
 
 use crate::{
     ChangeClass, ChangeComparison, ChangeDetails,
-    compare::Compare,
+    compare::{Compare, VisitedKey},
     context::{Contextual, ToContext},
     setops::SetCompare,
 };
@@ -198,11 +198,12 @@ impl Compare {
 
         // Return the cached compatibility of these schemas so that we don't
         // generate redundant notes.
-        if let Some(equal) = self.visited.get(&(
+        let key = VisitedKey::new(
             comparison,
-            old_schema.context().stack().top.clone(),
-            new_schema.context().stack().top.clone(),
-        )) {
+            old_schema.context().stack(),
+            new_schema.context().stack(),
+        );
+        if let Some(equal) = self.visited.get(&key) {
             return Ok(*equal);
         }
 
@@ -276,14 +277,7 @@ impl Compare {
         )?;
 
         // Cache the result.
-        self.visited.insert(
-            (
-                comparison,
-                old_schema.context().stack().top.clone(),
-                new_schema.context().stack().top.clone(),
-            ),
-            nullable_equal && schema_equal,
-        );
+        self.visited.insert(key, nullable_equal && schema_equal);
 
         Ok(nullable_equal && schema_equal)
     }
diff --git a/tests/cases/simple/output/add-cookie-parameter.out b/tests/cases/simple/output/add-cookie-parameter.out
index 805b882..589dbfd 100644
--- a/tests/cases/simple/output/add-cookie-parameter.out
+++ b/tests/cases/simple/output/add-cookie-parameter.out
@@ -1,6 +1,6 @@
 --- add-cookie-parameter.json
 +++ patched
-@@ -365,6 +365,16 @@
+@@
        "get": {
          "description": "A simple ping endpoint that does nothing.",
          "operationId": "ping",
@@ -22,15 +22,25 @@
 Result for patch:
 [
     Change {
-        message: "A new, optional parameter 'tracking' was added",
-        old_path: [
-            "#/paths/~1ping/get",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1ping/get",
+                ],
+                new: [
+                    "#/paths/~1ping/get/parameters/0",
+                ],
+                comparison: Input,
+            },
         ],
-        new_path: [
-            "#/paths/~1ping/get/parameters/0",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "A new, optional parameter 'tracking' was added",
+                class: ForwardIncompatible,
+                details: Added,
+            },
         ],
-        comparison: Input,
-        class: ForwardIncompatible,
-        details: Added,
     },
 ]
diff --git a/tests/cases/simple/output/add-default-response.out b/tests/cases/simple/output/add-default-response.out
index 712492a..9396245 100644
--- a/tests/cases/simple/output/add-default-response.out
+++ b/tests/cases/simple/output/add-default-response.out
@@ -1,6 +1,6 @@
 --- add-default-response.json
 +++ patched
-@@ -368,6 +368,16 @@
+@@
          "responses": {
            "200": {
              "description": "Ping successful"
@@ -22,15 +22,25 @@
 Result for patch:
 [
     Change {
-        message: "operation added a default response",
-        old_path: [
-            "#/paths/~1ping/get",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1ping/get",
+                ],
+                new: [
+                    "#/paths/~1ping/get",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/paths/~1ping/get",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "operation added a default response",
+                class: Unhandled,
+                details: Added,
+            },
         ],
-        comparison: Output,
-        class: Unhandled,
-        details: Added,
     },
 ]
diff --git a/tests/cases/simple/output/add-header-parameter.out b/tests/cases/simple/output/add-header-parameter.out
index 006a63b..4983e6b 100644
--- a/tests/cases/simple/output/add-header-parameter.out
+++ b/tests/cases/simple/output/add-header-parameter.out
@@ -1,6 +1,6 @@
 --- add-header-parameter.json
 +++ patched
-@@ -365,6 +365,16 @@
+@@
        "get": {
          "description": "A simple ping endpoint that does nothing.",
          "operationId": "ping",
@@ -22,15 +22,25 @@
 Result for patch:
 [
     Change {
-        message: "A new, optional parameter 'X-Trace-Id' was added",
-        old_path: [
-            "#/paths/~1ping/get",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1ping/get",
+                ],
+                new: [
+                    "#/paths/~1ping/get/parameters/0",
+                ],
+                comparison: Input,
+            },
         ],
-        new_path: [
-            "#/paths/~1ping/get/parameters/0",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "A new, optional parameter 'X-Trace-Id' was added",
+                class: ForwardIncompatible,
+                details: Added,
+            },
         ],
-        comparison: Input,
-        class: ForwardIncompatible,
-        details: Added,
     },
 ]
diff --git a/tests/cases/simple/output/add-operation-with-id.out b/tests/cases/simple/output/add-operation-with-id.out
index 7b51342..16de102 100644
--- a/tests/cases/simple/output/add-operation-with-id.out
+++ b/tests/cases/simple/output/add-operation-with-id.out
@@ -1,6 +1,6 @@
 --- add-operation-with-id.json
 +++ patched
-@@ -314,6 +314,17 @@
+@@
          "summary": "Update an item"
        }
      },
@@ -23,15 +23,25 @@
 Result for patch:
 [
     Change {
-        message: "The operation new_endpoint was added",
-        old_path: [
-            "#/paths",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths",
+                ],
+                new: [
+                    "#/paths/~1new-endpoint/get",
+                ],
+                comparison: Structural,
+            },
         ],
-        new_path: [
-            "#/paths/~1new-endpoint/get",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "The operation new_endpoint was added",
+                class: ForwardIncompatible,
+                details: Added,
+            },
         ],
-        comparison: Structural,
-        class: ForwardIncompatible,
-        details: Added,
     },
 ]
diff --git a/tests/cases/simple/output/add-operation.out b/tests/cases/simple/output/add-operation.out
index f938e86..23d6f9b 100644
--- a/tests/cases/simple/output/add-operation.out
+++ b/tests/cases/simple/output/add-operation.out
@@ -1,6 +1,6 @@
 --- add-operation.json
 +++ patched
-@@ -238,6 +238,16 @@
+@@
          "summary": "Get arrays"
        }
      },
@@ -22,15 +22,25 @@
 Result for patch:
 [
     Change {
-        message: "The operation <unnamed> was added",
-        old_path: [
-            "#/paths",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths",
+                ],
+                new: [
+                    "#/paths/~1foo/get",
+                ],
+                comparison: Structural,
+            },
         ],
-        new_path: [
-            "#/paths/~1foo/get",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "The operation <unnamed> was added",
+                class: ForwardIncompatible,
+                details: Added,
+            },
         ],
-        comparison: Structural,
-        class: ForwardIncompatible,
-        details: Added,
     },
 ]
diff --git a/tests/cases/simple/output/add-optional-body.out b/tests/cases/simple/output/add-optional-body.out
index 75fe676..6d3527d 100644
--- a/tests/cases/simple/output/add-optional-body.out
+++ b/tests/cases/simple/output/add-optional-body.out
@@ -1,6 +1,6 @@
 --- add-optional-body.json
 +++ patched
-@@ -317,6 +317,21 @@
+@@
      "/no-body": {
        "post": {
          "operationId": "no_body",
@@ -27,15 +27,25 @@
 Result for patch:
 [
     Change {
-        message: "no body parameter was specified and now one is accepted",
-        old_path: [
-            "#/paths/~1no-body/post",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1no-body/post",
+                ],
+                new: [
+                    "#/paths/~1no-body/post",
+                ],
+                comparison: Input,
+            },
         ],
-        new_path: [
-            "#/paths/~1no-body/post",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "no body parameter was specified and now one is accepted",
+                class: ForwardIncompatible,
+                details: Added,
+            },
         ],
-        comparison: Input,
-        class: ForwardIncompatible,
-        details: Added,
     },
 ]
diff --git a/tests/cases/simple/output/add-optional-parameter.out b/tests/cases/simple/output/add-optional-parameter.out
index 34b0217..090280d 100644
--- a/tests/cases/simple/output/add-optional-parameter.out
+++ b/tests/cases/simple/output/add-optional-parameter.out
@@ -1,6 +1,6 @@
 --- add-optional-parameter.json
 +++ patched
-@@ -257,6 +257,15 @@
+@@
              "schema": {
                "type": "string"
              }
@@ -21,15 +21,25 @@
 Result for patch:
 [
     Change {
-        message: "A new, optional parameter 'limit' was added",
-        old_path: [
-            "#/paths/~1hello~1{name}/get",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1hello~1{name}/get",
+                ],
+                new: [
+                    "#/paths/~1hello~1{name}/get/parameters/2",
+                ],
+                comparison: Input,
+            },
         ],
-        new_path: [
-            "#/paths/~1hello~1{name}/get/parameters/2",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "A new, optional parameter 'limit' was added",
+                class: ForwardIncompatible,
+                details: Added,
+            },
         ],
-        comparison: Input,
-        class: ForwardIncompatible,
-        details: Added,
     },
 ]
diff --git a/tests/cases/simple/output/add-required-body.out b/tests/cases/simple/output/add-required-body.out
index 47d7d4e..4c76e6c 100644
--- a/tests/cases/simple/output/add-required-body.out
+++ b/tests/cases/simple/output/add-required-body.out
@@ -1,6 +1,6 @@
 --- add-required-body.json
 +++ patched
-@@ -317,6 +317,21 @@
+@@
      "/no-body": {
        "post": {
          "operationId": "no_body",
@@ -27,15 +27,25 @@
 Result for patch:
 [
     Change {
-        message: "no body parameter was specified and now one is required",
-        old_path: [
-            "#/paths/~1no-body/post",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1no-body/post",
+                ],
+                new: [
+                    "#/paths/~1no-body/post",
+                ],
+                comparison: Input,
+            },
         ],
-        new_path: [
-            "#/paths/~1no-body/post",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "no body parameter was specified and now one is required",
+                class: Incompatible,
+                details: AddedRequired,
+            },
         ],
-        comparison: Input,
-        class: Incompatible,
-        details: AddedRequired,
     },
 ]
diff --git a/tests/cases/simple/output/add-required-parameter.out b/tests/cases/simple/output/add-required-parameter.out
index b2e82b0..ab0ae99 100644
--- a/tests/cases/simple/output/add-required-parameter.out
+++ b/tests/cases/simple/output/add-required-parameter.out
@@ -1,6 +1,6 @@
 --- add-required-parameter.json
 +++ patched
-@@ -257,6 +257,15 @@
+@@
              "schema": {
                "type": "string"
              }
@@ -21,15 +21,25 @@
 Result for patch:
 [
     Change {
-        message: "A new, required parameter 'format' was added",
-        old_path: [
-            "#/paths/~1hello~1{name}/get",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1hello~1{name}/get",
+                ],
+                new: [
+                    "#/paths/~1hello~1{name}/get/parameters/2",
+                ],
+                comparison: Input,
+            },
         ],
-        new_path: [
-            "#/paths/~1hello~1{name}/get/parameters/2",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "A new, required parameter 'format' was added",
+                class: BackwardIncompatible,
+                details: AddedRequired,
+            },
         ],
-        comparison: Input,
-        class: BackwardIncompatible,
-        details: AddedRequired,
     },
 ]
diff --git a/tests/cases/simple/output/add-response-code.out b/tests/cases/simple/output/add-response-code.out
index 4d98490..0181b93 100644
--- a/tests/cases/simple/output/add-response-code.out
+++ b/tests/cases/simple/output/add-response-code.out
@@ -1,6 +1,6 @@
 --- add-response-code.json
 +++ patched
-@@ -368,6 +368,9 @@
+@@
          "responses": {
            "200": {
              "description": "Ping successful"
@@ -15,15 +15,25 @@
 Result for patch:
 [
     Change {
-        message: "operation added a new response code 500",
-        old_path: [
-            "#/paths/~1ping/get",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1ping/get",
+                ],
+                new: [
+                    "#/paths/~1ping/get",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/paths/~1ping/get",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "operation added a new response code 500",
+                class: BackwardIncompatible,
+                details: Added,
+            },
         ],
-        comparison: Output,
-        class: BackwardIncompatible,
-        details: Added,
     },
 ]
diff --git a/tests/cases/simple/output/add-type-extension.out b/tests/cases/simple/output/add-type-extension.out
index 2b9722c..94545a5 100644
--- a/tests/cases/simple/output/add-type-extension.out
+++ b/tests/cases/simple/output/add-type-extension.out
@@ -1,6 +1,6 @@
 --- add-type-extension.json
 +++ patched
-@@ -88,7 +88,10 @@
+@@
          "required": [
            "message"
          ],
@@ -17,17 +17,27 @@
 Result for patch:
 [
     Change {
-        message: "schema metadata changed",
-        old_path: [
-            "#/components/schemas/GreetingResponse",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/GreetingResponse",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponse",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponse",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema metadata changed",
+                class: Trivial,
+                details: Metadata,
+            },
         ],
-        comparison: Output,
-        class: Trivial,
-        details: Metadata,
     },
 ]
diff --git a/tests/cases/simple/output/allof-to-anyof.out b/tests/cases/simple/output/allof-to-anyof.out
index c65c7a9..b81e3bd 100644
--- a/tests/cases/simple/output/allof-to-anyof.out
+++ b/tests/cases/simple/output/allof-to-anyof.out
@@ -1,6 +1,6 @@
 --- allof-to-anyof.json
 +++ patched
-@@ -58,12 +58,12 @@
+@@
              }
            },
            "via_allof": {
@@ -20,17 +20,27 @@
 Result for patch:
 [
     Change {
-        message: "schema metadata changed",
-        old_path: [
-            "#/components/schemas/GreetingResponse/properties/via_allof",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/GreetingResponse/properties/via_allof",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponse/properties/via_allof",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponse/properties/via_allof",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema metadata changed",
+                class: Trivial,
+                details: Metadata,
+            },
         ],
-        comparison: Output,
-        class: Trivial,
-        details: Metadata,
     },
 ]
diff --git a/tests/cases/simple/output/allof-to-oneof-with-type-change.out b/tests/cases/simple/output/allof-to-oneof-with-type-change.out
index 2712e0a..ed44066 100644
--- a/tests/cases/simple/output/allof-to-oneof-with-type-change.out
+++ b/tests/cases/simple/output/allof-to-oneof-with-type-change.out
@@ -1,6 +1,6 @@
 --- allof-to-oneof-with-type-change.json
 +++ patched
-@@ -58,12 +58,12 @@
+@@
              }
            },
            "via_allof": {
@@ -16,7 +16,7 @@
            },
            "via_anyof": {
              "anyOf": [
-@@ -137,7 +137,7 @@
+@@
        "SubType": {
          "properties": {
            "value": {
@@ -30,33 +30,53 @@
 Result for patch:
 [
     Change {
-        message: "schema metadata changed",
-        old_path: [
-            "#/components/schemas/GreetingResponse/properties/via_allof",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/GreetingResponse/properties/via_allof",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponse/properties/via_allof",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponse/properties/via_allof",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema metadata changed",
+                class: Trivial,
+                details: Metadata,
+            },
         ],
-        comparison: Output,
-        class: Trivial,
-        details: Metadata,
     },
     Change {
-        message: "schema types changed",
-        old_path: [
-            "#/components/schemas/SubType/properties/value",
-            "#/components/schemas/GreetingResponse/properties/via_allof/0/$ref",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/SubType/properties/value",
+                    "#/components/schemas/GreetingResponse/properties/via_allof/0/$ref",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/SubType/properties/value",
+                    "#/components/schemas/GreetingResponse/properties/via_allof/0/$ref",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/SubType/properties/value",
-            "#/components/schemas/GreetingResponse/properties/via_allof/0/$ref",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema types changed",
+                class: Incompatible,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Incompatible,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/allof-to-oneof.out b/tests/cases/simple/output/allof-to-oneof.out
index 14f9d00..138bba1 100644
--- a/tests/cases/simple/output/allof-to-oneof.out
+++ b/tests/cases/simple/output/allof-to-oneof.out
@@ -1,6 +1,6 @@
 --- allof-to-oneof.json
 +++ patched
-@@ -58,12 +58,12 @@
+@@
              }
            },
            "via_allof": {
@@ -21,17 +21,27 @@
 Result for patch:
 [
     Change {
-        message: "schema metadata changed",
-        old_path: [
-            "#/components/schemas/GreetingResponse/properties/via_allof",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/GreetingResponse/properties/via_allof",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponse/properties/via_allof",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponse/properties/via_allof",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema metadata changed",
+                class: Trivial,
+                details: Metadata,
+            },
         ],
-        comparison: Output,
-        class: Trivial,
-        details: Metadata,
     },
 ]
diff --git a/tests/cases/simple/output/allof-to-ref-with-type-change.out b/tests/cases/simple/output/allof-to-ref-with-type-change.out
index f4d9b89..b9e4d5d 100644
--- a/tests/cases/simple/output/allof-to-ref-with-type-change.out
+++ b/tests/cases/simple/output/allof-to-ref-with-type-change.out
@@ -1,6 +1,6 @@
 --- allof-to-ref-with-type-change.json
 +++ patched
-@@ -58,12 +58,7 @@
+@@
              }
            },
            "via_allof": {
@@ -14,7 +14,7 @@
            },
            "via_anyof": {
              "anyOf": [
-@@ -136,6 +131,9 @@
+@@
        },
        "SubType": {
          "properties": {
@@ -29,33 +29,53 @@
 Result for patch:
 [
     Change {
-        message: "schema metadata removed",
-        old_path: [
-            "#/components/schemas/GreetingResponse/properties/via_allof",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/GreetingResponse/properties/via_allof",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponse/properties/via_allof",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponse/properties/via_allof",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema metadata removed",
+                class: Trivial,
+                details: Metadata,
+            },
         ],
-        comparison: Output,
-        class: Trivial,
-        details: Metadata,
     },
     Change {
-        message: "object properties changed",
-        old_path: [
-            "#/components/schemas/SubType",
-            "#/components/schemas/GreetingResponse/properties/via_allof/0/$ref",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/SubType",
+                    "#/components/schemas/GreetingResponse/properties/via_allof/0/$ref",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/SubType",
+                    "#/components/schemas/GreetingResponse/properties/via_allof/$ref",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/SubType",
-            "#/components/schemas/GreetingResponse/properties/via_allof/$ref",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "object properties changed",
+                class: Unhandled,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Unhandled,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/allof-to-ref.out b/tests/cases/simple/output/allof-to-ref.out
index 7f3de13..f678b9f 100644
--- a/tests/cases/simple/output/allof-to-ref.out
+++ b/tests/cases/simple/output/allof-to-ref.out
@@ -1,6 +1,6 @@
 --- allof-to-ref.json
 +++ patched
-@@ -58,12 +58,7 @@
+@@
              }
            },
            "via_allof": {
@@ -19,17 +19,27 @@
 Result for patch:
 [
     Change {
-        message: "schema metadata removed",
-        old_path: [
-            "#/components/schemas/GreetingResponse/properties/via_allof",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/GreetingResponse/properties/via_allof",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponse/properties/via_allof",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponse/properties/via_allof",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema metadata removed",
+                class: Trivial,
+                details: Metadata,
+            },
         ],
-        comparison: Output,
-        class: Trivial,
-        details: Metadata,
     },
 ]
diff --git a/tests/cases/simple/output/any-schema-change.out b/tests/cases/simple/output/any-schema-change.out
index 35a3e91..6946867 100644
--- a/tests/cases/simple/output/any-schema-change.out
+++ b/tests/cases/simple/output/any-schema-change.out
@@ -1,6 +1,6 @@
 --- any-schema-change.json
 +++ patched
-@@ -48,6 +48,7 @@
+@@
        },
        "GreetingResponse": {
          "properties": {
@@ -13,17 +13,27 @@
 Result for patch:
 [
     Change {
-        message: "object properties changed",
-        old_path: [
-            "#/components/schemas/GreetingResponse",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/GreetingResponse",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponse",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponse",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "object properties changed",
+                class: Unhandled,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Unhandled,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/anyof-to-allof.out b/tests/cases/simple/output/anyof-to-allof.out
index ced8976..882217b 100644
--- a/tests/cases/simple/output/anyof-to-allof.out
+++ b/tests/cases/simple/output/anyof-to-allof.out
@@ -1,6 +1,6 @@
 --- anyof-to-allof.json
 +++ patched
-@@ -66,12 +66,12 @@
+@@
              "description": "Via allOf."
            },
            "via_anyof": {
@@ -20,17 +20,27 @@
 Result for patch:
 [
     Change {
-        message: "schema metadata changed",
-        old_path: [
-            "#/components/schemas/GreetingResponse/properties/via_anyof",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/GreetingResponse/properties/via_anyof",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponse/properties/via_anyof",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponse/properties/via_anyof",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema metadata changed",
+                class: Trivial,
+                details: Metadata,
+            },
         ],
-        comparison: Output,
-        class: Trivial,
-        details: Metadata,
     },
 ]
diff --git a/tests/cases/simple/output/anyof-to-oneof.out b/tests/cases/simple/output/anyof-to-oneof.out
index 0e1f38d..95136e7 100644
--- a/tests/cases/simple/output/anyof-to-oneof.out
+++ b/tests/cases/simple/output/anyof-to-oneof.out
@@ -1,6 +1,6 @@
 --- anyof-to-oneof.json
 +++ patched
-@@ -66,12 +66,12 @@
+@@
              "description": "Via allOf."
            },
            "via_anyof": {
@@ -21,17 +21,27 @@
 Result for patch:
 [
     Change {
-        message: "schema metadata changed",
-        old_path: [
-            "#/components/schemas/GreetingResponse/properties/via_anyof",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/GreetingResponse/properties/via_anyof",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponse/properties/via_anyof",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponse/properties/via_anyof",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema metadata changed",
+                class: Trivial,
+                details: Metadata,
+            },
         ],
-        comparison: Output,
-        class: Trivial,
-        details: Metadata,
     },
 ]
diff --git a/tests/cases/simple/output/anyof-to-ref.out b/tests/cases/simple/output/anyof-to-ref.out
index 2e1d099..d4cc3d9 100644
--- a/tests/cases/simple/output/anyof-to-ref.out
+++ b/tests/cases/simple/output/anyof-to-ref.out
@@ -1,6 +1,6 @@
 --- anyof-to-ref.json
 +++ patched
-@@ -66,12 +66,7 @@
+@@
              "description": "Via allOf."
            },
            "via_anyof": {
@@ -19,17 +19,27 @@
 Result for patch:
 [
     Change {
-        message: "schema metadata removed",
-        old_path: [
-            "#/components/schemas/GreetingResponse/properties/via_anyof",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/GreetingResponse/properties/via_anyof",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponse/properties/via_anyof",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponse/properties/via_anyof",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema metadata removed",
+                class: Trivial,
+                details: Metadata,
+            },
         ],
-        comparison: Output,
-        class: Trivial,
-        details: Metadata,
     },
 ]
diff --git a/tests/cases/simple/output/array-items-add.out b/tests/cases/simple/output/array-items-add.out
index f197b94..ff3f591 100644
--- a/tests/cases/simple/output/array-items-add.out
+++ b/tests/cases/simple/output/array-items-add.out
@@ -1,6 +1,6 @@
 --- array-items-add.json
 +++ patched
-@@ -12,9 +12,6 @@
+@@
          ]
        },
        "ArrayWithConstraints": {
@@ -15,17 +15,27 @@
 Result for patch:
 [
     Change {
-        message: "array items changed",
-        old_path: [
-            "#/components/schemas/ArrayWithConstraints",
-            "#/paths/~1arrays/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/ArrayWithConstraints",
+                    "#/paths/~1arrays/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/ArrayWithConstraints",
+                    "#/paths/~1arrays/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/ArrayWithConstraints",
-            "#/paths/~1arrays/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "array items changed",
+                class: Unhandled,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Unhandled,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/array-items-remove.out b/tests/cases/simple/output/array-items-remove.out
index 426e982..0d4f31e 100644
--- a/tests/cases/simple/output/array-items-remove.out
+++ b/tests/cases/simple/output/array-items-remove.out
@@ -1,6 +1,6 @@
 --- array-items-remove.json
 +++ patched
-@@ -146,7 +146,7 @@
+@@
          "properties": {
            "children": {
              "items": {
@@ -14,18 +14,28 @@
 Result for patch:
 [
     Change {
-        message: "schema types changed",
-        old_path: [
-            "#/components/schemas/Tree",
-            "#/components/schemas/Tree/properties/children/items/$ref",
-            "#/paths/~1tree/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/Tree",
+                    "#/components/schemas/Tree/properties/children/items/$ref",
+                    "#/paths/~1tree/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/Tree/properties/children/items",
+                    "#/paths/~1tree/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/Tree/properties/children/items",
-            "#/paths/~1tree/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema types changed",
+                class: Incompatible,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Incompatible,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/array-max-items-change.out b/tests/cases/simple/output/array-max-items-change.out
index b00e190..1057ee5 100644
--- a/tests/cases/simple/output/array-max-items-change.out
+++ b/tests/cases/simple/output/array-max-items-change.out
@@ -1,6 +1,6 @@
 --- array-max-items-change.json
 +++ patched
-@@ -15,7 +15,7 @@
+@@
          "items": {
            "type": "string"
          },
@@ -14,17 +14,27 @@
 Result for patch:
 [
     Change {
-        message: "array maxItems changed",
-        old_path: [
-            "#/components/schemas/ArrayWithConstraints",
-            "#/paths/~1arrays/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/ArrayWithConstraints",
+                    "#/paths/~1arrays/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/ArrayWithConstraints",
+                    "#/paths/~1arrays/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/ArrayWithConstraints",
-            "#/paths/~1arrays/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "array maxItems changed",
+                class: Unhandled,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Unhandled,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/array-min-items-change.out b/tests/cases/simple/output/array-min-items-change.out
index df42d55..d2e39df 100644
--- a/tests/cases/simple/output/array-min-items-change.out
+++ b/tests/cases/simple/output/array-min-items-change.out
@@ -1,6 +1,6 @@
 --- array-min-items-change.json
 +++ patched
-@@ -16,7 +16,7 @@
+@@
            "type": "string"
          },
          "maxItems": 10,
@@ -14,17 +14,27 @@
 Result for patch:
 [
     Change {
-        message: "array minItems changed",
-        old_path: [
-            "#/components/schemas/ArrayWithConstraints",
-            "#/paths/~1arrays/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/ArrayWithConstraints",
+                    "#/paths/~1arrays/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/ArrayWithConstraints",
+                    "#/paths/~1arrays/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/ArrayWithConstraints",
-            "#/paths/~1arrays/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "array minItems changed",
+                class: Unhandled,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Unhandled,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/array-unique-items-change.out b/tests/cases/simple/output/array-unique-items-change.out
index 34e50e4..3561ec6 100644
--- a/tests/cases/simple/output/array-unique-items-change.out
+++ b/tests/cases/simple/output/array-unique-items-change.out
@@ -1,6 +1,6 @@
 --- array-unique-items-change.json
 +++ patched
-@@ -18,7 +18,7 @@
+@@
          "maxItems": 10,
          "minItems": 1,
          "type": "array",
@@ -14,17 +14,27 @@
 Result for patch:
 [
     Change {
-        message: "array uniqueItems changed",
-        old_path: [
-            "#/components/schemas/ArrayWithConstraints",
-            "#/paths/~1arrays/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/ArrayWithConstraints",
+                    "#/paths/~1arrays/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/ArrayWithConstraints",
+                    "#/paths/~1arrays/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/ArrayWithConstraints",
-            "#/paths/~1arrays/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "array uniqueItems changed",
+                class: Unhandled,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Unhandled,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/body-description-change.out b/tests/cases/simple/output/body-description-change.out
index 3e2eb01..70d0cf7 100644
--- a/tests/cases/simple/output/body-description-change.out
+++ b/tests/cases/simple/output/body-description-change.out
@@ -1,6 +1,6 @@
 --- body-description-change.json
 +++ patched
-@@ -285,6 +285,7 @@
+@@
                }
              }
            },
@@ -13,15 +13,25 @@
 Result for patch:
 [
     Change {
-        message: "the body metadata (description or extensions) changed",
-        old_path: [
-            "#/paths/~1items/post",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1items/post",
+                ],
+                new: [
+                    "#/paths/~1items/post",
+                ],
+                comparison: Input,
+            },
         ],
-        new_path: [
-            "#/paths/~1items/post",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "the body metadata (description or extensions) changed",
+                class: Trivial,
+                details: Metadata,
+            },
         ],
-        comparison: Input,
-        class: Trivial,
-        details: Metadata,
     },
 ]
diff --git a/tests/cases/simple/output/body-extension-change.out b/tests/cases/simple/output/body-extension-change.out
index 06cbc81..412535e 100644
--- a/tests/cases/simple/output/body-extension-change.out
+++ b/tests/cases/simple/output/body-extension-change.out
@@ -1,6 +1,6 @@
 --- body-extension-change.json
 +++ patched
-@@ -285,7 +285,8 @@
+@@
                }
              }
            },
@@ -15,15 +15,25 @@
 Result for patch:
 [
     Change {
-        message: "the body metadata (description or extensions) changed",
-        old_path: [
-            "#/paths/~1items/post",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1items/post",
+                ],
+                new: [
+                    "#/paths/~1items/post",
+                ],
+                comparison: Input,
+            },
         ],
-        new_path: [
-            "#/paths/~1items/post",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "the body metadata (description or extensions) changed",
+                class: Trivial,
+                details: Metadata,
+            },
         ],
-        comparison: Input,
-        class: Trivial,
-        details: Metadata,
     },
 ]
diff --git a/tests/cases/simple/output/body-optional-to-required.out b/tests/cases/simple/output/body-optional-to-required.out
index b09a68f..1140bc4 100644
--- a/tests/cases/simple/output/body-optional-to-required.out
+++ b/tests/cases/simple/output/body-optional-to-required.out
@@ -1,6 +1,6 @@
 --- body-optional-to-required.json
 +++ patched
-@@ -304,7 +304,7 @@
+@@
                }
              }
            },
@@ -14,15 +14,25 @@
 Result for patch:
 [
     Change {
-        message: "the body parameter was optional and is now required",
-        old_path: [
-            "#/paths/~1items/put",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1items/put",
+                ],
+                new: [
+                    "#/paths/~1items/put",
+                ],
+                comparison: Input,
+            },
         ],
-        new_path: [
-            "#/paths/~1items/put",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "the body parameter was optional and is now required",
+                class: BackwardIncompatible,
+                details: MoreStrict,
+            },
         ],
-        comparison: Input,
-        class: BackwardIncompatible,
-        details: MoreStrict,
     },
 ]
diff --git a/tests/cases/simple/output/body-required-to-optional.out b/tests/cases/simple/output/body-required-to-optional.out
index a41b06d..1216579 100644
--- a/tests/cases/simple/output/body-required-to-optional.out
+++ b/tests/cases/simple/output/body-required-to-optional.out
@@ -1,6 +1,6 @@
 --- body-required-to-optional.json
 +++ patched
-@@ -285,7 +285,7 @@
+@@
                }
              }
            },
@@ -14,15 +14,25 @@
 Result for patch:
 [
     Change {
-        message: "the body parameter was required and is now optional",
-        old_path: [
-            "#/paths/~1items/post",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1items/post",
+                ],
+                new: [
+                    "#/paths/~1items/post",
+                ],
+                comparison: Input,
+            },
         ],
-        new_path: [
-            "#/paths/~1items/post",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "the body parameter was required and is now optional",
+                class: ForwardIncompatible,
+                details: LessStrict,
+            },
         ],
-        comparison: Input,
-        class: ForwardIncompatible,
-        details: LessStrict,
     },
 ]
diff --git a/tests/cases/simple/output/boolean-change.out b/tests/cases/simple/output/boolean-change.out
index 6fc74f3..9d002e0 100644
--- a/tests/cases/simple/output/boolean-change.out
+++ b/tests/cases/simple/output/boolean-change.out
@@ -1,6 +1,6 @@
 --- boolean-change.json
 +++ patched
-@@ -159,6 +159,7 @@
+@@
              "type": "integer"
            },
            "enabled": {
@@ -13,17 +13,27 @@
 Result for patch:
 [
     Change {
-        message: "schema metadata changed",
-        old_path: [
-            "#/components/schemas/TypedProperties/properties/enabled",
-            "#/paths/~1typed/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/TypedProperties/properties/enabled",
+                    "#/paths/~1typed/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/TypedProperties/properties/enabled",
+                    "#/paths/~1typed/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/TypedProperties/properties/enabled",
-            "#/paths/~1typed/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema metadata changed",
+                class: Trivial,
+                details: Metadata,
+            },
         ],
-        comparison: Output,
-        class: Trivial,
-        details: Metadata,
     },
 ]
diff --git a/tests/cases/simple/output/boolean-enum-change.out b/tests/cases/simple/output/boolean-enum-change.out
index 670c172..37bf0eb 100644
--- a/tests/cases/simple/output/boolean-enum-change.out
+++ b/tests/cases/simple/output/boolean-enum-change.out
@@ -1,6 +1,6 @@
 --- boolean-enum-change.json
 +++ patched
-@@ -159,6 +159,9 @@
+@@
              "type": "integer"
            },
            "enabled": {
@@ -15,17 +15,27 @@
 Result for patch:
 [
     Change {
-        message: "boolean schema changed",
-        old_path: [
-            "#/components/schemas/TypedProperties/properties/enabled",
-            "#/paths/~1typed/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/TypedProperties/properties/enabled",
+                    "#/paths/~1typed/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/TypedProperties/properties/enabled",
+                    "#/paths/~1typed/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/TypedProperties/properties/enabled",
-            "#/paths/~1typed/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "boolean schema changed",
+                class: Unhandled,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Unhandled,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/change-default-response.out b/tests/cases/simple/output/change-default-response.out
index 51a21da..c72f9ca 100644
--- a/tests/cases/simple/output/change-default-response.out
+++ b/tests/cases/simple/output/change-default-response.out
@@ -1,6 +1,6 @@
 --- change-default-response.json
 +++ patched
-@@ -451,7 +451,7 @@
+@@
                  }
                }
              },
diff --git a/tests/cases/simple/output/change-header-parameter.out b/tests/cases/simple/output/change-header-parameter.out
index 8b8fec2..b506dce 100644
--- a/tests/cases/simple/output/change-header-parameter.out
+++ b/tests/cases/simple/output/change-header-parameter.out
@@ -1,6 +1,6 @@
 --- change-header-parameter.json
 +++ patched
-@@ -466,7 +466,7 @@
+@@
              "name": "X-Request-Id",
              "required": true,
              "schema": {
@@ -14,15 +14,25 @@
 Result for patch:
 [
     Change {
-        message: "schema types changed",
-        old_path: [
-            "#/paths/~1with-header/get/parameters/0/schema",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1with-header/get/parameters/0/schema",
+                ],
+                new: [
+                    "#/paths/~1with-header/get/parameters/0/schema",
+                ],
+                comparison: Input,
+            },
         ],
-        new_path: [
-            "#/paths/~1with-header/get/parameters/0/schema",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema types changed",
+                class: Incompatible,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Input,
-        class: Incompatible,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/change-operation-parameter-requirement.out b/tests/cases/simple/output/change-operation-parameter-requirement.out
index dccb0ce..974f59a 100644
--- a/tests/cases/simple/output/change-operation-parameter-requirement.out
+++ b/tests/cases/simple/output/change-operation-parameter-requirement.out
@@ -1,6 +1,6 @@
 --- change-operation-parameter-requirement.json
 +++ patched
-@@ -253,7 +253,7 @@
+@@
              "description": "Language for the greeting",
              "in": "query",
              "name": "language",
@@ -14,15 +14,25 @@
 Result for patch:
 [
     Change {
-        message: "The parameter 'language' was optional and is now required",
-        old_path: [
-            "#/paths/~1hello~1{name}/get/parameters/1",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1hello~1{name}/get/parameters/1",
+                ],
+                new: [
+                    "#/paths/~1hello~1{name}/get/parameters/1",
+                ],
+                comparison: Input,
+            },
         ],
-        new_path: [
-            "#/paths/~1hello~1{name}/get/parameters/1",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "The parameter 'language' was optional and is now required",
+                class: BackwardIncompatible,
+                details: MoreStrict,
+            },
         ],
-        comparison: Input,
-        class: BackwardIncompatible,
-        details: MoreStrict,
     },
 ]
diff --git a/tests/cases/simple/output/change-operation-parameter-type.out b/tests/cases/simple/output/change-operation-parameter-type.out
index 1a21afd..9252a75 100644
--- a/tests/cases/simple/output/change-operation-parameter-type.out
+++ b/tests/cases/simple/output/change-operation-parameter-type.out
@@ -1,6 +1,6 @@
 --- change-operation-parameter-type.json
 +++ patched
-@@ -255,7 +255,7 @@
+@@
              "name": "language",
              "required": false,
              "schema": {
@@ -14,15 +14,25 @@
 Result for patch:
 [
     Change {
-        message: "schema types changed",
-        old_path: [
-            "#/paths/~1hello~1{name}/get/parameters/1/schema",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1hello~1{name}/get/parameters/1/schema",
+                ],
+                new: [
+                    "#/paths/~1hello~1{name}/get/parameters/1/schema",
+                ],
+                comparison: Input,
+            },
         ],
-        new_path: [
-            "#/paths/~1hello~1{name}/get/parameters/1/schema",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema types changed",
+                class: Incompatible,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Input,
-        class: Incompatible,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/change-property-type.out b/tests/cases/simple/output/change-property-type.out
index 59b6235..0084054 100644
--- a/tests/cases/simple/output/change-property-type.out
+++ b/tests/cases/simple/output/change-property-type.out
@@ -1,6 +1,6 @@
 --- change-property-type.json
 +++ patched
-@@ -50,7 +50,7 @@
+@@
          "properties": {
            "message": {
              "description": "The greeting message",
@@ -14,17 +14,27 @@
 Result for patch:
 [
     Change {
-        message: "schema types changed",
-        old_path: [
-            "#/components/schemas/GreetingResponse/properties/message",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/GreetingResponse/properties/message",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponse/properties/message",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponse/properties/message",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema types changed",
+                class: Incompatible,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Incompatible,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/inline-to-allof.out b/tests/cases/simple/output/inline-to-allof.out
index 5173ba2..954ca32 100644
--- a/tests/cases/simple/output/inline-to-allof.out
+++ b/tests/cases/simple/output/inline-to-allof.out
@@ -1,6 +1,6 @@
 --- inline-to-allof.json
 +++ patched
-@@ -246,7 +246,12 @@
+@@
              "in": "path",
              "name": "name",
              "schema": {
@@ -19,15 +19,25 @@
 Result for patch:
 [
     Change {
-        message: "schema metadata added",
-        old_path: [
-            "#/paths/~1hello~1{name}/get/parameters/0/schema",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1hello~1{name}/get/parameters/0/schema",
+                ],
+                new: [
+                    "#/paths/~1hello~1{name}/get/parameters/0/schema",
+                ],
+                comparison: Input,
+            },
         ],
-        new_path: [
-            "#/paths/~1hello~1{name}/get/parameters/0/schema",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema metadata added",
+                class: Trivial,
+                details: Metadata,
+            },
         ],
-        comparison: Input,
-        class: Trivial,
-        details: Metadata,
     },
 ]
diff --git a/tests/cases/simple/output/integer-format-change.out b/tests/cases/simple/output/integer-format-change.out
index f97a7a4..14535bd 100644
--- a/tests/cases/simple/output/integer-format-change.out
+++ b/tests/cases/simple/output/integer-format-change.out
@@ -1,6 +1,6 @@
 --- integer-format-change.json
 +++ patched
-@@ -156,6 +156,7 @@
+@@
        "TypedProperties": {
          "properties": {
            "count": {
@@ -13,17 +13,27 @@
 Result for patch:
 [
     Change {
-        message: "integer schema changed",
-        old_path: [
-            "#/components/schemas/TypedProperties/properties/count",
-            "#/paths/~1typed/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/TypedProperties/properties/count",
+                    "#/paths/~1typed/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/TypedProperties/properties/count",
+                    "#/paths/~1typed/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/TypedProperties/properties/count",
-            "#/paths/~1typed/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "integer schema changed",
+                class: Unhandled,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Unhandled,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/modify-cycle-type.out b/tests/cases/simple/output/modify-cycle-type.out
index 4dd795b..6fb2fa4 100644
--- a/tests/cases/simple/output/modify-cycle-type.out
+++ b/tests/cases/simple/output/modify-cycle-type.out
@@ -1,6 +1,6 @@
 --- modify-cycle-type.json
 +++ patched
-@@ -145,10 +145,7 @@
+@@
        "Tree": {
          "properties": {
            "children": {
@@ -17,18 +17,28 @@
 Result for patch:
 [
     Change {
-        message: "schema types changed",
-        old_path: [
-            "#/components/schemas/Tree/properties/children",
-            "#/paths/~1tree/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/Tree/properties/children",
+                    "#/paths/~1tree/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/Tree",
+                    "#/components/schemas/Tree/properties/children/$ref",
+                    "#/paths/~1tree/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/Tree",
-            "#/components/schemas/Tree/properties/children/$ref",
-            "#/paths/~1tree/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema types changed",
+                class: Incompatible,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Incompatible,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/multi-allof-variant-change.out b/tests/cases/simple/output/multi-allof-variant-change.out
index b2c82ec..b50e58b 100644
--- a/tests/cases/simple/output/multi-allof-variant-change.out
+++ b/tests/cases/simple/output/multi-allof-variant-change.out
@@ -1,6 +1,6 @@
 --- multi-allof-variant-change.json
 +++ patched
-@@ -95,7 +95,7 @@
+@@
            {
              "properties": {
                "id": {
@@ -14,17 +14,27 @@
 Result for patch:
 [
     Change {
-        message: "unhandled, 'allOf' schema",
-        old_path: [
-            "#/components/schemas/MultiAllOf/allOf",
-            "#/paths/~1allof/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/MultiAllOf/allOf",
+                    "#/paths/~1allof/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/MultiAllOf/allOf",
+                    "#/paths/~1allof/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/MultiAllOf/allOf",
-            "#/paths/~1allof/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "unhandled, 'allOf' schema",
+                class: Unhandled,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Unhandled,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/multi-anyof-variant-change.out b/tests/cases/simple/output/multi-anyof-variant-change.out
index fc70f50..f82c97e 100644
--- a/tests/cases/simple/output/multi-anyof-variant-change.out
+++ b/tests/cases/simple/output/multi-anyof-variant-change.out
@@ -1,6 +1,6 @@
 --- multi-anyof-variant-change.json
 +++ patched
-@@ -4,7 +4,7 @@
+@@
        "AnyOfExample": {
          "anyOf": [
            {
@@ -14,17 +14,27 @@
 Result for patch:
 [
     Change {
-        message: "unhandled, 'anyOf' schema",
-        old_path: [
-            "#/components/schemas/AnyOfExample",
-            "#/paths/~1anyof/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/AnyOfExample",
+                    "#/paths/~1anyof/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/AnyOfExample",
+                    "#/paths/~1anyof/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/AnyOfExample",
-            "#/paths/~1anyof/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "unhandled, 'anyOf' schema",
+                class: Unhandled,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Unhandled,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/multi-oneof-count-change.out b/tests/cases/simple/output/multi-oneof-count-change.out
index 8d054d6..94ebd88 100644
--- a/tests/cases/simple/output/multi-oneof-count-change.out
+++ b/tests/cases/simple/output/multi-oneof-count-change.out
@@ -1,6 +1,6 @@
 --- multi-oneof-count-change.json
 +++ patched
-@@ -117,6 +117,9 @@
+@@
            },
            {
              "type": "integer"
@@ -15,17 +15,27 @@
 Result for patch:
 [
     Change {
-        message: "oneOf schema count changed",
-        old_path: [
-            "#/components/schemas/MultiOneOf/oneOf",
-            "#/paths/~1oneof/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/MultiOneOf/oneOf",
+                    "#/paths/~1oneof/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/MultiOneOf/oneOf",
+                    "#/paths/~1oneof/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/MultiOneOf/oneOf",
-            "#/paths/~1oneof/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "oneOf schema count changed",
+                class: Unhandled,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Unhandled,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/multi-oneof-variant-change.out b/tests/cases/simple/output/multi-oneof-variant-change.out
index 9e67399..95ffac8 100644
--- a/tests/cases/simple/output/multi-oneof-variant-change.out
+++ b/tests/cases/simple/output/multi-oneof-variant-change.out
@@ -1,6 +1,6 @@
 --- multi-oneof-variant-change.json
 +++ patched
-@@ -113,7 +113,7 @@
+@@
        "MultiOneOf": {
          "oneOf": [
            {
@@ -14,17 +14,27 @@
 Result for patch:
 [
     Change {
-        message: "schema types changed",
-        old_path: [
-            "#/components/schemas/MultiOneOf/oneOf/0",
-            "#/paths/~1oneof/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/MultiOneOf/oneOf/0",
+                    "#/paths/~1oneof/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/MultiOneOf/oneOf/0",
+                    "#/paths/~1oneof/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/MultiOneOf/oneOf/0",
-            "#/paths/~1oneof/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema types changed",
+                class: Incompatible,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Incompatible,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/not-inner-to-allof.out b/tests/cases/simple/output/not-inner-to-allof.out
index c3c4808..47df17f 100644
--- a/tests/cases/simple/output/not-inner-to-allof.out
+++ b/tests/cases/simple/output/not-inner-to-allof.out
@@ -1,6 +1,6 @@
 --- not-inner-to-allof.json
 +++ patched
-@@ -54,7 +54,12 @@
+@@
            },
            "not_a_number": {
              "not": {
@@ -19,17 +19,27 @@
 Result for patch:
 [
     Change {
-        message: "schema metadata added",
-        old_path: [
-            "#/components/schemas/GreetingResponse/properties/not_a_number/not",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/GreetingResponse/properties/not_a_number/not",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponse/properties/not_a_number/not",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponse/properties/not_a_number/not",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema metadata added",
+                class: Trivial,
+                details: Metadata,
+            },
         ],
-        comparison: Output,
-        class: Trivial,
-        details: Metadata,
     },
 ]
diff --git a/tests/cases/simple/output/not-to-allof.out b/tests/cases/simple/output/not-to-allof.out
index b3ef213..4af3db6 100644
--- a/tests/cases/simple/output/not-to-allof.out
+++ b/tests/cases/simple/output/not-to-allof.out
@@ -1,6 +1,6 @@
 --- not-to-allof.json
 +++ patched
-@@ -53,9 +53,14 @@
+@@
              "type": "string"
            },
            "not_a_number": {
@@ -23,17 +23,27 @@
 Result for patch:
 [
     Change {
-        message: "schema metadata added",
-        old_path: [
-            "#/components/schemas/GreetingResponse/properties/not_a_number",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/GreetingResponse/properties/not_a_number",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponse/properties/not_a_number",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponse/properties/not_a_number",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema metadata added",
+                class: Trivial,
+                details: Metadata,
+            },
         ],
-        comparison: Output,
-        class: Trivial,
-        details: Metadata,
     },
 ]
diff --git a/tests/cases/simple/output/number-constraints-change.out b/tests/cases/simple/output/number-constraints-change.out
index 241849d..5754482 100644
--- a/tests/cases/simple/output/number-constraints-change.out
+++ b/tests/cases/simple/output/number-constraints-change.out
@@ -1,6 +1,6 @@
 --- number-constraints-change.json
 +++ patched
-@@ -162,6 +162,7 @@
+@@
              "type": "boolean"
            },
            "ratio": {
@@ -13,17 +13,27 @@
 Result for patch:
 [
     Change {
-        message: "number schema changed",
-        old_path: [
-            "#/components/schemas/TypedProperties/properties/ratio",
-            "#/paths/~1typed/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/TypedProperties/properties/ratio",
+                    "#/paths/~1typed/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/TypedProperties/properties/ratio",
+                    "#/paths/~1typed/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/TypedProperties/properties/ratio",
-            "#/paths/~1typed/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "number schema changed",
+                class: Unhandled,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Unhandled,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/object-additional-props-false.out b/tests/cases/simple/output/object-additional-props-false.out
index 7eb6590..5535517 100644
--- a/tests/cases/simple/output/object-additional-props-false.out
+++ b/tests/cases/simple/output/object-additional-props-false.out
@@ -1,6 +1,6 @@
 --- object-additional-props-false.json
 +++ patched
-@@ -121,9 +121,7 @@
+@@
          ]
        },
        "ObjectWithConstraints": {
@@ -16,17 +16,27 @@
 Result for patch:
 [
     Change {
-        message: "object additionalProperties changed",
-        old_path: [
-            "#/components/schemas/ObjectWithConstraints",
-            "#/paths/~1objects/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/ObjectWithConstraints",
+                    "#/paths/~1objects/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/ObjectWithConstraints",
+                    "#/paths/~1objects/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/ObjectWithConstraints",
-            "#/paths/~1objects/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "object additionalProperties changed",
+                class: Unhandled,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Unhandled,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/object-additional-props-schema-change.out b/tests/cases/simple/output/object-additional-props-schema-change.out
index e702620..3248286 100644
--- a/tests/cases/simple/output/object-additional-props-schema-change.out
+++ b/tests/cases/simple/output/object-additional-props-schema-change.out
@@ -1,6 +1,6 @@
 --- object-additional-props-schema-change.json
 +++ patched
-@@ -122,7 +122,7 @@
+@@
        },
        "ObjectWithConstraints": {
          "additionalProperties": {
@@ -14,17 +14,27 @@
 Result for patch:
 [
     Change {
-        message: "schema types changed",
-        old_path: [
-            "#/components/schemas/ObjectWithConstraints/additionalProperties",
-            "#/paths/~1objects/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/ObjectWithConstraints/additionalProperties",
+                    "#/paths/~1objects/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/ObjectWithConstraints/additionalProperties",
+                    "#/paths/~1objects/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/ObjectWithConstraints/additionalProperties",
-            "#/paths/~1objects/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema types changed",
+                class: Incompatible,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Incompatible,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/object-additional-props-type-change.out b/tests/cases/simple/output/object-additional-props-type-change.out
index dd355d5..1bbc3f2 100644
--- a/tests/cases/simple/output/object-additional-props-type-change.out
+++ b/tests/cases/simple/output/object-additional-props-type-change.out
@@ -1,6 +1,6 @@
 --- object-additional-props-type-change.json
 +++ patched
-@@ -121,9 +121,7 @@
+@@
          ]
        },
        "ObjectWithConstraints": {
@@ -16,17 +16,27 @@
 Result for patch:
 [
     Change {
-        message: "object additionalProperties changed",
-        old_path: [
-            "#/components/schemas/ObjectWithConstraints",
-            "#/paths/~1objects/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/ObjectWithConstraints",
+                    "#/paths/~1objects/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/ObjectWithConstraints",
+                    "#/paths/~1objects/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/ObjectWithConstraints",
-            "#/paths/~1objects/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "object additionalProperties changed",
+                class: Unhandled,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Unhandled,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/object-max-properties-change.out b/tests/cases/simple/output/object-max-properties-change.out
index c519851..53110fc 100644
--- a/tests/cases/simple/output/object-max-properties-change.out
+++ b/tests/cases/simple/output/object-max-properties-change.out
@@ -1,6 +1,6 @@
 --- object-max-properties-change.json
 +++ patched
-@@ -124,7 +124,7 @@
+@@
          "additionalProperties": {
            "type": "string"
          },
@@ -14,17 +14,27 @@
 Result for patch:
 [
     Change {
-        message: "object maxProperties changed",
-        old_path: [
-            "#/components/schemas/ObjectWithConstraints",
-            "#/paths/~1objects/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/ObjectWithConstraints",
+                    "#/paths/~1objects/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/ObjectWithConstraints",
+                    "#/paths/~1objects/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/ObjectWithConstraints",
-            "#/paths/~1objects/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "object maxProperties changed",
+                class: Unhandled,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Unhandled,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/object-min-properties-change.out b/tests/cases/simple/output/object-min-properties-change.out
index cc5eca9..067d2c9 100644
--- a/tests/cases/simple/output/object-min-properties-change.out
+++ b/tests/cases/simple/output/object-min-properties-change.out
@@ -1,6 +1,6 @@
 --- object-min-properties-change.json
 +++ patched
-@@ -125,7 +125,7 @@
+@@
            "type": "string"
          },
          "maxProperties": 5,
@@ -14,17 +14,27 @@
 Result for patch:
 [
     Change {
-        message: "object minProperties changed",
-        old_path: [
-            "#/components/schemas/ObjectWithConstraints",
-            "#/paths/~1objects/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/ObjectWithConstraints",
+                    "#/paths/~1objects/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/ObjectWithConstraints",
+                    "#/paths/~1objects/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/ObjectWithConstraints",
-            "#/paths/~1objects/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "object minProperties changed",
+                class: Unhandled,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Unhandled,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/oneof-to-allof.out b/tests/cases/simple/output/oneof-to-allof.out
index 78d37b8..99afdd7 100644
--- a/tests/cases/simple/output/oneof-to-allof.out
+++ b/tests/cases/simple/output/oneof-to-allof.out
@@ -1,6 +1,6 @@
 --- oneof-to-allof.json
 +++ patched
-@@ -74,12 +74,12 @@
+@@
              "description": "Via anyOf."
            },
            "via_oneof": {
@@ -21,17 +21,27 @@
 Result for patch:
 [
     Change {
-        message: "schema metadata changed",
-        old_path: [
-            "#/components/schemas/GreetingResponse/properties/via_oneof",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/GreetingResponse/properties/via_oneof",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponse/properties/via_oneof",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponse/properties/via_oneof",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema metadata changed",
+                class: Trivial,
+                details: Metadata,
+            },
         ],
-        comparison: Output,
-        class: Trivial,
-        details: Metadata,
     },
 ]
diff --git a/tests/cases/simple/output/oneof-to-anyof.out b/tests/cases/simple/output/oneof-to-anyof.out
index c643d8b..c042ab0 100644
--- a/tests/cases/simple/output/oneof-to-anyof.out
+++ b/tests/cases/simple/output/oneof-to-anyof.out
@@ -1,6 +1,6 @@
 --- oneof-to-anyof.json
 +++ patched
-@@ -74,12 +74,12 @@
+@@
              "description": "Via anyOf."
            },
            "via_oneof": {
@@ -21,17 +21,27 @@
 Result for patch:
 [
     Change {
-        message: "schema metadata changed",
-        old_path: [
-            "#/components/schemas/GreetingResponse/properties/via_oneof",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/GreetingResponse/properties/via_oneof",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponse/properties/via_oneof",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponse/properties/via_oneof",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema metadata changed",
+                class: Trivial,
+                details: Metadata,
+            },
         ],
-        comparison: Output,
-        class: Trivial,
-        details: Metadata,
     },
 ]
diff --git a/tests/cases/simple/output/oneof-to-ref.out b/tests/cases/simple/output/oneof-to-ref.out
index 0ec92a5..5ad1463 100644
--- a/tests/cases/simple/output/oneof-to-ref.out
+++ b/tests/cases/simple/output/oneof-to-ref.out
@@ -1,6 +1,6 @@
 --- oneof-to-ref.json
 +++ patched
-@@ -74,12 +74,7 @@
+@@
              "description": "Via anyOf."
            },
            "via_oneof": {
@@ -19,17 +19,27 @@
 Result for patch:
 [
     Change {
-        message: "schema metadata removed",
-        old_path: [
-            "#/components/schemas/GreetingResponse/properties/via_oneof",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/GreetingResponse/properties/via_oneof",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponse/properties/via_oneof",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponse/properties/via_oneof",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema metadata removed",
+                class: Trivial,
+                details: Metadata,
+            },
         ],
-        comparison: Output,
-        class: Trivial,
-        details: Metadata,
     },
 ]
diff --git a/tests/cases/simple/output/param-required-to-optional.out b/tests/cases/simple/output/param-required-to-optional.out
index c955a3c..1419a39 100644
--- a/tests/cases/simple/output/param-required-to-optional.out
+++ b/tests/cases/simple/output/param-required-to-optional.out
@@ -1,6 +1,6 @@
 --- param-required-to-optional.json
 +++ patched
-@@ -464,7 +464,7 @@
+@@
            {
              "in": "header",
              "name": "X-Request-Id",
@@ -14,15 +14,25 @@
 Result for patch:
 [
     Change {
-        message: "The parameter 'X-Request-Id' was required and is now optional",
-        old_path: [
-            "#/paths/~1with-header/get/parameters/0",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1with-header/get/parameters/0",
+                ],
+                new: [
+                    "#/paths/~1with-header/get/parameters/0",
+                ],
+                comparison: Input,
+            },
         ],
-        new_path: [
-            "#/paths/~1with-header/get/parameters/0",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "The parameter 'X-Request-Id' was required and is now optional",
+                class: ForwardIncompatible,
+                details: LessStrict,
+            },
         ],
-        comparison: Input,
-        class: ForwardIncompatible,
-        details: LessStrict,
     },
 ]
diff --git a/tests/cases/simple/output/param-schema-to-content.out b/tests/cases/simple/output/param-schema-to-content.out
index b9f44c6..2ff8551 100644
--- a/tests/cases/simple/output/param-schema-to-content.out
+++ b/tests/cases/simple/output/param-schema-to-content.out
@@ -1,6 +1,6 @@
 --- param-schema-to-content.json
 +++ patched
-@@ -250,13 +250,17 @@
+@@
              }
            },
            {
@@ -27,15 +27,25 @@
 Result for patch:
 [
     Change {
-        message: "Unhandled change to parameter schema or content",
-        old_path: [
-            "#/paths/~1hello~1{name}/get/parameters/1",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1hello~1{name}/get/parameters/1",
+                ],
+                new: [
+                    "#/paths/~1hello~1{name}/get/parameters/1",
+                ],
+                comparison: Input,
+            },
         ],
-        new_path: [
-            "#/paths/~1hello~1{name}/get/parameters/1",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "Unhandled change to parameter schema or content",
+                class: Unhandled,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Input,
-        class: Unhandled,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/ref-chain-change.out b/tests/cases/simple/output/ref-chain-change.out
index 9d3bca3..939c83e 100644
--- a/tests/cases/simple/output/ref-chain-change.out
+++ b/tests/cases/simple/output/ref-chain-change.out
@@ -1,6 +1,6 @@
 --- ref-chain-change.json
 +++ patched
-@@ -132,7 +132,7 @@
+@@
          "$ref": "#/components/schemas/RefChainB"
        },
        "RefChainB": {
@@ -14,39 +14,59 @@
 Result for patch:
 [
     Change {
-        message: "object required properties changed",
-        old_path: [
-            "#/components/schemas/SubType",
-            "#/components/schemas/RefChainB/$ref",
-            "#/components/schemas/RefChainA/$ref",
-            "#/paths/~1refs/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/SubType",
+                    "#/components/schemas/RefChainB/$ref",
+                    "#/components/schemas/RefChainA/$ref",
+                    "#/paths/~1refs/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/ErrorResponse",
+                    "#/components/schemas/RefChainB/$ref",
+                    "#/components/schemas/RefChainA/$ref",
+                    "#/paths/~1refs/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/ErrorResponse",
-            "#/components/schemas/RefChainB/$ref",
-            "#/components/schemas/RefChainA/$ref",
-            "#/paths/~1refs/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "object required properties changed",
+                class: Unhandled,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Unhandled,
-        details: UnknownDifference,
     },
     Change {
-        message: "object properties changed",
-        old_path: [
-            "#/components/schemas/SubType",
-            "#/components/schemas/RefChainB/$ref",
-            "#/components/schemas/RefChainA/$ref",
-            "#/paths/~1refs/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/SubType",
+                    "#/components/schemas/RefChainB/$ref",
+                    "#/components/schemas/RefChainA/$ref",
+                    "#/paths/~1refs/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/ErrorResponse",
+                    "#/components/schemas/RefChainB/$ref",
+                    "#/components/schemas/RefChainA/$ref",
+                    "#/paths/~1refs/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/ErrorResponse",
-            "#/components/schemas/RefChainB/$ref",
-            "#/components/schemas/RefChainA/$ref",
-            "#/paths/~1refs/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "object properties changed",
+                class: Unhandled,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Unhandled,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/ref-to-allof.out b/tests/cases/simple/output/ref-to-allof.out
index 0ffecab..3316bd2 100644
--- a/tests/cases/simple/output/ref-to-allof.out
+++ b/tests/cases/simple/output/ref-to-allof.out
@@ -1,6 +1,6 @@
 --- ref-to-allof.json
 +++ patched
-@@ -82,7 +82,12 @@
+@@
              ]
            },
            "via_ref": {
@@ -19,17 +19,27 @@
 Result for patch:
 [
     Change {
-        message: "schema metadata added",
-        old_path: [
-            "#/components/schemas/GreetingResponse/properties/via_ref",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/GreetingResponse/properties/via_ref",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponse/properties/via_ref",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponse/properties/via_ref",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema metadata added",
+                class: Trivial,
+                details: Metadata,
+            },
         ],
-        comparison: Output,
-        class: Trivial,
-        details: Metadata,
     },
 ]
diff --git a/tests/cases/simple/output/ref-to-anyof.out b/tests/cases/simple/output/ref-to-anyof.out
index f764670..3349ae3 100644
--- a/tests/cases/simple/output/ref-to-anyof.out
+++ b/tests/cases/simple/output/ref-to-anyof.out
@@ -1,6 +1,6 @@
 --- ref-to-anyof.json
 +++ patched
-@@ -82,7 +82,12 @@
+@@
              ]
            },
            "via_ref": {
@@ -19,17 +19,27 @@
 Result for patch:
 [
     Change {
-        message: "schema metadata added",
-        old_path: [
-            "#/components/schemas/GreetingResponse/properties/via_ref",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/GreetingResponse/properties/via_ref",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponse/properties/via_ref",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponse/properties/via_ref",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema metadata added",
+                class: Trivial,
+                details: Metadata,
+            },
         ],
-        comparison: Output,
-        class: Trivial,
-        details: Metadata,
     },
 ]
diff --git a/tests/cases/simple/output/ref-to-inline-allof.out b/tests/cases/simple/output/ref-to-inline-allof.out
index 41f89a9..311ff4e 100644
--- a/tests/cases/simple/output/ref-to-inline-allof.out
+++ b/tests/cases/simple/output/ref-to-inline-allof.out
@@ -1,6 +1,6 @@
 --- ref-to-inline-allof.json
 +++ patched
-@@ -82,7 +82,18 @@
+@@
              ]
            },
            "via_ref": {
@@ -25,32 +25,52 @@
 Result for patch:
 [
     Change {
-        message: "schema metadata added",
-        old_path: [
-            "#/components/schemas/GreetingResponse/properties/via_ref",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/GreetingResponse/properties/via_ref",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponse/properties/via_ref",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponse/properties/via_ref",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema metadata added",
+                class: Trivial,
+                details: Metadata,
+            },
         ],
-        comparison: Output,
-        class: Trivial,
-        details: Metadata,
     },
     Change {
-        message: "schema metadata changed",
-        old_path: [
-            "#/components/schemas/SubType",
-            "#/components/schemas/GreetingResponse/properties/via_ref/$ref",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/SubType",
+                    "#/components/schemas/GreetingResponse/properties/via_ref/$ref",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponse/properties/via_ref/0",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponse/properties/via_ref/0",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema metadata changed",
+                class: Trivial,
+                details: Metadata,
+            },
         ],
-        comparison: Output,
-        class: Trivial,
-        details: Metadata,
     },
 ]
diff --git a/tests/cases/simple/output/ref-to-oneof.out b/tests/cases/simple/output/ref-to-oneof.out
index 4f95563..7224c41 100644
--- a/tests/cases/simple/output/ref-to-oneof.out
+++ b/tests/cases/simple/output/ref-to-oneof.out
@@ -1,6 +1,6 @@
 --- ref-to-oneof.json
 +++ patched
-@@ -82,7 +82,12 @@
+@@
              ]
            },
            "via_ref": {
@@ -19,17 +19,27 @@
 Result for patch:
 [
     Change {
-        message: "schema metadata added",
-        old_path: [
-            "#/components/schemas/GreetingResponse/properties/via_ref",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/GreetingResponse/properties/via_ref",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponse/properties/via_ref",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponse/properties/via_ref",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema metadata added",
+                class: Trivial,
+                details: Metadata,
+            },
         ],
-        comparison: Output,
-        class: Trivial,
-        details: Metadata,
     },
 ]
diff --git a/tests/cases/simple/output/remove-default-response.out b/tests/cases/simple/output/remove-default-response.out
index 615e057..98047b6 100644
--- a/tests/cases/simple/output/remove-default-response.out
+++ b/tests/cases/simple/output/remove-default-response.out
@@ -1,6 +1,6 @@
 --- remove-default-response.json
 +++ patched
-@@ -442,16 +442,6 @@
+@@
          "responses": {
            "200": {
              "description": "Success"
@@ -22,15 +22,25 @@
 Result for patch:
 [
     Change {
-        message: "operation removed a default response",
-        old_path: [
-            "#/paths/~1with-default/get",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1with-default/get",
+                ],
+                new: [
+                    "#/paths/~1with-default/get",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/paths/~1with-default/get",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "operation removed a default response",
+                class: Unhandled,
+                details: Removed,
+            },
         ],
-        comparison: Output,
-        class: Unhandled,
-        details: Removed,
     },
 ]
diff --git a/tests/cases/simple/output/remove-header-parameter.out b/tests/cases/simple/output/remove-header-parameter.out
index 3f5b122..ce18379 100644
--- a/tests/cases/simple/output/remove-header-parameter.out
+++ b/tests/cases/simple/output/remove-header-parameter.out
@@ -1,6 +1,6 @@
 --- remove-header-parameter.json
 +++ patched
-@@ -462,14 +462,6 @@
+@@
          "operationId": "with_header",
          "parameters": [
            {
@@ -20,15 +20,25 @@
 Result for patch:
 [
     Change {
-        message: "The parameter 'X-Request-Id' was removed",
-        old_path: [
-            "#/paths/~1with-header/get/parameters/0",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1with-header/get/parameters/0",
+                ],
+                new: [
+                    "#/paths/~1with-header/get",
+                ],
+                comparison: Input,
+            },
         ],
-        new_path: [
-            "#/paths/~1with-header/get",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "The parameter 'X-Request-Id' was removed",
+                class: BackwardIncompatible,
+                details: Removed,
+            },
         ],
-        comparison: Input,
-        class: BackwardIncompatible,
-        details: Removed,
     },
 ]
diff --git a/tests/cases/simple/output/remove-operation-parameter.out b/tests/cases/simple/output/remove-operation-parameter.out
index 7fc3327..b539ab5 100644
--- a/tests/cases/simple/output/remove-operation-parameter.out
+++ b/tests/cases/simple/output/remove-operation-parameter.out
@@ -1,6 +1,6 @@
 --- remove-operation-parameter.json
 +++ patched
-@@ -248,15 +248,6 @@
+@@
              "schema": {
                "type": "string"
              }
@@ -21,15 +21,25 @@
 Result for patch:
 [
     Change {
-        message: "The parameter 'language' was removed",
-        old_path: [
-            "#/paths/~1hello~1{name}/get/parameters/1",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1hello~1{name}/get/parameters/1",
+                ],
+                new: [
+                    "#/paths/~1hello~1{name}/get",
+                ],
+                comparison: Input,
+            },
         ],
-        new_path: [
-            "#/paths/~1hello~1{name}/get",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "The parameter 'language' was removed",
+                class: BackwardIncompatible,
+                details: Removed,
+            },
         ],
-        comparison: Input,
-        class: BackwardIncompatible,
-        details: Removed,
     },
 ]
diff --git a/tests/cases/simple/output/remove-operation.out b/tests/cases/simple/output/remove-operation.out
index 04ed3a9..e2cf632 100644
--- a/tests/cases/simple/output/remove-operation.out
+++ b/tests/cases/simple/output/remove-operation.out
@@ -1,6 +1,6 @@
 --- remove-operation.json
 +++ patched
-@@ -361,18 +361,7 @@
+@@
          "summary": "Get oneOf schema"
        }
      },
@@ -25,15 +25,25 @@
 Result for patch:
 [
     Change {
-        message: "The operation ping was removed",
-        old_path: [
-            "#/paths/~1ping/get",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1ping/get",
+                ],
+                new: [
+                    "#/paths",
+                ],
+                comparison: Structural,
+            },
         ],
-        new_path: [
-            "#/paths",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "The operation ping was removed",
+                class: BackwardIncompatible,
+                details: Removed,
+            },
         ],
-        comparison: Structural,
-        class: BackwardIncompatible,
-        details: Removed,
     },
 ]
diff --git a/tests/cases/simple/output/remove-optional-body.out b/tests/cases/simple/output/remove-optional-body.out
index 4a7a983..4f88a2a 100644
--- a/tests/cases/simple/output/remove-optional-body.out
+++ b/tests/cases/simple/output/remove-optional-body.out
@@ -1,6 +1,6 @@
 --- remove-optional-body.json
 +++ patched
-@@ -296,16 +296,6 @@
+@@
        },
        "put": {
          "operationId": "update_item",
@@ -22,15 +22,25 @@
 Result for patch:
 [
     Change {
-        message: "an optional body parameter was removed",
-        old_path: [
-            "#/paths/~1items/put",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1items/put",
+                ],
+                new: [
+                    "#/paths/~1items/put",
+                ],
+                comparison: Input,
+            },
         ],
-        new_path: [
-            "#/paths/~1items/put",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "an optional body parameter was removed",
+                class: ForwardIncompatible,
+                details: Removed,
+            },
         ],
-        comparison: Input,
-        class: ForwardIncompatible,
-        details: Removed,
     },
 ]
diff --git a/tests/cases/simple/output/remove-required-body.out b/tests/cases/simple/output/remove-required-body.out
index 8cb5edc..e7919bb 100644
--- a/tests/cases/simple/output/remove-required-body.out
+++ b/tests/cases/simple/output/remove-required-body.out
@@ -1,6 +1,6 @@
 --- remove-required-body.json
 +++ patched
-@@ -277,16 +277,6 @@
+@@
      "/items": {
        "post": {
          "operationId": "create_item",
@@ -22,15 +22,25 @@
 Result for patch:
 [
     Change {
-        message: "a required body parameter was removed",
-        old_path: [
-            "#/paths/~1items/post",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1items/post",
+                ],
+                new: [
+                    "#/paths/~1items/post",
+                ],
+                comparison: Input,
+            },
         ],
-        new_path: [
-            "#/paths/~1items/post",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "a required body parameter was removed",
+                class: ForwardIncompatible,
+                details: Removed,
+            },
         ],
-        comparison: Input,
-        class: ForwardIncompatible,
-        details: Removed,
     },
 ]
diff --git a/tests/cases/simple/output/remove-response-code.out b/tests/cases/simple/output/remove-response-code.out
index 6decf76..ea17cf9 100644
--- a/tests/cases/simple/output/remove-response-code.out
+++ b/tests/cases/simple/output/remove-response-code.out
@@ -1,6 +1,6 @@
 --- remove-response-code.json
 +++ patched
-@@ -440,9 +440,6 @@
+@@
        "get": {
          "operationId": "with_default",
          "responses": {
@@ -15,15 +15,25 @@
 Result for patch:
 [
     Change {
-        message: "operation no longer responds with status 200",
-        old_path: [
-            "#/paths/~1with-default/get",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1with-default/get",
+                ],
+                new: [
+                    "#/paths/~1with-default/get",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/paths/~1with-default/get",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "operation no longer responds with status 200",
+                class: ForwardIncompatible,
+                details: Removed,
+            },
         ],
-        comparison: Output,
-        class: ForwardIncompatible,
-        details: Removed,
     },
 ]
diff --git a/tests/cases/simple/output/remove-unnamed-operation.out b/tests/cases/simple/output/remove-unnamed-operation.out
index a895a32..61326da 100644
--- a/tests/cases/simple/output/remove-unnamed-operation.out
+++ b/tests/cases/simple/output/remove-unnamed-operation.out
@@ -1,6 +1,6 @@
 --- remove-unnamed-operation.json
 +++ patched
-@@ -426,16 +426,6 @@
+@@
          "summary": "Get typed properties"
        }
      },
@@ -22,15 +22,25 @@
 Result for patch:
 [
     Change {
-        message: "The operation <unnamed> was removed",
-        old_path: [
-            "#/paths/~1unnamed/get",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/paths/~1unnamed/get",
+                ],
+                new: [
+                    "#/paths",
+                ],
+                comparison: Structural,
+            },
         ],
-        new_path: [
-            "#/paths",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "The operation <unnamed> was removed",
+                class: BackwardIncompatible,
+                details: Removed,
+            },
         ],
-        comparison: Structural,
-        class: BackwardIncompatible,
-        details: Removed,
     },
 ]
diff --git a/tests/cases/simple/output/schema-kind-type-to-oneof.out b/tests/cases/simple/output/schema-kind-type-to-oneof.out
index f6591ab..154c588 100644
--- a/tests/cases/simple/output/schema-kind-type-to-oneof.out
+++ b/tests/cases/simple/output/schema-kind-type-to-oneof.out
@@ -1,6 +1,6 @@
 --- schema-kind-type-to-oneof.json
 +++ patched
-@@ -135,12 +135,14 @@
+@@
          "$ref": "#/components/schemas/SubType"
        },
        "SubType": {
@@ -24,19 +24,29 @@
 Result for patch:
 [
     Change {
-        message: "schema kind changed from regular type to oneOf",
-        old_path: [
-            "#/components/schemas/SubType",
-            "#/components/schemas/GreetingResponse/properties/via_allof/0/$ref",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/SubType",
+                    "#/components/schemas/GreetingResponse/properties/via_allof/0/$ref",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/SubType",
+                    "#/components/schemas/GreetingResponse/properties/via_allof/0/$ref",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/SubType",
-            "#/components/schemas/GreetingResponse/properties/via_allof/0/$ref",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema kind changed from regular type to oneOf",
+                class: Incompatible,
+                details: Datatype,
+            },
         ],
-        comparison: Output,
-        class: Incompatible,
-        details: Datatype,
     },
 ]
diff --git a/tests/cases/simple/output/string-format-change.out b/tests/cases/simple/output/string-format-change.out
index 1f8edf0..ed74d51 100644
--- a/tests/cases/simple/output/string-format-change.out
+++ b/tests/cases/simple/output/string-format-change.out
@@ -1,6 +1,6 @@
 --- string-format-change.json
 +++ patched
-@@ -50,6 +50,7 @@
+@@
          "properties": {
            "message": {
              "description": "The greeting message",
@@ -13,17 +13,27 @@
 Result for patch:
 [
     Change {
-        message: "string schema changed",
-        old_path: [
-            "#/components/schemas/GreetingResponse/properties/message",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/GreetingResponse/properties/message",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponse/properties/message",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponse/properties/message",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "string schema changed",
+                class: Unhandled,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Unhandled,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/type-indirection.out b/tests/cases/simple/output/type-indirection.out
index 910cf39..7aabfb2 100644
--- a/tests/cases/simple/output/type-indirection.out
+++ b/tests/cases/simple/output/type-indirection.out
@@ -1,6 +1,6 @@
 --- type-indirection.json
 +++ patched
-@@ -49,8 +49,7 @@
+@@
        "GreetingResponse": {
          "properties": {
            "message": {
@@ -10,7 +10,7 @@
            },
            "not_a_number": {
              "not": {
-@@ -90,6 +89,13 @@
+@@
          ],
          "type": "object"
        },
@@ -29,18 +29,28 @@
 Result for patch:
 [
     Change {
-        message: "schema metadata changed",
-        old_path: [
-            "#/components/schemas/GreetingResponse/properties/message",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/GreetingResponse/properties/message",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponseMessage",
+                    "#/components/schemas/GreetingResponse/properties/message/$ref",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponseMessage",
-            "#/components/schemas/GreetingResponse/properties/message/$ref",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema metadata changed",
+                class: Trivial,
+                details: Metadata,
+            },
         ],
-        comparison: Output,
-        class: Trivial,
-        details: Metadata,
     },
 ]
diff --git a/tests/cases/simple/output/type-rename.out b/tests/cases/simple/output/type-rename.out
index bac28a3..b767464 100644
--- a/tests/cases/simple/output/type-rename.out
+++ b/tests/cases/simple/output/type-rename.out
@@ -1,6 +1,6 @@
 --- type-rename.json
 +++ patched
-@@ -46,7 +46,7 @@
+@@
          ],
          "type": "object"
        },
@@ -9,7 +9,7 @@
          "properties": {
            "message": {
              "description": "The greeting message",
-@@ -264,7 +264,7 @@
+@@
              "content": {
                "application/json": {
                  "schema": {
diff --git a/tests/cases/simple/output/unhandled-add-prop.out b/tests/cases/simple/output/unhandled-add-prop.out
index 37193a0..c45ca6f 100644
--- a/tests/cases/simple/output/unhandled-add-prop.out
+++ b/tests/cases/simple/output/unhandled-add-prop.out
@@ -1,6 +1,6 @@
 --- unhandled-add-prop.json
 +++ patched
-@@ -57,6 +57,10 @@
+@@
                "type": "number"
              }
            },
@@ -11,7 +11,7 @@
            "via_allof": {
              "allOf": [
                {
-@@ -86,7 +90,8 @@
+@@
            }
          },
          "required": [
@@ -26,31 +26,51 @@
 Result for patch:
 [
     Change {
-        message: "object required properties changed",
-        old_path: [
-            "#/components/schemas/GreetingResponse",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/GreetingResponse",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponse",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponse",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "object required properties changed",
+                class: Unhandled,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Unhandled,
-        details: UnknownDifference,
     },
     Change {
-        message: "object properties changed",
-        old_path: [
-            "#/components/schemas/GreetingResponse",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/GreetingResponse",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/GreetingResponse",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/GreetingResponse",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "object properties changed",
+                class: Unhandled,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Unhandled,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/cases/simple/output/wrapper-unchanged-with-type-change.out b/tests/cases/simple/output/wrapper-unchanged-with-type-change.out
index 7b96447..908f776 100644
--- a/tests/cases/simple/output/wrapper-unchanged-with-type-change.out
+++ b/tests/cases/simple/output/wrapper-unchanged-with-type-change.out
@@ -1,6 +1,6 @@
 --- wrapper-unchanged-with-type-change.json
 +++ patched
-@@ -137,7 +137,7 @@
+@@
        "SubType": {
          "properties": {
            "value": {
@@ -14,19 +14,29 @@
 Result for patch:
 [
     Change {
-        message: "schema types changed",
-        old_path: [
-            "#/components/schemas/SubType/properties/value",
-            "#/components/schemas/GreetingResponse/properties/via_allof/0/$ref",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        paths: [
+            ChangePath {
+                old: [
+                    "#/components/schemas/SubType/properties/value",
+                    "#/components/schemas/GreetingResponse/properties/via_allof/0/$ref",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                new: [
+                    "#/components/schemas/SubType/properties/value",
+                    "#/components/schemas/GreetingResponse/properties/via_allof/0/$ref",
+                    "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+                ],
+                comparison: Output,
+            },
         ],
-        new_path: [
-            "#/components/schemas/SubType/properties/value",
-            "#/components/schemas/GreetingResponse/properties/via_allof/0/$ref",
-            "#/paths/~1hello~1{name}/get/responses/200/content/application~1json/schema/$ref",
+        changes: [
+            ChangeInfo {
+                old_subpath: "",
+                new_subpath: "",
+                message: "schema types changed",
+                class: Incompatible,
+                details: UnknownDifference,
+            },
         ],
-        comparison: Output,
-        class: Incompatible,
-        details: UnknownDifference,
     },
 ]
diff --git a/tests/test_changes.rs b/tests/test_changes.rs
index 05ad940..c222a9f 100644
--- a/tests/test_changes.rs
+++ b/tests/test_changes.rs
@@ -1,4 +1,6 @@
-// Copyright 2025 Oxide Computer Company
+// Copyright 2026 Oxide Computer Company
+
+use std::fmt::Write;
 
 use drift::compare;
 use similar::TextDiff;
@@ -39,19 +41,31 @@ fn test_change() {
                     json_patch::patch(&mut patched, &patch_value).unwrap();
 
                     let udiff = {
-                        // Suppress the observation regarding the lack of a
-                        // terminating newline.
                         let mut base_pretty = serde_json::to_string_pretty(&base_value).unwrap();
                         base_pretty.push('\n');
                         let mut patched_pretty = serde_json::to_string_pretty(&patched).unwrap();
                         patched_pretty.push('\n');
                         let diff = TextDiff::from_lines(&base_pretty, &patched_pretty);
-                        diff.unified_diff()
-                            .header(
-                                patch_entry.file_name().to_string_lossy().as_ref(),
-                                "patched",
-                            )
-                            .to_string()
+                        let patch_name = patch_entry.file_name();
+
+                        // Format the unified diff manually, replacing `@@ -N,M
+                        // +N,M @@` hunk headers with bare `@@` to avoid churn
+                        // when base.json changes shift line positions.
+                        let mut out = String::new();
+                        let mut first = true;
+                        for hunk in diff.unified_diff().iter_hunks() {
+                            if first {
+                                writeln!(out, "--- {}", patch_name.to_string_lossy()).unwrap();
+                                writeln!(out, "+++ patched").unwrap();
+                                first = false;
+                            }
+                            writeln!(out, "@@").unwrap();
+                            for change in hunk.iter_changes() {
+                                write!(out, "{}{}", change.tag(), change.to_string_lossy())
+                                    .unwrap();
+                            }
+                        }
+                        out
                     };
 
                     let result =