diff --git a/.gitignore b/.gitignore
index 2949f09b..57538075 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,3 +6,6 @@ doc
 benchmark/implementations/*
 !/benchmark/implementations/current/
 dist/
+.claude/
+.codex/
+.agents/
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3e59030d..abf30a46 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -27,7 +27,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [4.0.0] - 2021-01-03
 ### Changed
-- Check [migration guide](migrate_v3_to_v4.md) to see details for all breaking changes.
+- Check migration guide in [docs](docs/) for details of all breaking changes.
 - Breaking: "unsafe" tags `!!js/function`, `!!js/regexp`, `!!js/undefined` are
   moved to [js-yaml-js-types](https://github.com/nodeca/js-yaml-js-types) package.
 - Breaking: removed `safe*` functions. Use `load`, `loadAll`, `dump`
diff --git a/bin/js-yaml.js b/bin/js-yaml.js
index 583e2999..abcd7e00 100755
--- a/bin/js-yaml.js
+++ b/bin/js-yaml.js
@@ -9,8 +9,8 @@ const yaml = require('..')
 /// /////////////////////////////////////////////////////////////////////////////
 
 const cli = new argparse.ArgumentParser({
-  prog:     'js-yaml',
-  add_help:  true
+  prog: 'js-yaml',
+  add_help: true
 })
 
 cli.add_argument('-v', '--version', {
@@ -19,26 +19,26 @@ cli.add_argument('-v', '--version', {
 })
 
 cli.add_argument('-c', '--compact', {
-  help:   'Display errors in compact mode',
+  help: 'Display errors in compact mode',
   action: 'store_true'
 })
 
 // deprecated (not needed after we removed output colors)
 // option suppressed, but not completely removed for compatibility
 cli.add_argument('-j', '--to-json', {
-  help:   argparse.SUPPRESS,
-  dest:   'json',
+  help: argparse.SUPPRESS,
+  dest: 'json',
   action: 'store_true'
 })
 
 cli.add_argument('-t', '--trace', {
-  help:   'Show stack trace on error',
+  help: 'Show stack trace on error',
   action: 'store_true'
 })
 
 cli.add_argument('file', {
-  help:   'File to read, utf-8 encoded without BOM',
-  nargs:  '?',
+  help: 'File to read, utf-8 encoded without BOM',
+  nargs: '?',
   default: '-'
 })
 
diff --git a/migrate_v3_to_v4.md b/docs/migrate_v3_to_v4.md
similarity index 100%
rename from migrate_v3_to_v4.md
rename to docs/migrate_v3_to_v4.md
diff --git a/docs/safety.md b/docs/safety.md
new file mode 100644
index 00000000..d7771218
--- /dev/null
+++ b/docs/safety.md
@@ -0,0 +1,57 @@
+# Safety notes for untrusted input
+
+The YAML spec by design allows compact documents that produce objects which are
+expensive to materialize. Guard against this when the input is untrusted.
+
+### 1. Limit input size
+
+Limit the input size to the smallest acceptable value.
+
+### 2. Catch all exceptions
+
+`load()` throws on malformed input. Always wrap it in `try/catch` and treat any
+error as a rejected document.
+
+### 3. Traverse with a node limit before materializing
+
+Aliases let a tiny document expand into a huge object graph (the "billion
+laughs" pattern) and can even create circular references. It stays cheap until
+you fully walk it (`JSON.stringify`, deep clone, recursive validation), so do a
+cheap pass first that counts every element and bails out past a limit.
+
+The walk is a flat loop over a manual stack — no recursion, so deep documents
+can't overflow the call stack. Counting happens as each element is discovered,
+so the stack never grows past the limit:
+
+```js
+// plain `{}` or `Object.create(null)`, but not Date / Uint8Array / etc.
+function isContainer(o) {
+  if (Array.isArray(o)) return true
+  if (!o || typeof o !== 'object') return false
+  const proto = Object.getPrototypeOf(o)
+  return proto === Object.prototype || proto === null
+}
+
+function guardNodeCount(root, limit) {
+  let count = 0
+  const stack = [ root ]
+
+  while (stack.length) {
+    const node = stack.pop()
+
+    for (const key in node) {
+      if (++count > limit) throw new Error('Too many nodes')
+      const value = node[key]
+      if (isContainer(value)) stack.push(value)
+    }
+  }
+}
+
+const data = yaml.load(input)
+guardNodeCount(data, 100000)
+const json = JSON.stringify(data)
+```
+
+Note: aliases that point to the same node are counted every time they appear
+(matching the real materialization cost), and a cyclic document keeps producing
+elements until it hits the limit — both are rejected as intended.
diff --git a/eslint.config.mjs b/eslint.config.mjs
index 0af9359d..cb5f9824 100644
--- a/eslint.config.mjs
+++ b/eslint.config.mjs
@@ -12,9 +12,6 @@ export default [
 
   {
     rules: {
-      camelcase: 'off',
-      '@stylistic/key-spacing': 'off',
-      'no-useless-escape': 'off',
       'object-shorthand': 'off',
     }
   }
diff --git a/examples/dumper.js b/examples/dumper.js
index d3fa3af6..337d99c9 100644
--- a/examples/dumper.js
+++ b/examples/dumper.js
@@ -6,8 +6,8 @@ const object = require('./dumper.json')
 console.log(yaml.dump(object, {
   flowLevel: 3,
   styles: {
-    '!!int'  : 'hexadecimal',
-    '!!null' : 'camelcase'
+    '!!int': 'hexadecimal',
+    '!!null': 'camelcase'
   }
 }))
 
diff --git a/index.js b/index.js
index 3d5d4142..0b66b8f2 100644
--- a/index.js
+++ b/index.js
@@ -23,19 +23,19 @@ module.exports.YAMLException = require('./lib/exception')
 
 // Re-export all types in case user wants to create custom schema
 module.exports.types = {
-  binary:    require('./lib/type/binary'),
-  float:     require('./lib/type/float'),
-  map:       require('./lib/type/map'),
-  null:      require('./lib/type/null'),
-  pairs:     require('./lib/type/pairs'),
-  set:       require('./lib/type/set'),
+  binary: require('./lib/type/binary'),
+  float: require('./lib/type/float'),
+  map: require('./lib/type/map'),
+  null: require('./lib/type/null'),
+  pairs: require('./lib/type/pairs'),
+  set: require('./lib/type/set'),
   timestamp: require('./lib/type/timestamp'),
-  bool:      require('./lib/type/bool'),
-  int:       require('./lib/type/int'),
-  merge:     require('./lib/type/merge'),
-  omap:      require('./lib/type/omap'),
-  seq:       require('./lib/type/seq'),
-  str:       require('./lib/type/str')
+  bool: require('./lib/type/bool'),
+  int: require('./lib/type/int'),
+  merge: require('./lib/type/merge'),
+  omap: require('./lib/type/omap'),
+  seq: require('./lib/type/seq'),
+  str: require('./lib/type/str')
 }
 
 // Removed functions from JS-YAML 3.0.x
diff --git a/lib/loader.js b/lib/loader.js
index 8256c2d4..fb1bd53b 100644
--- a/lib/loader.js
+++ b/lib/loader.js
@@ -19,28 +19,31 @@ const CHOMPING_KEEP = 3
 // eslint-disable-next-line no-control-regex
 const PATTERN_NON_PRINTABLE = /[\x00-\x08\x0B\x0C\x0E-\x1F\x7F-\x84\x86-\x9F\uFFFE\uFFFF]|[\uD800-\uDBFF](?![\uDC00-\uDFFF])|(?:[^\uD800-\uDBFF]|^)[\uDC00-\uDFFF]/
 const PATTERN_NON_ASCII_LINE_BREAKS = /[\x85\u2028\u2029]/
-const PATTERN_FLOW_INDICATORS = /[,\[\]\{\}]/
+// eslint-disable-next-line no-useless-escape
+const PATTERN_FLOW_INDICATORS = /[,\[\]{}]/
+// eslint-disable-next-line no-useless-escape
 const PATTERN_TAG_HANDLE = /^(?:!|!!|![a-z\-]+!)$/i
-const PATTERN_TAG_URI = /^(?:!|[^,\[\]\{\}])(?:%[0-9a-f]{2}|[0-9a-z\-#;\/\?:@&=\+\$,_\.!~\*'\(\)\[\]])*$/i
+// eslint-disable-next-line no-useless-escape
+const PATTERN_TAG_URI = /^(?:!|[^,\[\]{}])(?:%[0-9a-f]{2}|[0-9a-z\-#;/?:@&=+$,_.!~*'()\[\]])*$/i
 
 function _class (obj) { return Object.prototype.toString.call(obj) }
 
-function is_EOL (c) {
+function isEol (c) {
   return (c === 0x0A/* LF */) || (c === 0x0D/* CR */)
 }
 
-function is_WHITE_SPACE (c) {
+function isWhiteSpace (c) {
   return (c === 0x09/* Tab */) || (c === 0x20/* Space */)
 }
 
-function is_WS_OR_EOL (c) {
+function isWsOrEol (c) {
   return (c === 0x09/* Tab */) ||
          (c === 0x20/* Space */) ||
          (c === 0x0A/* LF */) ||
          (c === 0x0D/* CR */)
 }
 
-function is_FLOW_INDICATOR (c) {
+function isFlowIndicator (c) {
   return c === 0x2C/* , */ ||
          c === 0x5B/* [ */ ||
          c === 0x5D/* ] */ ||
@@ -177,11 +180,11 @@ function State (input, options) {
 
 function generateError (state, message) {
   const mark = {
-    name:     state.filename,
-    buffer:   state.input.slice(0, -1), // omit trailing \0
+    name: state.filename,
+    buffer: state.input.slice(0, -1), // omit trailing \0
     position: state.position,
-    line:     state.line,
-    column:   state.position - state.lineStart
+    line: state.line,
+    column: state.position - state.lineStart
   }
 
   mark.snippet = makeSnippet(mark)
@@ -381,7 +384,7 @@ function skipSeparationSpace (state, allowComments, checkIndent) {
   let ch = state.input.charCodeAt(state.position)
 
   while (ch !== 0) {
-    while (is_WHITE_SPACE(ch)) {
+    while (isWhiteSpace(ch)) {
       if (ch === 0x09/* Tab */ && state.firstTabInLine === -1) {
         state.firstTabInLine = state.position
       }
@@ -394,7 +397,7 @@ function skipSeparationSpace (state, allowComments, checkIndent) {
       } while (ch !== 0x0A/* LF */ && ch !== 0x0D/* CR */ && ch !== 0)
     }
 
-    if (is_EOL(ch)) {
+    if (isEol(ch)) {
       readLineBreak(state)
 
       ch = state.input.charCodeAt(state.position)
@@ -430,7 +433,7 @@ function testDocumentSeparator (state) {
 
     ch = state.input.charCodeAt(_position)
 
-    if (ch === 0 || is_WS_OR_EOL(ch)) {
+    if (ch === 0 || isWsOrEol(ch)) {
       return true
     }
   }
@@ -458,8 +461,8 @@ function readPlainScalar (state, nodeIndent, withinFlowCollection) {
 
   let ch = state.input.charCodeAt(state.position)
 
-  if (is_WS_OR_EOL(ch) ||
-      is_FLOW_INDICATOR(ch) ||
+  if (isWsOrEol(ch) ||
+      isFlowIndicator(ch) ||
       ch === 0x23/* # */ ||
       ch === 0x26/* & */ ||
       ch === 0x2A/* * */ ||
@@ -477,8 +480,8 @@ function readPlainScalar (state, nodeIndent, withinFlowCollection) {
   if (ch === 0x3F/* ? */ || ch === 0x2D/* - */) {
     const following = state.input.charCodeAt(state.position + 1)
 
-    if (is_WS_OR_EOL(following) ||
-        (withinFlowCollection && is_FLOW_INDICATOR(following))) {
+    if (isWsOrEol(following) ||
+        (withinFlowCollection && isFlowIndicator(following))) {
       return false
     }
   }
@@ -492,20 +495,20 @@ function readPlainScalar (state, nodeIndent, withinFlowCollection) {
     if (ch === 0x3A/* : */) {
       const following = state.input.charCodeAt(state.position + 1)
 
-      if (is_WS_OR_EOL(following) ||
-          (withinFlowCollection && is_FLOW_INDICATOR(following))) {
+      if (isWsOrEol(following) ||
+          (withinFlowCollection && isFlowIndicator(following))) {
         break
       }
     } else if (ch === 0x23/* # */) {
       const preceding = state.input.charCodeAt(state.position - 1)
 
-      if (is_WS_OR_EOL(preceding)) {
+      if (isWsOrEol(preceding)) {
         break
       }
     } else if ((state.position === state.lineStart && testDocumentSeparator(state)) ||
-               (withinFlowCollection && is_FLOW_INDICATOR(ch))) {
+               (withinFlowCollection && isFlowIndicator(ch))) {
       break
-    } else if (is_EOL(ch)) {
+    } else if (isEol(ch)) {
       _line = state.line
       _lineStart = state.lineStart
       _lineIndent = state.lineIndent
@@ -531,7 +534,7 @@ function readPlainScalar (state, nodeIndent, withinFlowCollection) {
       hasPendingContent = false
     }
 
-    if (!is_WHITE_SPACE(ch)) {
+    if (!isWhiteSpace(ch)) {
       captureEnd = state.position + 1
     }
 
@@ -576,7 +579,7 @@ function readSingleQuotedScalar (state, nodeIndent) {
       } else {
         return true
       }
-    } else if (is_EOL(ch)) {
+    } else if (isEol(ch)) {
       captureSegment(state, captureStart, captureEnd, true)
       writeFoldedLines(state, skipSeparationSpace(state, false, nodeIndent))
       captureStart = captureEnd = state.position
@@ -616,7 +619,7 @@ function readDoubleQuotedScalar (state, nodeIndent) {
       captureSegment(state, captureStart, state.position, true)
       ch = state.input.charCodeAt(++state.position)
 
-      if (is_EOL(ch)) {
+      if (isEol(ch)) {
         skipSeparationSpace(state, false, nodeIndent)
 
         // TODO: rework to inline fn with no type cast?
@@ -645,7 +648,7 @@ function readDoubleQuotedScalar (state, nodeIndent) {
       }
 
       captureStart = captureEnd = state.position
-    } else if (is_EOL(ch)) {
+    } else if (isEol(ch)) {
       captureSegment(state, captureStart, captureEnd, true)
       writeFoldedLines(state, skipSeparationSpace(state, false, nodeIndent))
       captureStart = captureEnd = state.position
@@ -722,7 +725,7 @@ function readFlowCollection (state, nodeIndent) {
     if (ch === 0x3F/* ? */) {
       const following = state.input.charCodeAt(state.position + 1)
 
-      if (is_WS_OR_EOL(following)) {
+      if (isWsOrEol(following)) {
         isPair = isExplicitPair = true
         state.position++
         skipSeparationSpace(state, true, nodeIndent)
@@ -816,13 +819,13 @@ function readBlockScalar (state, nodeIndent) {
     }
   }
 
-  if (is_WHITE_SPACE(ch)) {
+  if (isWhiteSpace(ch)) {
     do { ch = state.input.charCodeAt(++state.position) }
-    while (is_WHITE_SPACE(ch))
+    while (isWhiteSpace(ch))
 
     if (ch === 0x23/* # */) {
       do { ch = state.input.charCodeAt(++state.position) }
-      while (!is_EOL(ch) && (ch !== 0))
+      while (!isEol(ch) && (ch !== 0))
     }
   }
 
@@ -843,7 +846,7 @@ function readBlockScalar (state, nodeIndent) {
       textIndent = state.lineIndent
     }
 
-    if (is_EOL(ch)) {
+    if (isEol(ch)) {
       emptyLines++
       continue
     }
@@ -866,7 +869,7 @@ function readBlockScalar (state, nodeIndent) {
     // Folded style: use fancy rules to handle line breaks.
     if (folding) {
       // Lines starting with white space characters (more-indented lines) are not folded.
-      if (is_WHITE_SPACE(ch)) {
+      if (isWhiteSpace(ch)) {
         atMoreIndented = true
         // except for the first content line (cf. Example 8.1)
         state.result += common.repeat('\n', didReadContent ? 1 + emptyLines : emptyLines)
@@ -898,7 +901,7 @@ function readBlockScalar (state, nodeIndent) {
     emptyLines = 0
     const captureStart = state.position
 
-    while (!is_EOL(ch) && (ch !== 0)) {
+    while (!isEol(ch) && (ch !== 0)) {
       ch = state.input.charCodeAt(++state.position)
     }
 
@@ -936,7 +939,7 @@ function readBlockSequence (state, nodeIndent) {
 
     const following = state.input.charCodeAt(state.position + 1)
 
-    if (!is_WS_OR_EOL(following)) {
+    if (!isWsOrEol(following)) {
       break
     }
 
@@ -1013,7 +1016,7 @@ function readBlockMapping (state, nodeIndent, flowIndent) {
     // Explicit notation case. There are two separate blocks:
     // first for the key (denoted by "?") and second for the value (denoted by ":")
     //
-    if ((ch === 0x3F/* ? */ || ch === 0x3A/* : */) && is_WS_OR_EOL(following)) {
+    if ((ch === 0x3F/* ? */ || ch === 0x3A/* : */) && isWsOrEol(following)) {
       if (ch === 0x3F/* ? */) {
         if (atExplicitKey) {
           storeMappingPair(state, _result, overridableKeys, keyTag, keyNode, null, _keyLine, _keyLineStart, _keyPos)
@@ -1051,14 +1054,14 @@ function readBlockMapping (state, nodeIndent, flowIndent) {
       if (state.line === _line) {
         ch = state.input.charCodeAt(state.position)
 
-        while (is_WHITE_SPACE(ch)) {
+        while (isWhiteSpace(ch)) {
           ch = state.input.charCodeAt(++state.position)
         }
 
         if (ch === 0x3A/* : */) {
           ch = state.input.charCodeAt(++state.position)
 
-          if (!is_WS_OR_EOL(ch)) {
+          if (!isWsOrEol(ch)) {
             throwError(state, 'a whitespace character is expected after the key-value separator within a block mapping')
           }
 
@@ -1182,7 +1185,7 @@ function readTagProperty (state) {
       throwError(state, 'unexpected end of the stream within a verbatim tag')
     }
   } else {
-    while (ch !== 0 && !is_WS_OR_EOL(ch)) {
+    while (ch !== 0 && !isWsOrEol(ch)) {
       if (ch === 0x21/* ! */) {
         if (!isNamed) {
           tagHandle = state.input.slice(_position - 1, state.position + 1)
@@ -1245,7 +1248,7 @@ function readAnchorProperty (state) {
   ch = state.input.charCodeAt(++state.position)
   const _position = state.position
 
-  while (ch !== 0 && !is_WS_OR_EOL(ch) && !is_FLOW_INDICATOR(ch)) {
+  while (ch !== 0 && !isWsOrEol(ch) && !isFlowIndicator(ch)) {
     ch = state.input.charCodeAt(++state.position)
   }
 
@@ -1265,7 +1268,7 @@ function readAlias (state) {
   ch = state.input.charCodeAt(++state.position)
   const _position = state.position
 
-  while (ch !== 0 && !is_WS_OR_EOL(ch) && !is_FLOW_INDICATOR(ch)) {
+  while (ch !== 0 && !isWsOrEol(ch) && !isFlowIndicator(ch)) {
     ch = state.input.charCodeAt(++state.position)
   }
 
@@ -1478,7 +1481,7 @@ function readDocument (state) {
     ch = state.input.charCodeAt(++state.position)
     let _position = state.position
 
-    while (ch !== 0 && !is_WS_OR_EOL(ch)) {
+    while (ch !== 0 && !isWsOrEol(ch)) {
       ch = state.input.charCodeAt(++state.position)
     }
 
@@ -1490,21 +1493,21 @@ function readDocument (state) {
     }
 
     while (ch !== 0) {
-      while (is_WHITE_SPACE(ch)) {
+      while (isWhiteSpace(ch)) {
         ch = state.input.charCodeAt(++state.position)
       }
 
       if (ch === 0x23/* # */) {
         do { ch = state.input.charCodeAt(++state.position) }
-        while (ch !== 0 && !is_EOL(ch))
+        while (ch !== 0 && !isEol(ch))
         break
       }
 
-      if (is_EOL(ch)) break
+      if (isEol(ch)) break
 
       _position = state.position
 
-      while (ch !== 0 && !is_WS_OR_EOL(ch)) {
+      while (ch !== 0 && !isWsOrEol(ch)) {
         ch = state.input.charCodeAt(++state.position)
       }
 
diff --git a/lib/type/int.js b/lib/type/int.js
index c4670b0f..b21bfea7 100644
--- a/lib/type/int.js
+++ b/lib/type/int.js
@@ -138,16 +138,16 @@ module.exports = new Type('tag:yaml.org,2002:int', {
   construct: constructYamlInteger,
   predicate: isInteger,
   represent: {
-    binary:      function (obj) { return obj >= 0 ? '0b' + obj.toString(2) : '-0b' + obj.toString(2).slice(1) },
-    octal:       function (obj) { return obj >= 0 ? '0o' + obj.toString(8) : '-0o' + obj.toString(8).slice(1) },
-    decimal:     function (obj) { return obj.toString(10) },
+    binary: function (obj) { return obj >= 0 ? '0b' + obj.toString(2) : '-0b' + obj.toString(2).slice(1) },
+    octal: function (obj) { return obj >= 0 ? '0o' + obj.toString(8) : '-0o' + obj.toString(8).slice(1) },
+    decimal: function (obj) { return obj.toString(10) },
     hexadecimal: function (obj) { return obj >= 0 ? '0x' + obj.toString(16).toUpperCase() : '-0x' + obj.toString(16).toUpperCase().slice(1) }
   },
   defaultStyle: 'decimal',
   styleAliases: {
-    binary:      [2, 'bin'],
-    octal:       [8, 'oct'],
-    decimal:     [10, 'dec'],
+    binary: [2, 'bin'],
+    octal: [8, 'oct'],
+    decimal: [10, 'dec'],
     hexadecimal: [16, 'hex']
   }
 })
diff --git a/lib/type/null.js b/lib/type/null.js
index cbae3bdc..0a9d7e56 100644
--- a/lib/type/null.js
+++ b/lib/type/null.js
@@ -29,7 +29,7 @@ module.exports = new Type('tag:yaml.org,2002:null', {
     lowercase: function () { return 'null' },
     uppercase: function () { return 'NULL' },
     camelcase: function () { return 'Null' },
-    empty:     function () { return '' }
+    empty: function () { return '' }
   },
   defaultStyle: 'lowercase'
 })
diff --git a/lib/type/timestamp.js b/lib/type/timestamp.js
index 771474ea..05f323b6 100644
--- a/lib/type/timestamp.js
+++ b/lib/type/timestamp.js
@@ -16,8 +16,8 @@ const YAML_TIMESTAMP_REGEXP = new RegExp(
   ':([0-9][0-9])' + // [5] minute
   ':([0-9][0-9])' + // [6] second
   '(?:\\.([0-9]*))?' + // [7] fraction
-  '(?:[ \\t]*(Z|([-+])([0-9][0-9]?)' + // [8] tz [9] tz_sign [10] tz_hour
-  '(?::([0-9][0-9]))?))?$')           // [11] tz_minute
+  '(?:[ \\t]*(Z|([-+])([0-9][0-9]?)' + // [8] tz [9] tz_sign [10] tzHour
+  '(?::([0-9][0-9]))?))?$')           // [11] tzMinute
 
 function resolveYamlTimestamp (data) {
   if (data === null) return false
@@ -59,12 +59,12 @@ function constructYamlTimestamp (data) {
     fraction = +fraction
   }
 
-  // match: [8] tz [9] tz_sign [10] tz_hour [11] tz_minute
+  // match: [8] tz [9] tz_sign [10] tzHour [11] tzMinute
 
   if (match[9]) {
-    const tz_hour = +(match[10])
-    const tz_minute = +(match[11] || 0)
-    delta = (tz_hour * 60 + tz_minute) * 60000 // delta in mili-seconds
+    const tzHour = +(match[10])
+    const tzMinute = +(match[11] || 0)
+    delta = (tzHour * 60 + tzMinute) * 60000 // delta in mili-seconds
     if (match[9] === '-') delta = -delta
   }
 
diff --git a/package.json b/package.json
index 5b289fb5..914e3f35 100644
--- a/package.json
+++ b/package.json
@@ -35,6 +35,7 @@
   },
   "scripts": {
     "lint": "eslint .",
+    "lint-fix": "eslint . --fix",
     "test": "npm run lint && npm run test:core && npm run test:build",
     "test:core": "node --test test/core/*.test.*",
     "test:build": "npm run build && node --test test/build/*.test.*",
diff --git a/support/demo_template/index.mjs b/support/demo_template/index.mjs
index 7ccb5a90..857d557c 100644
--- a/support/demo_template/index.mjs
+++ b/support/demo_template/index.mjs
@@ -1,7 +1,7 @@
 import jsyaml from '../../lib/index_vite_proxy.tmp.mjs'
 import codemirror from 'codemirror'
 import { inspect } from 'util'
-import default_text from './sample.mjs'
+import defaultText from './sample.mjs'
 
 import 'codemirror/lib/codemirror.css'
 import 'codemirror/mode/yaml/yaml.js'
@@ -56,7 +56,7 @@ function updateSource () {
     yaml = decodeBase64(location.hash.slice(6))
   }
 
-  source.setValue(yaml || default_text)
+  source.setValue(yaml || defaultText)
   parse()
 }
 
diff --git a/test/core/issues/0303.js b/test/core/issues/0303.js
index ef0ffaab..9bc41272 100644
--- a/test/core/issues/0303.js
+++ b/test/core/issues/0303.js
@@ -6,8 +6,8 @@ const assert = require('assert')
 const yaml = require('js-yaml')
 
 it('Loader should not strip quotes before newlines', function () {
-  const with_space = yaml.load("'''foo'' '")
-  const with_newline = yaml.load("'''foo''\n'")
-  assert.strictEqual(with_space, "'foo' ")
-  assert.strictEqual(with_newline, "'foo' ")
+  const withSpace = yaml.load("'''foo'' '")
+  const withNewline = yaml.load("'''foo''\n'")
+  assert.strictEqual(withSpace, "'foo' ")
+  assert.strictEqual(withNewline, "'foo' ")
 })
diff --git a/test/core/issues/0529.js b/test/core/issues/0529.js
index bc913fd4..6060fbae 100644
--- a/test/core/issues/0529.js
+++ b/test/core/issues/0529.js
@@ -94,7 +94,7 @@ empty: ''
     assert.strictEqual(yaml.dump(sample, { quotingType: "'", forceQuotes: false }), expected)
   })
 
-  it('quotingType=\", forceQuotes=false', function () {
+  it('quotingType=", forceQuotes=false', function () {
     const expected = `
 simple_key: value
 foo'bar"baz: 1
@@ -159,7 +159,7 @@ empty: ''
     assert.strictEqual(yaml.dump(sample, { quotingType: "'", forceQuotes: true }), expected)
   })
 
-  it('quotingType=\", forceQuotes=true', function () {
+  it('quotingType=", forceQuotes=true', function () {
     const expected = `
 simple_key: "value"
 foo'bar"baz: 1
diff --git a/test/core/issues/0571.js b/test/core/issues/0571.js
index bbd06e58..a2513d1a 100644
--- a/test/core/issues/0571.js
+++ b/test/core/issues/0571.js
@@ -14,7 +14,7 @@ describe('Undefined', function () {
     represent: () => ''
   })
 
-  const undef_schema = yaml.DEFAULT_SCHEMA.extend(undef)
+  const undefSchema = yaml.DEFAULT_SCHEMA.extend(undef)
 
   it('Should replace undefined with null in collections', function () {
     let str
@@ -59,16 +59,16 @@ describe('Undefined', function () {
   it('Should serialize undefined if schema is available', function () {
     assert.deepStrictEqual(
       yaml.load(
-        yaml.dump([1, undefined, null, 2], { schema: undef_schema }),
-        { schema: undef_schema }
+        yaml.dump([1, undefined, null, 2], { schema: undefSchema }),
+        { schema: undefSchema }
       ),
       [1, undefined, null, 2]
     )
 
     assert.deepStrictEqual(
       yaml.load(
-        yaml.dump({ foo: 1, bar: undefined, baz: null }, { schema: undef_schema }),
-        { schema: undef_schema }
+        yaml.dump({ foo: 1, bar: undefined, baz: null }, { schema: undefSchema }),
+        { schema: undefSchema }
       ),
       { foo: 1, bar: undefined, baz: null }
     )
diff --git a/test/core/issues/0576.js b/test/core/issues/0576.js
index 3137f4fb..f8a2dbf2 100644
--- a/test/core/issues/0576.js
+++ b/test/core/issues/0576.js
@@ -6,11 +6,11 @@ const assert = require('assert')
 const yaml = require('js-yaml')
 
 describe('Custom tags', function () {
-  const tag_names = ['tag', '!tag', '!!tag', '!<!tag>', 'tag*-!< >{\n}', '!tagαβγ']
+  const tagNames = ['tag', '!tag', '!!tag', '!<!tag>', 'tag*-!< >{\n}', '!tagαβγ']
   const encoded = ['!<tag>', '!tag', '!%21tag', '!%3C%21tag%3E',
     '!<tag*-%21%3C%20%3E%7B%0A%7D>', '!tag%CE%B1%CE%B2%CE%B3']
 
-  const tags = tag_names.map(tag =>
+  const tags = tagNames.map(tag =>
     new yaml.Type(tag, {
       kind: 'scalar',
       resolve: () => true,
@@ -23,14 +23,14 @@ describe('Custom tags', function () {
   const schema = yaml.DEFAULT_SCHEMA.extend(tags)
 
   it('Should dump tags with proper encoding', function () {
-    tag_names.forEach(function (tag, idx) {
+    tagNames.forEach(function (tag, idx) {
       assert.strictEqual(yaml.dump({ tag }, { schema }), encoded[idx] + ' value\n')
     })
   })
 
   it('Should decode tags when loading', function () {
     encoded.forEach(function (tag, idx) {
-      assert.deepStrictEqual(yaml.load(tag + ' value', { schema }), [tag_names[idx], 'value'])
+      assert.deepStrictEqual(yaml.load(tag + ' value', { schema }), [tagNames[idx], 'value'])
     })
   })
 
diff --git a/test/core/issues/0586.js b/test/core/issues/0586.js
index 12fb3ca4..f5dc4a25 100644
--- a/test/core/issues/0586.js
+++ b/test/core/issues/0586.js
@@ -35,7 +35,7 @@ it('Should allow custom formatting through implicit custom tags', function () {
     return value // default
   }
 
-  const result = CustomDump({ flow_choices : [1, 2], block_choices: [4, 5] }).represent().trim()
+  const result = CustomDump({ flow_choices: [1, 2], block_choices: [4, 5] }).represent().trim()
 
   assert.strictEqual(result, `
 flow_choices: [1, 2]
diff --git a/test/core/samples-common/construct-omap.js b/test/core/samples-common/construct-omap.js
index 8c41dcf5..bb06b5e6 100644
--- a/test/core/samples-common/construct-omap.js
+++ b/test/core/samples-common/construct-omap.js
@@ -2,13 +2,13 @@
 
 module.exports = {
   Bestiary: [
-    { aardvark : 'African pig-like ant eater. Ugly.' },
-    { anteater : 'South-American ant eater. Two species.' },
-    { anaconda : 'South-American constrictor snake. Scaly.' }
+    { aardvark: 'African pig-like ant eater. Ugly.' },
+    { anteater: 'South-American ant eater. Two species.' },
+    { anaconda: 'South-American constrictor snake. Scaly.' }
   ],
   Numbers: [
-    { one   : 1 },
-    { two   : 2 },
-    { three : 3 }
+    { one: 1 },
+    { two: 2 },
+    { three: 3 }
   ]
 }
diff --git a/test/core/samples-common/construct-timestamp.js b/test/core/samples-common/construct-timestamp.js
index d82b88c1..3b3f99b0 100644
--- a/test/core/samples-common/construct-timestamp.js
+++ b/test/core/samples-common/construct-timestamp.js
@@ -1,9 +1,9 @@
 'use strict'
 
 module.exports = {
-  canonical:        new Date(Date.UTC(2001, 11, 15, 2, 59, 43, 100)),
-  'valid iso8601':    new Date(Date.UTC(2001, 11, 15, 2, 59, 43, 100)),
-  'space separated':  new Date(Date.UTC(2001, 11, 15, 2, 59, 43, 100)),
+  canonical: new Date(Date.UTC(2001, 11, 15, 2, 59, 43, 100)),
+  'valid iso8601': new Date(Date.UTC(2001, 11, 15, 2, 59, 43, 100)),
+  'space separated': new Date(Date.UTC(2001, 11, 15, 2, 59, 43, 100)),
   'no time zone (Z)': new Date(Date.UTC(2001, 11, 15, 2, 59, 43, 100)),
   'date (00:00:00Z)': new Date(Date.UTC(2002, 11, 14)),
   'not a date': '2002-1-1'
diff --git a/test/core/samples-common/dump-empty-collections.js b/test/core/samples-common/dump-empty-collections.js
index 0591ac63..bea5772c 100644
--- a/test/core/samples-common/dump-empty-collections.js
+++ b/test/core/samples-common/dump-empty-collections.js
@@ -1,6 +1,6 @@
 'use strict'
 
 module.exports = {
-  emptyArray:  [],
+  emptyArray: [],
   emptyObject: {}
 }
diff --git a/test/core/support/schema.js b/test/core/support/schema.js
index f4bcf84f..11e0f701 100644
--- a/test/core/support/schema.js
+++ b/test/core/support/schema.js
@@ -86,14 +86,14 @@ const TEST_SCHEMA = yaml.DEFAULT_SCHEMA.extend([
     },
     construct: function (data) {
       return new Foo({
-        myParameter:        data['my-parameter'],
+        myParameter: data['my-parameter'],
         myAnotherParameter: data['my-another-parameter']
       })
     },
     instanceOf: Foo,
     represent: function (object) {
       return {
-        'my-parameter':         object.myParameter,
+        'my-parameter': object.myParameter,
         'my-another-parameter': object.myAnotherParameter
       }
     }
diff --git a/test/core/units/replacer.js b/test/core/units/replacer.js
index 9298ace8..49737f00 100644
--- a/test/core/units/replacer.js
+++ b/test/core/units/replacer.js
@@ -14,7 +14,7 @@ describe('replacer', function () {
     represent: () => ''
   })
 
-  const undef_schema = yaml.DEFAULT_SCHEMA.extend(undef)
+  const undefSchema = yaml.DEFAULT_SCHEMA.extend(undef)
 
   it('should be called on the root of the document', function () {
     let called = 0
@@ -127,9 +127,9 @@ describe('replacer', function () {
         if (key === 'b') return undefined
         return value
       },
-      schema: undef_schema
+      schema: undefSchema
     })
-    result = yaml.load(str, { schema: undef_schema })
+    result = yaml.load(str, { schema: undefSchema })
     assert.deepStrictEqual(result, { a: 1, b: undefined, c: 3 })
   })
 
@@ -148,9 +148,9 @@ describe('replacer', function () {
         if (key === '1') return undefined
         return value
       },
-      schema: undef_schema
+      schema: undefSchema
     })
-    result = yaml.load(str, { schema: undef_schema })
+    result = yaml.load(str, { schema: undefSchema })
     assert.deepStrictEqual(result, [1, undefined, 3])
   })
 
diff --git a/test/core/units/skip-invalid.js b/test/core/units/skip-invalid.js
index 2bb05ac2..c9d0a3a9 100644
--- a/test/core/units/skip-invalid.js
+++ b/test/core/units/skip-invalid.js
@@ -8,15 +8,15 @@ const yaml = require('js-yaml')
 const sample = {
   number: 42,
   string: 'hello',
-  func:   function (a, b) { return a + b },
+  func: function (a, b) { return a + b },
   regexp: /^hel+o/,
-  array:  [1, 2, 3]
+  array: [1, 2, 3]
 }
 
 const expected = {
   number: 42,
   string: 'hello',
-  array:  [1, 2, 3]
+  array: [1, 2, 3]
 }
 
 it('Dumper must throw an exception on invalid type when option `skipInvalid` is false.', function () {