Add golden file tests

.bcr/presubmit.yml

@@ -8,5 +8,5 @@ bcr_test_module:
       name: "Build module"
       platform: ${{ platform }}
       bazel: ${{ bazel }}
-      build_targets:
+      test_targets:
         - "//..."

.github/workflows/ci.yaml

@@ -25,10 +25,10 @@ jobs:
           disk-cache: true
           # Share repository cache between workflows.
           repository-cache: true
-      - name: bazel build
+      - name: bazel test
         run: >-
           bazelisk
           --bazelrc=.github/workflows/ci.bazelrc
           --bazelrc=.bazelrc
-          build
-          ...
+          test
+          //...

.github/workflows/release_ruleset.yaml

@@ -93,7 +93,7 @@ jobs:
       # Fetch built artifacts (if any) from earlier jobs, which the release script may want to read.
       # Extract into ${GITHUB_WORKSPACE}/artifacts/*
       - uses: actions/download-artifact@95815c38cf2ff2164869cbab79da8d1f422bc89e # v4.2.1
-    
+
       - name: Build release artifacts and prepare release notes
         run: |
           if [ ! -f ".github/workflows/release_prep.sh" ]; then
@@ -205,4 +205,4 @@ jobs:
           tag_name: ${{ inputs.tag_name }}
           files: |
             release_files/**/*
-            attestations/*
+            attestations/*

MODULE.bazel

@@ -12,7 +12,7 @@ module(
 
 bazel_dep(name = "aspect_rules_js", version = "2.6.0")
 bazel_dep(name = "aspect_rules_ts", version = "3.7.0")
-bazel_dep(name = "bazel_skylib", version = "1.8.1")
+bazel_dep(name = "bazel_skylib", version = "1.8.2")
 bazel_dep(name = "rules_nodejs", version = "6.5.0")
 
 # --------------------------------------------------------------------------------

examples/helloworld/BUILD.bazel

@@ -1,13 +1,14 @@
 load("//rules:defs.bzl", "closure_ts_compile")
+load("//rules:testing.bzl", "golden_file_test")
 
 closure_ts_compile(
     name = "lib",
     srcs = ["index.ts"],
 )
 
-# bazel run //examples/helloworld:files.update
-# bazel test //examples/helloworld:files.test
-# golden_filegroup(
-#     name = "files",
-#     srcs = [":index.ts"],
-# )
+# bazel test //examples/helloworld:golden_test
+# bazel run //examples/helloworld:golden_test.update
+golden_file_test(
+    name = "golden_test",
+    srcs = [":lib"],
+)

examples/helloworld/index.js.golden

@@ -0,0 +1,15 @@
+/**
+ * @fileoverview added by tsickle
+ * Generated from: examples/helloworld/index.ts
+ */
+goog.module('examples.helloworld.index');
+var module = module || { id: 'examples/helloworld/index.ts' };
+goog.require('tslib');
+/**
+ * @param {string} name
+ * @return {string}
+ */
+function sayHello(name) {
+    return `hello, ${name}!`;
+}
+exports.sayHello = sayHello;

rules/testing.bzl

@@ -0,0 +1,102 @@
+def _golden_file_test_impl(ctx):
+    outputs = [ctx.outputs.executable]
+
+    content = "\n".join([
+        """
+if diff -u {dst} {src}; then
+    echo "files contents are identical"
+else
+    echo "files differ"
+    exit 1
+fi
+""".format(
+            src = src.short_path,
+            dst = src.short_path + ".golden",
+        )
+        for src in ctx.files.srcs
+    ])
+
+    ctx.actions.write(
+        ctx.outputs.executable,
+        "set -x\n\n" + content,
+        is_executable = True,
+    )
+    return [
+        DefaultInfo(
+            files = depset(outputs),
+            runfiles = ctx.runfiles(files = ctx.files.srcs + ctx.files.goldens),
+        ),
+    ]
+
+_golden_file_test = rule(
+    doc = "Asserts the two files are equal",
+    implementation = _golden_file_test_impl,
+    attrs = {
+        "srcs": attr.label_list(
+            doc = "the source files under test",
+            allow_files = True,
+            mandatory = True,
+        ),
+        "goldens": attr.label_list(
+            doc = "the expected golden files",
+            allow_files = True,
+            mandatory = True,
+        ),
+    },
+    executable = True,
+    test = True,
+)
+
+def _golden_file_update_impl(ctx):
+    outputs = [ctx.outputs.executable]
+
+    content = "\n".join([
+        """
+cp -f {src} {dst}
+echo "Updated golden file: {dst}"
+""".format(
+            src = src.short_path,
+            dst = "$BUILD_WORKING_DIRECTORY/%s/%s.golden" % (ctx.label.package, src.basename),
+        )
+        for src in ctx.files.srcs
+    ])
+
+    ctx.actions.write(
+        ctx.outputs.executable,
+        "set -x\n\n" + content,
+        is_executable = True,
+    )
+    return [
+        DefaultInfo(
+            files = depset(outputs),
+            runfiles = ctx.runfiles(files = ctx.files.srcs),
+        ),
+    ]
+
+_golden_file_update = rule(
+    doc = "Asserts the two files are equal",
+    implementation = _golden_file_update_impl,
+    attrs = {
+        "srcs": attr.label_list(
+            doc = "the source files to update",
+            allow_files = True,
+            mandatory = True,
+        ),
+    },
+    executable = True,
+)
+
+def golden_file_test(name, srcs, **kwargs):
+    tags = kwargs.get("tags", [])
+    _golden_file_test(
+        name = name,
+        srcs = srcs,
+        goldens = native.glob(["*.golden"]),
+        tags = tags,
+        **kwargs
+    )
+    _golden_file_update(
+        name = name + ".update",
+        srcs = srcs,
+        tags = tags,
+    )