21.1.0

@schematics/angular

Commit	Description
	add browserMode option to jasmine-vitest schematic
	generate detailed migration report for refactor-jasmine-vitest
	add MCP configuration file to new workspaces

@angular/cli

Commit	Description
	add 'test' and 'e2e' MCP tools
	Add "all" as an experimental tool group
	Add MCP tools for building and running devservers
	add signal forms lessons
	correctly handle yarn classic tag manifest fetching
	correctly spawn package managers on Windows in new abstraction
	enhance list_projects MCP tool file system traversal and symlink handling
	handle array output from npm view in manifest parser
	improve signal forms lesson examples in AI tutor
	rename mcp devserver tools to comply with naming spec
	update dependency @modelcontextprotocol/sdk to v1.25.2
	update yarn berry package manager configuration
	use project-local temporary directory in ng add
	cache resolved specific version in package manager abstraction
	optimize ng add version discovery

@angular/build

Commit	Description
	directly support ng-packagr in unit-test builder
	disable TestBed teardown during debugging in Vitest
	inject source-map-support for Vitest browser tests
	normalize roots to POSIX in test discovery for Windows compatibility
	resolve test files correctly on Windows when using non-C drives
	simplify SSL handling for ng serve with SSR (#31722)

21.0.6

@angular/ssr

Commit	Description
	handle platform destruction during rendering

21.0.5

@schematics/angular

Commit	Description
	move 'provideZoneChangeDetection' to the root module
	update application schematics for module-based apps to use 'provideZoneChangeDetection'
	update default app component message
	update default app component welcome message

@angular/cli

Commit	Description
	use narrower types for new MCP TS SDK compatibility

@angular/build

Commit	Description
	ensure correct project targeting during Vitest debugging

21.0.4

@schematics/angular

Commit	Description
	improve VS Code background compilation start/end detection
	remove inlineSources from library tsconfig template

@angular/build

Commit	Description
	add browser condition to resolver for vitest
	allow non-prefixed requests when using SSR and base href
	conditionally manage Vitest UI option
	ensure tests run when compilation error is resolved
	remove LmdbCacheStore export from private API

@angular/ssr

Commit	Description
	add leading slash to well-known non-Angular URLs
	propagate status code to redirect
	skip SSR processing for well-known non-Angular URLs like favicon.ico

21.0.3

@angular-devkit/build-angular

Commit	Description
	conditionally provide Zone.js change detection in the built-in test main file

@angular/build

Commit	Description
	Add custom middleware for to present an Angular-tailored message
	Ensure disposal of close-javascript-transformer
	ensure locale base href retains leading slash (#32040)
	inject testing polyfills in Karma unit-test executor
	support NODE_EXTRA_CA_CERTS in SSR SSL plugin

21.0.2

@angular/cli

Commit	Description
	update @modelcontextprotocol/sdk to v1.24.0

@angular-devkit/schematics

Commit	Description
	remove lazy imports in node tasks

@angular/build

Commit	Description
	add filename truncation to test discovery
	allow overriding Vitest coverage reportsDirectory option

21.0.1

@schematics/angular

Commit	Description
	add missing imports for lifecycle hooks in jasmine-vitest migration
	add mock names to createSpyObj transformation
	do not set esModuleInterop and moduleResolution when module is preserve
	fix migration of jasmine.clock().mockDate()
	handle createSpyObj without base name on refactor-jasmine-vitest
	improve safety of done callback transformation
	silently skip when the build target already uses one of the new builders
	support testRunner option in library schematic
	warn about loose matching in arrayWithExactContents

@angular/cli

Commit	Description
	ensure dependencies are resolved correctly for node modules directory check

@angular/build

Commit	Description
	correct Vitest coverage path resolution for JSDOM on Windows
	correctly configure per-browser headless mode in Vitest runner
	correctly invoke isTTY as a function
	ensure correct URL joining for prerender routes
	force dev-server to use HTTP/1.1 when using SSR with SSL
	normalize --include paths to posix

@angular/ssr

Commit	Description
	handle X-Forwarded-Prefix and APP_BASE_HREF in redirects
	prevent redirect loop with encoded query parameters

21.0.0

@angular/cli

Commit	Description
	add --json output to ng version
	add advanced filtering to MCP example search
	add ai-tutor mcp tool
	add builder info to list_projects MCP tool
	add fallback support for packages without direct ng add functionality
	add style language detection to list_projects tool
	add unit test framework detection to list_projects tool
	enhance ng version output with more details
	make documentation search tool version-aware
	make find_examples tool version-aware
	make get_best_practices tool version-aware
	overhaul ng version command output
	promote MCP find_examples tool to a stable tool
	provide detailed peer dependency conflict errors in ng add
	remove direct support for cnpm
	add schema versioning and metadata to example database
	add snippet support to example search MCP tool
	add vitest to version command output
	correct boolean parsing in MCP example front matter
	correct frontmatter parsing in MCP examples tool
	correct query in find_examples to prevent runtime error
	enhance find_examples MCP tool with structured output
	improve JSON schema parsing for command options
	improve list_projects MCP tool to find all workspaces in monorepos
	promote zoneless migration MCP tool to stable
	show planned actions in ng add dry run
	support multi-database search in find_examples MCP tool
	cache dependency lookups during ng add
	parallelize peer dependency checks in ng add

@schematics/angular

Commit	Description
	Add addTypeToClassName option to relevant schematics
	add include option to jasmine-to-vitest schematic
	add AGENTS.md support to ai-config schematic
	add Jasmine spy API transformations to jasmine-to-vitest schematic
	add matcher transformations to jasmine-to-vitest schematic
	add misc transformations to jasmine-to-vitest schematic
	add Tailwind CSS option to application schematic and ng new
	Applications are zoneless by default
	configure Vitest for new projects and allow runner choice
	introduce initial jasmine-to-vitest unit test refactor schematic
	set packageManager in package.json on new projects
	support different file name style guides in ng new
	add 'update-typescript-lib' migration
	add addImports option to jasmine-vitest schematic
	add fixture.whenStable in spec files when zoneless apps
	add migration to update moduleResolution to bundler
	add missing typeSeparator to main.ts.template file
	add Vitest config generation and runner checks
	add warnings and improve Karma config generation
	align Karma project generation with unified unit-test builder
	correct spacing in application spec tsconfig
	correct style guide paths for standalone components
	flag '--file-name-style-guide=2016' - wrong import in main.ts
	improve comment preservation in jasmine-to-vitest
	issues in apps generated with '--file-name-style-guide=2016' flag
	make ai-config schematic non-destructive
	preserve blank lines in jasmine-to-vitest schematic
	remove empty i18n-extract target for new projects
	remove explicit flag for host bindings
	remove extra space before async in spec templates
	respect skip-install for tailwind schematic
	transform Jasmine type annotations in jasmine-to-vitest schematic
	optimize AST traversal utilities

@angular-devkit/build-angular

Commit	Description
	ensure vitest code coverage handles virtual files correctly
	expand jest and jest-environment-jsdom to allow version 30
	make zone.js optional in server and app-shell builders

@angular/build

Commit	Description
	add --list-tests flag to unit-test builder
	add 'filter' option to unit-test builder
	add browserViewport option for vitest browser tests
	add advanced coverage options to unit-test builder
	add reporter output file option for unit-test
	allow options for unit test reporters
	support .test.ts files by default in unit test builder
	add --ui option for Vitest runner
	add define option to dev-server
	add temporary directory cleanup for Vitest executor
	add upfront dependency validation for unit-test runners
	add webcontainer support for Vitest browser provider
	allow globals to be set to false
	allow custom runner configuration file for unit-test
	allow unit-test progress option passthrough for building
	allow unit-test runner config with absolute path
	configure Vitest cache to use Angular cache
	correct Vitest builder watch mode execution
	correct Vitest coverage include handling for virtual files
	correct Vitest coverage reporting for test files
	correctly handle absolute paths and casing in test discovery
	direct check include file exists in unit-test discovery
	disable glob directory expansion when finding tests
	disable Vitest test isolation by default
	drop support for TypeScript 5.8
	dynamically select Vitest DOM environment
	enhance Vitest config merging and validation
	enhance Vitest dependency externalization and pre-bundling
	enhance Vitest resolution for optimal package loading
	ensure ɵgetOrCreateAngularServerApp is always defined after errors
	ensure TestBed cleanup hooks are always registered
	ensure TestBed setup is robust in non-isolated Vitest
	ensure Vitest setup files are executed in order
	exclude .angular from coverage instrumentation
	externalize Angular dependencies in Vitest runner
	improve error handling in unit-test builder
	introduce vitest-base.config for test configuration
	normalize paths for Vitest runner output files
	prioritize string type for runnerConfig schema
	provide default excludes for vitest coverage
	relax requirement for files to be in TS compilation
	remove deprecated javascriptEnabled option for Less
	remove explicit test isolation configuration
	resolve browser provider packages using project resolver
	resolve PostCSS plugins relative to config file
	serve build assets and styles in vitest
	set coverage report directory to coverage/project-name
	show full aggregate errors from vitest
	simplify SSL handling for ng serve with SSR (#31723)
	support ESM PostCSS plugins
	update vitest to 4.0.6 and remove coverage workaround

Breaking Changes

@angular/cli

• The ng commands will no longer automatically detect and use cnpm as the package manager. As an alternative use the .npmrc file to ensure npm uses the cnpm registry.

@angular/build

• TypeScript versions older than 5.9 are no longer supported.
• The javascriptEnabled option for Less is no longer supported. Projects relying on inline JavaScript within Less files will need to refactor their stylesheets to remove this dependency.

Does any of this look wrong? Please let us know.

See the full diff on Github. The new version differs by more commits than we can show here.

See the full diff on Github. The new version differs by more commits than we can show here.

7.28.5

v7.28.5 (2025-10-23)

Thank you @CO0Ki3, @Olexandr88, and @youthfulhps for your first PRs!

👓 Spec Compliance

• babel-parser
  • #17446 Allow Runtime Errors for Function Call Assignment Targets (@liuxingbaoyu)
• babel-helper-validator-identifier
  • #17501 fix: update identifier to unicode 17 (@fisker)

🐛 Bug Fix

• babel-plugin-proposal-destructuring-private
  • #17534 Allow mixing private destructuring and rest (@CO0Ki3)
• babel-parser
  • #17521 Improve @babel/parser error typing (@JLHwung)
  • #17491 fix: improve ts-only declaration parsing (@JLHwung)
• babel-plugin-proposal-discard-binding, babel-plugin-transform-destructuring
  • #17519 fix: rest correctly returns plain array (@liuxingbaoyu)
• babel-helper-create-class-features-plugin, babel-helper-member-expression-to-functions, babel-plugin-transform-block-scoping, babel-plugin-transform-optional-chaining, babel-traverse, babel-types
  • #17503 Fix JSXIdentifier handling in isReferencedIdentifier (@JLHwung)
• babel-traverse
  • #17504 fix: ensure scope.push register in anonymous fn (@JLHwung)

🏠 Internal

• babel-types
  • #17494 Type checking babel-types scripts (@JLHwung)

🏃‍♀️ Performance

• babel-core
  • #17490 Faster finding of locations in buildCodeFrameError (@liuxingbaoyu)

Committers: 8

• Babel Bot (@babel-bot)
• Byeongho Yoo (@youthfulhps)
• Huáng Jùnliàng (@JLHwung)
• Hyeon Dokko (@CO0Ki3)
• Nicolò Ribaudo (@nicolo-ribaudo)
• @Olexandr88
• @liuxingbaoyu
• fisker Cheung (@fisker)

Does any of this look wrong? Please let us know.

See the full diff on Github. The new version differs by more commits than we can show here.

7.28.5

v7.28.5 (2025-10-23)

Thank you @CO0Ki3, @Olexandr88, and @youthfulhps for your first PRs!

👓 Spec Compliance

• babel-parser
  • #17446 Allow Runtime Errors for Function Call Assignment Targets (@liuxingbaoyu)
• babel-helper-validator-identifier
  • #17501 fix: update identifier to unicode 17 (@fisker)

🐛 Bug Fix

• babel-plugin-proposal-destructuring-private
  • #17534 Allow mixing private destructuring and rest (@CO0Ki3)
• babel-parser
  • #17521 Improve @babel/parser error typing (@JLHwung)
  • #17491 fix: improve ts-only declaration parsing (@JLHwung)
• babel-plugin-proposal-discard-binding, babel-plugin-transform-destructuring
  • #17519 fix: rest correctly returns plain array (@liuxingbaoyu)
• babel-helper-create-class-features-plugin, babel-helper-member-expression-to-functions, babel-plugin-transform-block-scoping, babel-plugin-transform-optional-chaining, babel-traverse, babel-types
  • #17503 Fix JSXIdentifier handling in isReferencedIdentifier (@JLHwung)
• babel-traverse
  • #17504 fix: ensure scope.push register in anonymous fn (@JLHwung)

🏠 Internal

• babel-types
  • #17494 Type checking babel-types scripts (@JLHwung)

🏃‍♀️ Performance

• babel-core
  • #17490 Faster finding of locations in buildCodeFrameError (@liuxingbaoyu)

Committers: 8

• Babel Bot (@babel-bot)
• Byeongho Yoo (@youthfulhps)
• Huáng Jùnliàng (@JLHwung)
• Hyeon Dokko (@CO0Ki3)
• Nicolò Ribaudo (@nicolo-ribaudo)
• @Olexandr88
• @liuxingbaoyu
• fisker Cheung (@fisker)

Does any of this look wrong? Please let us know.

See the full diff on Github. The new version differs by more commits than we can show here.

7.28.5

v7.28.5 (2025-10-23)

Thank you @CO0Ki3, @Olexandr88, and @youthfulhps for your first PRs!

👓 Spec Compliance

• babel-parser
  • #17446 Allow Runtime Errors for Function Call Assignment Targets (@liuxingbaoyu)
• babel-helper-validator-identifier
  • #17501 fix: update identifier to unicode 17 (@fisker)

🐛 Bug Fix

• babel-plugin-proposal-destructuring-private
  • #17534 Allow mixing private destructuring and rest (@CO0Ki3)
• babel-parser
  • #17521 Improve @babel/parser error typing (@JLHwung)
  • #17491 fix: improve ts-only declaration parsing (@JLHwung)
• babel-plugin-proposal-discard-binding, babel-plugin-transform-destructuring
  • #17519 fix: rest correctly returns plain array (@liuxingbaoyu)
• babel-helper-create-class-features-plugin, babel-helper-member-expression-to-functions, babel-plugin-transform-block-scoping, babel-plugin-transform-optional-chaining, babel-traverse, babel-types
  • #17503 Fix JSXIdentifier handling in isReferencedIdentifier (@JLHwung)
• babel-traverse
  • #17504 fix: ensure scope.push register in anonymous fn (@JLHwung)

🏠 Internal

• babel-types
  • #17494 Type checking babel-types scripts (@JLHwung)

🏃‍♀️ Performance

• babel-core
  • #17490 Faster finding of locations in buildCodeFrameError (@liuxingbaoyu)

Committers: 8

• Babel Bot (@babel-bot)
• Byeongho Yoo (@youthfulhps)
• Huáng Jùnliàng (@JLHwung)
• Hyeon Dokko (@CO0Ki3)
• Nicolò Ribaudo (@nicolo-ribaudo)
• @Olexandr88
• @liuxingbaoyu
• fisker Cheung (@fisker)

Does any of this look wrong? Please let us know.

See the full diff on Github. The new version differs by more commits than we can show here.

See the full diff on Github. The new version differs by more commits than we can show here.

7.28.5

v7.28.5 (2025-10-23)

Thank you @CO0Ki3, @Olexandr88, and @youthfulhps for your first PRs!

👓 Spec Compliance

• babel-parser
  • #17446 Allow Runtime Errors for Function Call Assignment Targets (@liuxingbaoyu)
• babel-helper-validator-identifier
  • #17501 fix: update identifier to unicode 17 (@fisker)

🐛 Bug Fix

• babel-plugin-proposal-destructuring-private
  • #17534 Allow mixing private destructuring and rest (@CO0Ki3)
• babel-parser
  • #17521 Improve @babel/parser error typing (@JLHwung)
  • #17491 fix: improve ts-only declaration parsing (@JLHwung)
• babel-plugin-proposal-discard-binding, babel-plugin-transform-destructuring
  • #17519 fix: rest correctly returns plain array (@liuxingbaoyu)
• babel-helper-create-class-features-plugin, babel-helper-member-expression-to-functions, babel-plugin-transform-block-scoping, babel-plugin-transform-optional-chaining, babel-traverse, babel-types
  • #17503 Fix JSXIdentifier handling in isReferencedIdentifier (@JLHwung)
• babel-traverse
  • #17504 fix: ensure scope.push register in anonymous fn (@JLHwung)

🏠 Internal

• babel-types
  • #17494 Type checking babel-types scripts (@JLHwung)

🏃‍♀️ Performance

• babel-core
  • #17490 Faster finding of locations in buildCodeFrameError (@liuxingbaoyu)

Committers: 8

• Babel Bot (@babel-bot)
• Byeongho Yoo (@youthfulhps)
• Huáng Jùnliàng (@JLHwung)
• Hyeon Dokko (@CO0Ki3)
• Nicolò Ribaudo (@nicolo-ribaudo)
• @Olexandr88
• @liuxingbaoyu
• fisker Cheung (@fisker)

Does any of this look wrong? Please let us know.

See the full diff on Github. The new version differs by more commits than we can show here.

7.28.5

v7.28.5 (2025-10-23)

Thank you @CO0Ki3, @Olexandr88, and @youthfulhps for your first PRs!

👓 Spec Compliance

• babel-parser
  • #17446 Allow Runtime Errors for Function Call Assignment Targets (@liuxingbaoyu)
• babel-helper-validator-identifier
  • #17501 fix: update identifier to unicode 17 (@fisker)

🐛 Bug Fix

• babel-plugin-proposal-destructuring-private
  • #17534 Allow mixing private destructuring and rest (@CO0Ki3)
• babel-parser
  • #17521 Improve @babel/parser error typing (@JLHwung)
  • #17491 fix: improve ts-only declaration parsing (@JLHwung)
• babel-plugin-proposal-discard-binding, babel-plugin-transform-destructuring
  • #17519 fix: rest correctly returns plain array (@liuxingbaoyu)
• babel-helper-create-class-features-plugin, babel-helper-member-expression-to-functions, babel-plugin-transform-block-scoping, babel-plugin-transform-optional-chaining, babel-traverse, babel-types
  • #17503 Fix JSXIdentifier handling in isReferencedIdentifier (@JLHwung)
• babel-traverse
  • #17504 fix: ensure scope.push register in anonymous fn (@JLHwung)

🏠 Internal

• babel-types
  • #17494 Type checking babel-types scripts (@JLHwung)

🏃‍♀️ Performance

• babel-core
  • #17490 Faster finding of locations in buildCodeFrameError (@liuxingbaoyu)

Committers: 8

• Babel Bot (@babel-bot)
• Byeongho Yoo (@youthfulhps)
• Huáng Jùnliàng (@JLHwung)
• Hyeon Dokko (@CO0Ki3)
• Nicolò Ribaudo (@nicolo-ribaudo)
• @Olexandr88
• @liuxingbaoyu
• fisker Cheung (@fisker)

Does any of this look wrong? Please let us know.

See the full diff on Github. The new version differs by more commits than we can show here.

0.27.2

• Allow import path specifiers starting with #/ (#4361)

  Previously the specification for package.json disallowed import path specifiers starting with #/, but this restriction has recently been relaxed and support for it is being added across the JavaScript ecosystem. One use case is using it for a wildcard pattern such as mapping #/* to ./src/* (previously you had to use another character such as #_* instead, which was more confusing). There is some more context in nodejs/node#49182.

  This change was contributed by @hybrist.

• Automatically add the -webkit-mask prefix (#4357, #4358)

  This release automatically adds the -webkit- vendor prefix for the mask CSS shorthand property:

  /* Original code */
  main {
    mask: url(x.png) center/5rem no-repeat
  }
  
  /* Old output (with --target=chrome110) */
  main {
    mask: url(x.png) center/5rem no-repeat;
  }
  
  /* New output (with --target=chrome110) */
  main {
    -webkit-mask: url(x.png) center/5rem no-repeat;
    mask: url(x.png) center/5rem no-repeat;
  }

  This change was contributed by @BPJEnnova.

• Additional minification of switch statements (#4176, #4359)

  This release contains additional minification patterns for reducing switch statements. Here is an example:

  // Original code
  switch (x) {
    case 0:
      foo()
      break
    case 1:
    default:
      bar()
  }
  
  // Old output (with --minify)
  switch(x){case 0:foo();break;case 1:default:bar()}
  
  // New output (with --minify)
  x===0?foo():bar();

• Forbid using declarations inside switch clauses (#4323)

  This is a rare change to remove something that was previously possible. The Explicit Resource Management proposal introduced using declarations. These were previously allowed inside case and default clauses in switch statements. This had well-defined semantics and was already widely implemented (by V8, SpiderMonkey, TypeScript, esbuild, and others). However, it was considered to be too confusing because of how scope works in switch statements, so it has been removed from the specification. This edge case will now be a syntax error. See tc39/proposal-explicit-resource-management#215 and rbuckton/ecma262#14 for details.

  Here is an example of code that is no longer allowed:

  switch (mode) {
    case 'read':
      using readLock = db.read()
      return readAll(readLock)
  
    case 'write':
      using writeLock = db.write()
      return writeAll(writeLock)
  }

  That code will now have to be modified to look like this instead (note the additional { and } block statements around each case body):

  switch (mode) {
    case 'read': {
      using readLock = db.read()
      return readAll(readLock)
    }
    case 'write': {
      using writeLock = db.write()
      return writeAll(writeLock)
    }
  }

  This is not being released in one of esbuild's breaking change releases since this feature hasn't been finalized yet, and esbuild always tracks the current state of the specification (so esbuild's previous behavior was arguably incorrect).

0.27.1

• Fix bundler bug with var nested inside if (#4348)

  This release fixes a bug with the bundler that happens when importing an ES module using require (which causes it to be wrapped) and there's a top-level var inside an if statement without being wrapped in a { ... } block (and a few other conditions). The bundling transform needed to hoist these var declarations outside of the lazy ES module wrapper for correctness. See the issue for details.

• Fix minifier bug with for inside try inside label (#4351)

  This fixes an old regression from version v0.21.4. Some code was introduced to move the label inside the try statement to address a problem with transforming labeled for await loops to avoid the await (the transformation involves converting the for await loop into a for loop and wrapping it in a try statement). However, it introduces problems for cross-compiled JVM code that uses all three of these features heavily. This release restricts this transform to only apply to for loops that esbuild itself generates internally as part of the for await transform. Here is an example of some affected code:

  // Original code
  d: {
    e: {
      try {
        while (1) { break d }
      } catch { break e; }
    }
  }
  
  // Old output (with --minify)
  a:try{e:for(;;)break a}catch{break e}
  
  // New output (with --minify)
  a:e:try{for(;;)break a}catch{break e}

• Inline IIFEs containing a single expression (#4354)

  Previously inlining of IIFEs (immediately-invoked function expressions) only worked if the body contained a single return statement. Now it should also work if the body contains a single expression statement instead:

  // Original code
  const foo = () => {
    const cb = () => {
      console.log(x())
    }
    return cb()
  }
  
  // Old output (with --minify)
  const foo=()=>(()=>{console.log(x())})();
  
  // New output (with --minify)
  const foo=()=>{console.log(x())};

• The minifier now strips empty finally clauses (#4353)

  This improvement means that finally clauses containing dead code can potentially cause the associated try statement to be removed from the output entirely in minified builds:

  // Original code
  function foo(callback) {
    if (DEBUG) stack.push(callback.name);
    try {
      callback();
    } finally {
      if (DEBUG) stack.pop();
    }
  }
  
  // Old output (with --minify --define:DEBUG=false)
  function foo(a){try{a()}finally{}}
  
  // New output (with --minify --define:DEBUG=false)
  function foo(a){a()}

• Allow tree-shaking of the Symbol constructor

  With this release, calling Symbol is now considered to be side-effect free when the argument is known to be a primitive value. This means esbuild can now tree-shake module-level symbol variables:

  // Original code
  const a = Symbol('foo')
  const b = Symbol(bar)
  
  // Old output (with --tree-shaking=true)
  const a = Symbol("foo");
  const b = Symbol(bar);
  
  // New output (with --tree-shaking=true)
  const b = Symbol(bar);

0.27.0

This release deliberately contains backwards-incompatible changes. To avoid automatically picking up releases like this, you should either be pinning the exact version of esbuild in your package.json file (recommended) or be using a version range syntax that only accepts patch upgrades such as ^0.26.0 or ~0.26.0. See npm's documentation about semver for more information.

• Use Uint8Array.fromBase64 if available (#4286)

  With this release, esbuild's binary loader will now use the new Uint8Array.fromBase64 function unless it's unavailable in the configured target environment. If it's unavailable, esbuild's previous code for this will be used as a fallback. Note that this means you may now need to specify target when using this feature with Node (for example --target=node22) unless you're using Node v25+.

• Update the Go compiler from v1.23.12 to v1.25.4 (#4208, #4311)

  This raises the operating system requirements for running esbuild:

  • Linux: now requires a kernel version of 3.2 or later
  • macOS: now requires macOS 12 (Monterey) or later

0.26.0

• Enable trusted publishing (#4281)

  GitHub and npm are recommending that maintainers for packages such as esbuild switch to trusted publishing. With this release, a VM on GitHub will now build and publish all of esbuild's packages to npm instead of me. In theory.

  Unfortunately there isn't really a way to test that this works other than to do it live. So this release is that live test. Hopefully this release is uneventful and is exactly the same as the previous one (well, except for the green provenance attestation checkmark on npm that happens with trusted publishing).

0.25.12

• Fix a minification regression with CSS media queries (#4315)

  The previous release introduced support for parsing media queries which unintentionally introduced a regression with the removal of duplicate media rules during minification. Specifically the grammar for @media <media-type> and <media-condition-without-or> { ... } was missing an equality check for the <media-condition-without-or> part, so rules with different suffix clauses in this position would incorrectly compare equal and be deduplicated. This release fixes the regression.

• Update the list of known JavaScript globals (#4310)

  This release updates esbuild's internal list of known JavaScript globals. These are globals that are known to not have side-effects when the property is accessed. For example, accessing the global Array property is considered to be side-effect free but accessing the global scrollY property can trigger a layout, which is a side-effect. This is used by esbuild's tree-shaking to safely remove unused code that is known to be side-effect free. This update adds the following global properties:

  From ES2017:

  • Atomics
  • SharedArrayBuffer

  From ES2020:

  • BigInt64Array
  • BigUint64Array

  From ES2021:

  • FinalizationRegistry
  • WeakRef

  From ES2025:

  • Float16Array
  • Iterator

  Note that this does not indicate that constructing any of these objects is side-effect free, just that accessing the identifier is side-effect free. For example, this now allows esbuild to tree-shake classes that extend from Iterator:

  // This can now be tree-shaken by esbuild:
  class ExampleIterator extends Iterator {}

• Add support for the new @view-transition CSS rule (#4313)

  With this release, esbuild now has improved support for pretty-printing and minifying the new @view-transition rule (which esbuild was previously unaware of):

  /* Original code */
  @view-transition {
    navigation: auto;
    types: check;
  }
  
  /* Old output */
  @view-transition { navigation: auto; types: check; }
  
  /* New output */
  @view-transition {
    navigation: auto;
    types: check;
  }

  The new view transition feature provides a mechanism for creating animated transitions between documents in a multi-page app. You can read more about view transition rules here.

  This change was contributed by @yisibl.

• Trim CSS rules that will never match

  The CSS minifier will now remove rules whose selectors contain :is() and :where() as those selectors will never match. These selectors can currently be automatically generated by esbuild when you give esbuild nonsensical input such as the following:

  /* Original code */
  div:before {
    color: green;
    &.foo {
      color: red;
    }
  }
  
  /* Old output (with --supported:nesting=false --minify) */
  div:before{color:green}:is().foo{color:red}
  
  /* New output (with --supported:nesting=false --minify) */
  div:before{color:green}

  This input is nonsensical because CSS nesting is (unfortunately) not supported inside of pseudo-elements such as :before. Currently esbuild generates a rule containing :is() in this case when you tell esbuild to transform nested CSS into non-nested CSS. I think it's reasonable to do that as it sort of helps explain what's going on (or at least indicates that something is wrong in the output). It shouldn't be present in minified code, however, so this release now strips it out.

0.25.11

• Add support for with { type: 'bytes' } imports (#4292)

  The import bytes proposal has reached stage 2.7 in the TC39 process, which means that although it isn't quite recommended for implementation, it's generally approved and ready for validation. Furthermore it has already been implemented by Deno and Webpack. So with this release, esbuild will also add support for this. It behaves exactly the same as esbuild's existing binary loader. Here's an example:

  import data from './image.png' with { type: 'bytes' }
  const view = new DataView(data.buffer, 0, 24)
  const width = view.getInt32(16)
  const height = view.getInt32(20)
  console.log('size:', width + '\xD7' + height)

• Lower CSS media query range syntax (#3748, #4293)

  With this release, esbuild will now transform CSS media query range syntax into equivalent syntax using min-/max- prefixes for older browsers. For example, the following CSS:

  @media (640px <= width <= 960px) {
    main {
      display: flex;
    }
  }

  will be transformed like this with a target such as --target=chrome100 (or more specifically with --supported:media-range=false if desired):

  @media (min-width: 640px) and (max-width: 960px) {
    main {
      display: flex;
    }
  }

0.25.10

• Fix a panic in a minification edge case (#4287)

  This release fixes a panic due to a null pointer that could happen when esbuild inlines a doubly-nested identity function and the final result is empty. It was fixed by emitting the value undefined in this case, which avoids the panic. This case must be rare since it hasn't come up until now. Here is an example of code that previously triggered the panic (which only happened when minifying):

  function identity(x) { return x }
  identity({ y: identity(123) })

• Fix @supports nested inside pseudo-element (#4265)

  When transforming nested CSS to non-nested CSS, esbuild is supposed to filter out pseudo-elements such as ::placeholder for correctness. The CSS nesting specification says the following:

  The nesting selector cannot represent pseudo-elements (identical to the behavior of the ':is()' pseudo-class). We’d like to relax this restriction, but need to do so simultaneously for both ':is()' and '&', since they’re intentionally built on the same underlying mechanisms.

  However, it seems like this behavior is different for nested at-rules such as @supports, which do work with pseudo-elements. So this release modifies esbuild's behavior to now take that into account:

  /* Original code */
  ::placeholder {
    color: red;
    body & { color: green }
    @supports (color: blue) { color: blue }
  }
  
  /* Old output (with --supported:nesting=false) */
  ::placeholder {
    color: red;
  }
  body :is() {
    color: green;
  }
  @supports (color: blue) {
     {
      color: blue;
    }
  }
  
  /* New output (with --supported:nesting=false) */
  ::placeholder {
    color: red;
  }
  body :is() {
    color: green;
  }
  @supports (color: blue) {
    ::placeholder {
      color: blue;
    }
  }

Does any of this look wrong? Please let us know.

See the full diff on Github. The new version differs by 64 commits:

• publish 0.27.2 to npm
• additional tests for `switch` with `break`
• update release notes
• fix #4357: -webkit- prefix for mask shorthand (#4358)
• compat table: update `@types/node`
• compat table: fix a type error with the new types
• fix `make compat-table` to install dependencies
• release notes for #4361
• fix: allow subpath imports that start with `#/` (#4361)
• minify some switch statements to if-else statement
• fix #4176: improve switch statement partial-eval
• introduce more helper methods
• fix some extremely subtle switch minification bugs
• introduce a helper method
• fix #4359: prune empty `case` before a `default`
• fix #4323: forbid `using` inside `switch` clauses
• close #4362, close #4363: update to go 1.25.5
• publish 0.27.1 to npm
• fix #4354: improve IIFE inlining for expressions
• minify: move unused expr simplification later
• fix #4353: remove empty `try`/`finally` clauses
• fix #4348: bundler bug with `var` inside `if`
• fix #4351: label + `try` + `for` minifier bug
• fix: deno release url wrong comment (#4326)
• calling `Symbol.for` with a primitive never throws
• update `decorator-tests.js` snapshot
• calling `Symbol` with a primitive will never throw
• publish 0.27.0 to npm
• fix #4286: use `Uint8Array.fromBase64` if present (#4295)
• update go 1.25.3 => 1.25.4
• update go 1.23.12 => 1.25.3 (#4318)
• use a patched go compiler for release builds
• delete temporary `release.yml` workflow
• add a temporary `release.yml` workflow
• fix `publish.yml`
• publish 0.26.0 to npm
• enable trusted publishing (#4319)
• some deno-related fixes
• add a dummy `publish.yml`
• publish 0.25.12 to npm
• update release notes
• minify: remove css rules containing empty `:is()`
• add some additional known static methods
• automatically mark "RegExp.escape()" calls as pure
• simplify some call expression checks
• add some additional known static methods
• fix #4310: add `Iterator` and other known globals
• fix: escape dev server breadcrumb hrefs properly (#4316)
• fix #4315: `@media` deduplication bug edge case
• update release notes
• feat: add CSS `@view-transition` (#4313)
• publish 0.25.11 to npm
• css: also parse media queries in `@import` rules
• css: some adjustments to `@import` parsing
• fix #3748, fix #4293: lower css media range syntax
• css: parse and print media queries
• run `make update-compat-table`
• fix #4292: support `with { type: bytes }`
• publish 0.25.10 to npm
• refactor: use strings.Builder (#4290)
• run `make update-compat-table`
• fix #4287: marked the wrong issue as fixed
• fix #4286: minifier panic due to identity function
• fix #4265: `@supports` nested inside `::pseudo`

0.27.2

• Allow import path specifiers starting with #/ (#4361)

  Previously the specification for package.json disallowed import path specifiers starting with #/, but this restriction has recently been relaxed and support for it is being added across the JavaScript ecosystem. One use case is using it for a wildcard pattern such as mapping #/* to ./src/* (previously you had to use another character such as #_* instead, which was more confusing). There is some more context in nodejs/node#49182.

  This change was contributed by @hybrist.

• Automatically add the -webkit-mask prefix (#4357, #4358)

  This release automatically adds the -webkit- vendor prefix for the mask CSS shorthand property:

  /* Original code */
  main {
    mask: url(x.png) center/5rem no-repeat
  }
  
  /* Old output (with --target=chrome110) */
  main {
    mask: url(x.png) center/5rem no-repeat;
  }
  
  /* New output (with --target=chrome110) */
  main {
    -webkit-mask: url(x.png) center/5rem no-repeat;
    mask: url(x.png) center/5rem no-repeat;
  }

  This change was contributed by @BPJEnnova.

• Additional minification of switch statements (#4176, #4359)

  This release contains additional minification patterns for reducing switch statements. Here is an example:

  // Original code
  switch (x) {
    case 0:
      foo()
      break
    case 1:
    default:
      bar()
  }
  
  // Old output (with --minify)
  switch(x){case 0:foo();break;case 1:default:bar()}
  
  // New output (with --minify)
  x===0?foo():bar();

• Forbid using declarations inside switch clauses (#4323)

  This is a rare change to remove something that was previously possible. The Explicit Resource Management proposal introduced using declarations. These were previously allowed inside case and default clauses in switch statements. This had well-defined semantics and was already widely implemented (by V8, SpiderMonkey, TypeScript, esbuild, and others). However, it was considered to be too confusing because of how scope works in switch statements, so it has been removed from the specification. This edge case will now be a syntax error. See tc39/proposal-explicit-resource-management#215 and rbuckton/ecma262#14 for details.

  Here is an example of code that is no longer allowed:

  switch (mode) {
    case 'read':
      using readLock = db.read()
      return readAll(readLock)
  
    case 'write':
      using writeLock = db.write()
      return writeAll(writeLock)
  }

  That code will now have to be modified to look like this instead (note the additional { and } block statements around each case body):

  switch (mode) {
    case 'read': {
      using readLock = db.read()
      return readAll(readLock)
    }
    case 'write': {
      using writeLock = db.write()
      return writeAll(writeLock)
    }
  }

  This is not being released in one of esbuild's breaking change releases since this feature hasn't been finalized yet, and esbuild always tracks the current state of the specification (so esbuild's previous behavior was arguably incorrect).

0.27.1

• Fix bundler bug with var nested inside if (#4348)

  This release fixes a bug with the bundler that happens when importing an ES module using require (which causes it to be wrapped) and there's a top-level var inside an if statement without being wrapped in a { ... } block (and a few other conditions). The bundling transform needed to hoist these var declarations outside of the lazy ES module wrapper for correctness. See the issue for details.

• Fix minifier bug with for inside try inside label (#4351)

  This fixes an old regression from version v0.21.4. Some code was introduced to move the label inside the try statement to address a problem with transforming labeled for await loops to avoid the await (the transformation involves converting the for await loop into a for loop and wrapping it in a try statement). However, it introduces problems for cross-compiled JVM code that uses all three of these features heavily. This release restricts this transform to only apply to for loops that esbuild itself generates internally as part of the for await transform. Here is an example of some affected code:

  // Original code
  d: {
    e: {
      try {
        while (1) { break d }
      } catch { break e; }
    }
  }
  
  // Old output (with --minify)
  a:try{e:for(;;)break a}catch{break e}
  
  // New output (with --minify)
  a:e:try{for(;;)break a}catch{break e}

• Inline IIFEs containing a single expression (#4354)

  Previously inlining of IIFEs (immediately-invoked function expressions) only worked if the body contained a single return statement. Now it should also work if the body contains a single expression statement instead:

  // Original code
  const foo = () => {
    const cb = () => {
      console.log(x())
    }
    return cb()
  }
  
  // Old output (with --minify)
  const foo=()=>(()=>{console.log(x())})();
  
  // New output (with --minify)
  const foo=()=>{console.log(x())};

• The minifier now strips empty finally clauses (#4353)

  This improvement means that finally clauses containing dead code can potentially cause the associated try statement to be removed from the output entirely in minified builds:

  // Original code
  function foo(callback) {
    if (DEBUG) stack.push(callback.name);
    try {
      callback();
    } finally {
      if (DEBUG) stack.pop();
    }
  }
  
  // Old output (with --minify --define:DEBUG=false)
  function foo(a){try{a()}finally{}}
  
  // New output (with --minify --define:DEBUG=false)
  function foo(a){a()}

• Allow tree-shaking of the Symbol constructor

  With this release, calling Symbol is now considered to be side-effect free when the argument is known to be a primitive value. This means esbuild can now tree-shake module-level symbol variables:

  // Original code
  const a = Symbol('foo')
  const b = Symbol(bar)
  
  // Old output (with --tree-shaking=true)
  const a = Symbol("foo");
  const b = Symbol(bar);
  
  // New output (with --tree-shaking=true)
  const b = Symbol(bar);

0.27.0

This release deliberately contains backwards-incompatible changes. To avoid automatically picking up releases like this, you should either be pinning the exact version of esbuild in your package.json file (recommended) or be using a version range syntax that only accepts patch upgrades such as ^0.26.0 or ~0.26.0. See npm's documentation about semver for more information.

• Use Uint8Array.fromBase64 if available (#4286)

  With this release, esbuild's binary loader will now use the new Uint8Array.fromBase64 function unless it's unavailable in the configured target environment. If it's unavailable, esbuild's previous code for this will be used as a fallback. Note that this means you may now need to specify target when using this feature with Node (for example --target=node22) unless you're using Node v25+.

• Update the Go compiler from v1.23.12 to v1.25.4 (#4208, #4311)

  This raises the operating system requirements for running esbuild:

  • Linux: now requires a kernel version of 3.2 or later
  • macOS: now requires macOS 12 (Monterey) or later

0.26.0

• Enable trusted publishing (#4281)

  GitHub and npm are recommending that maintainers for packages such as esbuild switch to trusted publishing. With this release, a VM on GitHub will now build and publish all of esbuild's packages to npm instead of me. In theory.

  Unfortunately there isn't really a way to test that this works other than to do it live. So this release is that live test. Hopefully this release is uneventful and is exactly the same as the previous one (well, except for the green provenance attestation checkmark on npm that happens with trusted publishing).

0.25.12

• Fix a minification regression with CSS media queries (#4315)

  The previous release introduced support for parsing media queries which unintentionally introduced a regression with the removal of duplicate media rules during minification. Specifically the grammar for @media <media-type> and <media-condition-without-or> { ... } was missing an equality check for the <media-condition-without-or> part, so rules with different suffix clauses in this position would incorrectly compare equal and be deduplicated. This release fixes the regression.

• Update the list of known JavaScript globals (#4310)

  This release updates esbuild's internal list of known JavaScript globals. These are globals that are known to not have side-effects when the property is accessed. For example, accessing the global Array property is considered to be side-effect free but accessing the global scrollY property can trigger a layout, which is a side-effect. This is used by esbuild's tree-shaking to safely remove unused code that is known to be side-effect free. This update adds the following global properties:

  From ES2017:

  • Atomics
  • SharedArrayBuffer

  From ES2020:

  • BigInt64Array
  • BigUint64Array

  From ES2021:

  • FinalizationRegistry
  • WeakRef

  From ES2025:

  • Float16Array
  • Iterator

  Note that this does not indicate that constructing any of these objects is side-effect free, just that accessing the identifier is side-effect free. For example, this now allows esbuild to tree-shake classes that extend from Iterator:

  // This can now be tree-shaken by esbuild:
  class ExampleIterator extends Iterator {}

• Add support for the new @view-transition CSS rule (#4313)

  With this release, esbuild now has improved support for pretty-printing and minifying the new @view-transition rule (which esbuild was previously unaware of):

  /* Original code */
  @view-transition {
    navigation: auto;
    types: check;
  }
  
  /* Old output */
  @view-transition { navigation: auto; types: check; }
  
  /* New output */
  @view-transition {
    navigation: auto;
    types: check;
  }

  The new view transition feature provides a mechanism for creating animated transitions between documents in a multi-page app. You can read more about view transition rules here.

  This change was contributed by @yisibl.

• Trim CSS rules that will never match

  The CSS minifier will now remove rules whose selectors contain :is() and :where() as those selectors will never match. These selectors can currently be automatically generated by esbuild when you give esbuild nonsensical input such as the following:

  /* Original code */
  div:before {
    color: green;
    &.foo {
      color: red;
    }
  }
  
  /* Old output (with --supported:nesting=false --minify) */
  div:before{color:green}:is().foo{color:red}
  
  /* New output (with --supported:nesting=false --minify) */
  div:before{color:green}

  This input is nonsensical because CSS nesting is (unfortunately) not supported inside of pseudo-elements such as :before. Currently esbuild generates a rule containing :is() in this case when you tell esbuild to transform nested CSS into non-nested CSS. I think it's reasonable to do that as it sort of helps explain what's going on (or at least indicates that something is wrong in the output). It shouldn't be present in minified code, however, so this release now strips it out.

0.25.11

• Add support for with { type: 'bytes' } imports (#4292)

  The import bytes proposal has reached stage 2.7 in the TC39 process, which means that although it isn't quite recommended for implementation, it's generally approved and ready for validation. Furthermore it has already been implemented by Deno and Webpack. So with this release, esbuild will also add support for this. It behaves exactly the same as esbuild's existing binary loader. Here's an example:

  import data from './image.png' with { type: 'bytes' }
  const view = new DataView(data.buffer, 0, 24)
  const width = view.getInt32(16)
  const height = view.getInt32(20)
  console.log('size:', width + '\xD7' + height)

• Lower CSS media query range syntax (#3748, #4293)

  With this release, esbuild will now transform CSS media query range syntax into equivalent syntax using min-/max- prefixes for older browsers. For example, the following CSS:

  @media (640px <= width <= 960px) {
    main {
      display: flex;
    }
  }

  will be transformed like this with a target such as --target=chrome100 (or more specifically with --supported:media-range=false if desired):

  @media (min-width: 640px) and (max-width: 960px) {
    main {
      display: flex;
    }
  }

0.25.10

• Fix a panic in a minification edge case (#4287)

  This release fixes a panic due to a null pointer that could happen when esbuild inlines a doubly-nested identity function and the final result is empty. It was fixed by emitting the value undefined in this case, which avoids the panic. This case must be rare since it hasn't come up until now. Here is an example of code that previously triggered the panic (which only happened when minifying):

  function identity(x) { return x }
  identity({ y: identity(123) })

• Fix @supports nested inside pseudo-element (#4265)

  When transforming nested CSS to non-nested CSS, esbuild is supposed to filter out pseudo-elements such as ::placeholder for correctness. The CSS nesting specification says the following:

  The nesting selector cannot represent pseudo-elements (identical to the behavior of the ':is()' pseudo-class). We’d like to relax this restriction, but need to do so simultaneously for both ':is()' and '&', since they’re intentionally built on the same underlying mechanisms.

  However, it seems like this behavior is different for nested at-rules such as @supports, which do work with pseudo-elements. So this release modifies esbuild's behavior to now take that into account:

  /* Original code */
  ::placeholder {
    color: red;
    body & { color: green }
    @supports (color: blue) { color: blue }
  }
  
  /* Old output (with --supported:nesting=false) */
  ::placeholder {
    color: red;
  }
  body :is() {
    color: green;
  }
  @supports (color: blue) {
     {
      color: blue;
    }
  }
  
  /* New output (with --supported:nesting=false) */
  ::placeholder {
    color: red;
  }
  body :is() {
    color: green;
  }
  @supports (color: blue) {
    ::placeholder {
      color: blue;
    }
  }

Does any of this look wrong? Please let us know.

See the full diff on Github. The new version differs by 64 commits:

• publish 0.27.2 to npm
• additional tests for `switch` with `break`
• update release notes
• fix #4357: -webkit- prefix for mask shorthand (#4358)
• compat table: update `@types/node`
• compat table: fix a type error with the new types
• fix `make compat-table` to install dependencies
• release notes for #4361
• fix: allow subpath imports that start with `#/` (#4361)
• minify some switch statements to if-else statement
• fix #4176: improve switch statement partial-eval
• introduce more helper methods
• fix some extremely subtle switch minification bugs
• introduce a helper method
• fix #4359: prune empty `case` before a `default`
• fix #4323: forbid `using` inside `switch` clauses
• close #4362, close #4363: update to go 1.25.5
• publish 0.27.1 to npm
• fix #4354: improve IIFE inlining for expressions
• minify: move unused expr simplification later
• fix #4353: remove empty `try`/`finally` clauses
• fix #4348: bundler bug with `var` inside `if`
• fix #4351: label + `try` + `for` minifier bug
• fix: deno release url wrong comment (#4326)
• calling `Symbol.for` with a primitive never throws
• update `decorator-tests.js` snapshot
• calling `Symbol` with a primitive will never throw
• publish 0.27.0 to npm
• fix #4286: use `Uint8Array.fromBase64` if present (#4295)
• update go 1.25.3 => 1.25.4
• update go 1.23.12 => 1.25.3 (#4318)
• use a patched go compiler for release builds
• delete temporary `release.yml` workflow
• add a temporary `release.yml` workflow
• fix `publish.yml`
• publish 0.26.0 to npm
• enable trusted publishing (#4319)
• some deno-related fixes
• add a dummy `publish.yml`
• publish 0.25.12 to npm
• update release notes
• minify: remove css rules containing empty `:is()`
• add some additional known static methods
• automatically mark "RegExp.escape()" calls as pure
• simplify some call expression checks
• add some additional known static methods
• fix #4310: add `Iterator` and other known globals
• fix: escape dev server breadcrumb hrefs properly (#4316)
• fix #4315: `@media` deduplication bug edge case
• update release notes
• feat: add CSS `@view-transition` (#4313)
• publish 0.25.11 to npm
• css: also parse media queries in `@import` rules
• css: some adjustments to `@import` parsing
• fix #3748, fix #4293: lower css media range syntax
• css: parse and print media queries
• run `make update-compat-table`
• fix #4292: support `with { type: bytes }`
• publish 0.25.10 to npm
• refactor: use strings.Builder (#4290)
• run `make update-compat-table`
• fix #4287: marked the wrong issue as fixed
• fix #4286: minifier panic due to identity function
• fix #4265: `@supports` nested inside `::pseudo`

0.27.2

• Allow import path specifiers starting with #/ (#4361)

  Previously the specification for package.json disallowed import path specifiers starting with #/, but this restriction has recently been relaxed and support for it is being added across the JavaScript ecosystem. One use case is using it for a wildcard pattern such as mapping #/* to ./src/* (previously you had to use another character such as #_* instead, which was more confusing). There is some more context in nodejs/node#49182.

  This change was contributed by @hybrist.

• Automatically add the -webkit-mask prefix (#4357, #4358)

  This release automatically adds the -webkit- vendor prefix for the mask CSS shorthand property:

  /* Original code */
  main {
    mask: url(x.png) center/5rem no-repeat
  }
  
  /* Old output (with --target=chrome110) */
  main {
    mask: url(x.png) center/5rem no-repeat;
  }
  
  /* New output (with --target=chrome110) */
  main {
    -webkit-mask: url(x.png) center/5rem no-repeat;
    mask: url(x.png) center/5rem no-repeat;
  }

  This change was contributed by @BPJEnnova.

• Additional minification of switch statements (#4176, #4359)

  This release contains additional minification patterns for reducing switch statements. Here is an example:

  // Original code
  switch (x) {
    case 0:
      foo()
      break
    case 1:
    default:
      bar()
  }
  
  // Old output (with --minify)
  switch(x){case 0:foo();break;case 1:default:bar()}
  
  // New output (with --minify)
  x===0?foo():bar();

• Forbid using declarations inside switch clauses (#4323)

  This is a rare change to remove something that was previously possible. The Explicit Resource Management proposal introduced using declarations. These were previously allowed inside case and default clauses in switch statements. This had well-defined semantics and was already widely implemented (by V8, SpiderMonkey, TypeScript, esbuild, and others). However, it was considered to be too confusing because of how scope works in switch statements, so it has been removed from the specification. This edge case will now be a syntax error. See tc39/proposal-explicit-resource-management#215 and rbuckton/ecma262#14 for details.

  Here is an example of code that is no longer allowed:

  switch (mode) {
    case 'read':
      using readLock = db.read()
      return readAll(readLock)
  
    case 'write':
      using writeLock = db.write()
      return writeAll(writeLock)
  }

  That code will now have to be modified to look like this instead (note the additional { and } block statements around each case body):

  switch (mode) {
    case 'read': {
      using readLock = db.read()
      return readAll(readLock)
    }
    case 'write': {
      using writeLock = db.write()
      return writeAll(writeLock)
    }
  }

  This is not being released in one of esbuild's breaking change releases since this feature hasn't been finalized yet, and esbuild always tracks the current state of the specification (so esbuild's previous behavior was arguably incorrect).

0.27.1

• Fix bundler bug with var nested inside if (#4348)

  This release fixes a bug with the bundler that happens when importing an ES module using require (which causes it to be wrapped) and there's a top-level var inside an if statement without being wrapped in a { ... } block (and a few other conditions). The bundling transform needed to hoist these var declarations outside of the lazy ES module wrapper for correctness. See the issue for details.

• Fix minifier bug with for inside try inside label (#4351)

  This fixes an old regression from version v0.21.4. Some code was introduced to move the label inside the try statement to address a problem with transforming labeled for await loops to avoid the await (the transformation involves converting the for await loop into a for loop and wrapping it in a try statement). However, it introduces problems for cross-compiled JVM code that uses all three of these features heavily. This release restricts this transform to only apply to for loops that esbuild itself generates internally as part of the for await transform. Here is an example of some affected code:

  // Original code
  d: {
    e: {
      try {
        while (1) { break d }
      } catch { break e; }
    }
  }
  
  // Old output (with --minify)
  a:try{e:for(;;)break a}catch{break e}
  
  // New output (with --minify)
  a:e:try{for(;;)break a}catch{break e}

• Inline IIFEs containing a single expression (#4354)

  Previously inlining of IIFEs (immediately-invoked function expressions) only worked if the body contained a single return statement. Now it should also work if the body contains a single expression statement instead:

  // Original code
  const foo = () => {
    const cb = () => {
      console.log(x())
    }
    return cb()
  }
  
  // Old output (with --minify)
  const foo=()=>(()=>{console.log(x())})();
  
  // New output (with --minify)
  const foo=()=>{console.log(x())};

• The minifier now strips empty finally clauses (#4353)

  This improvement means that finally clauses containing dead code can potentially cause the associated try statement to be removed from the output entirely in minified builds:

  // Original code
  function foo(callback) {
    if (DEBUG) stack.push(callback.name);
    try {
      callback();
    } finally {
      if (DEBUG) stack.pop();
    }
  }
  
  // Old output (with --minify --define:DEBUG=false)
  function foo(a){try{a()}finally{}}
  
  // New output (with --minify --define:DEBUG=false)
  function foo(a){a()}

• Allow tree-shaking of the Symbol constructor

  With this release, calling Symbol is now considered to be side-effect free when the argument is known to be a primitive value. This means esbuild can now tree-shake module-level symbol variables:

  // Original code
  const a = Symbol('foo')
  const b = Symbol(bar)
  
  // Old output (with --tree-shaking=true)
  const a = Symbol("foo");
  const b = Symbol(bar);
  
  // New output (with --tree-shaking=true)
  const b = Symbol(bar);

0.27.0

This release deliberately contains backwards-incompatible changes. To avoid automatically picking up releases like this, you should either be pinning the exact version of esbuild in your package.json file (recommended) or be using a version range syntax that only accepts patch upgrades such as ^0.26.0 or ~0.26.0. See npm's documentation about semver for more information.

• Use Uint8Array.fromBase64 if available (#4286)

  With this release, esbuild's binary loader will now use the new Uint8Array.fromBase64 function unless it's unavailable in the configured target environment. If it's unavailable, esbuild's previous code for this will be used as a fallback. Note that this means you may now need to specify target when using this feature with Node (for example --target=node22) unless you're using Node v25+.

• Update the Go compiler from v1.23.12 to v1.25.4 (#4208, #4311)

  This raises the operating system requirements for running esbuild:

  • Linux: now requires a kernel version of 3.2 or later
  • macOS: now requires macOS 12 (Monterey) or later

0.26.0

• Enable trusted publishing (#4281)

  GitHub and npm are recommending that maintainers for packages such as esbuild switch to trusted publishing. With this release, a VM on GitHub will now build and publish all of esbuild's packages to npm instead of me. In theory.

  Unfortunately there isn't really a way to test that this works other than to do it live. So this release is that live test. Hopefully this release is uneventful and is exactly the same as the previous one (well, except for the green provenance attestation checkmark on npm that happens with trusted publishing).

0.25.12

• Fix a minification regression with CSS media queries (#4315)

  The previous release introduced support for parsing media queries which unintentionally introduced a regression with the removal of duplicate media rules during minification. Specifically the grammar for @media <media-type> and <media-condition-without-or> { ... } was missing an equality check for the <media-condition-without-or> part, so rules with different suffix clauses in this position would incorrectly compare equal and be deduplicated. This release fixes the regression.

• Update the list of known JavaScript globals (#4310)

  This release updates esbuild's internal list of known JavaScript globals. These are globals that are known to not have side-effects when the property is accessed. For example, accessing the global Array property is considered to be side-effect free but accessing the global scrollY property can trigger a layout, which is a side-effect. This is used by esbuild's tree-shaking to safely remove unused code that is known to be side-effect free. This update adds the following global properties:

  From ES2017:

  • Atomics
  • SharedArrayBuffer

  From ES2020:

  • BigInt64Array
  • BigUint64Array

  From ES2021:

  • FinalizationRegistry
  • WeakRef

  From ES2025:

  • Float16Array
  • Iterator

  Note that this does not indicate that constructing any of these objects is side-effect free, just that accessing the identifier is side-effect free. For example, this now allows esbuild to tree-shake classes that extend from Iterator:

  // This can now be tree-shaken by esbuild:
  class ExampleIterator extends Iterator {}

• Add support for the new @view-transition CSS rule (#4313)

  With this release, esbuild now has improved support for pretty-printing and minifying the new @view-transition rule (which esbuild was previously unaware of):

  /* Original code */
  @view-transition {
    navigation: auto;
    types: check;
  }
  
  /* Old output */
  @view-transition { navigation: auto; types: check; }
  
  /* New output */
  @view-transition {
    navigation: auto;
    types: check;
  }

  The new view transition feature provides a mechanism for creating animated transitions between documents in a multi-page app. You can read more about view transition rules here.

  This change was contributed by @yisibl.

• Trim CSS rules that will never match

  The CSS minifier will now remove rules whose selectors contain :is() and :where() as those selectors will never match. These selectors can currently be automatically generated by esbuild when you give esbuild nonsensical input such as the following:

  /* Original code */
  div:before {
    color: green;
    &.foo {
      color: red;
    }
  }
  
  /* Old output (with --supported:nesting=false --minify) */
  div:before{color:green}:is().foo{color:red}
  
  /* New output (with --supported:nesting=false --minify) */
  div:before{color:green}

  This input is nonsensical because CSS nesting is (unfortunately) not supported inside of pseudo-elements such as :before. Currently esbuild generates a rule containing :is() in this case when you tell esbuild to transform nested CSS into non-nested CSS. I think it's reasonable to do that as it sort of helps explain what's going on (or at least indicates that something is wrong in the output). It shouldn't be present in minified code, however, so this release now strips it out.

0.25.11

• Add support for with { type: 'bytes' } imports (#4292)

  The import bytes proposal has reached stage 2.7 in the TC39 process, which means that although it isn't quite recommended for implementation, it's generally approved and ready for validation. Furthermore it has already been implemented by Deno and Webpack. So with this release, esbuild will also add support for this. It behaves exactly the same as esbuild's existing binary loader. Here's an example:

  import data from './image.png' with { type: 'bytes' }
  const view = new DataView(data.buffer, 0, 24)
  const width = view.getInt32(16)
  const height = view.getInt32(20)
  console.log('size:', width + '\xD7' + height)

• Lower CSS media query range syntax (#3748, #4293)

  With this release, esbuild will now transform CSS media query range syntax into equivalent syntax using min-/max- prefixes for older browsers. For example, the following CSS:

  @media (640px <= width <= 960px) {
    main {
      display: flex;
    }
  }

  will be transformed like this with a target such as --target=chrome100 (or more specifically with --supported:media-range=false if desired):

  @media (min-width: 640px) and (max-width: 960px) {
    main {
      display: flex;
    }
  }

0.25.10

• Fix a panic in a minification edge case (#4287)

  This release fixes a panic due to a null pointer that could happen when esbuild inlines a doubly-nested identity function and the final result is empty. It was fixed by emitting the value undefined in this case, which avoids the panic. This case must be rare since it hasn't come up until now. Here is an example of code that previously triggered the panic (which only happened when minifying):

  function identity(x) { return x }
  identity({ y: identity(123) })

• Fix @supports nested inside pseudo-element (#4265)

  When transforming nested CSS to non-nested CSS, esbuild is supposed to filter out pseudo-elements such as ::placeholder for correctness. The CSS nesting specification says the following:

  The nesting selector cannot represent pseudo-elements (identical to the behavior of the ':is()' pseudo-class). We’d like to relax this restriction, but need to do so simultaneously for both ':is()' and '&', since they’re intentionally built on the same underlying mechanisms.

  However, it seems like this behavior is different for nested at-rules such as @supports, which do work with pseudo-elements. So this release modifies esbuild's behavior to now take that into account:

  /* Original code */
  ::placeholder {
    color: red;
    body & { color: green }
    @supports (color: blue) { color: blue }
  }
  
  /* Old output (with --supported:nesting=false) */
  ::placeholder {
    color: red;
  }
  body :is() {
    color: green;
  }
  @supports (color: blue) {
     {
      color: blue;
    }
  }
  
  /* New output (with --supported:nesting=false) */
  ::placeholder {
    color: red;
  }
  body :is() {
    color: green;
  }
  @supports (color: blue) {
    ::placeholder {
      color: blue;
    }
  }

Does any of this look wrong? Please let us know.

See the full diff on Github. The new version differs by 64 commits:

• publish 0.27.2 to npm
• additional tests for `switch` with `break`
• update release notes
• fix #4357: -webkit- prefix for mask shorthand (#4358)
• compat table: update `@types/node`
• compat table: fix a type error with the new types
• fix `make compat-table` to install dependencies
• release notes for #4361
• fix: allow subpath imports that start with `#/` (#4361)
• minify some switch statements to if-else statement
• fix #4176: improve switch statement partial-eval
• introduce more helper methods
• fix some extremely subtle switch minification bugs
• introduce a helper method
• fix #4359: prune empty `case` before a `default`
• fix #4323: forbid `using` inside `switch` clauses
• close #4362, close #4363: update to go 1.25.5
• publish 0.27.1 to npm
• fix #4354: improve IIFE inlining for expressions
• minify: move unused expr simplification later
• fix #4353: remove empty `try`/`finally` clauses
• fix #4348: bundler bug with `var` inside `if`
• fix #4351: label + `try` + `for` minifier bug
• fix: deno release url wrong comment (#4326)
• calling `Symbol.for` with a primitive never throws
• update `decorator-tests.js` snapshot
• calling `Symbol` with a primitive will never throw
• publish 0.27.0 to npm
• fix #4286: use `Uint8Array.fromBase64` if present (#4295)
• update go 1.25.3 => 1.25.4
• update go 1.23.12 => 1.25.3 (#4318)
• use a patched go compiler for release builds
• delete temporary `release.yml` workflow
• add a temporary `release.yml` workflow
• fix `publish.yml`
• publish 0.26.0 to npm
• enable trusted publishing (#4319)
• some deno-related fixes
• add a dummy `publish.yml`
• publish 0.25.12 to npm
• update release notes
• minify: remove css rules containing empty `:is()`
• add some additional known static methods
• automatically mark "RegExp.escape()" calls as pure
• simplify some call expression checks
• add some additional known static methods
• fix #4310: add `Iterator` and other known globals
• fix: escape dev server breadcrumb hrefs properly (#4316)
• fix #4315: `@media` deduplication bug edge case
• update release notes
• feat: add CSS `@view-transition` (#4313)
• publish 0.25.11 to npm
• css: also parse media queries in `@import` rules
• css: some adjustments to `@import` parsing
• fix #3748, fix #4293: lower css media range syntax
• css: parse and print media queries
• run `make update-compat-table`
• fix #4292: support `with { type: bytes }`
• publish 0.25.10 to npm
• refactor: use strings.Builder (#4290)
• run `make update-compat-table`
• fix #4287: marked the wrong issue as fixed
• fix #4286: minifier panic due to identity function
• fix #4265: `@supports` nested inside `::pseudo`

0.27.2

• Allow import path specifiers starting with #/ (#4361)

  Previously the specification for package.json disallowed import path specifiers starting with #/, but this restriction has recently been relaxed and support for it is being added across the JavaScript ecosystem. One use case is using it for a wildcard pattern such as mapping #/* to ./src/* (previously you had to use another character such as #_* instead, which was more confusing). There is some more context in nodejs/node#49182.

  This change was contributed by @hybrist.

• Automatically add the -webkit-mask prefix (#4357, #4358)

  This release automatically adds the -webkit- vendor prefix for the mask CSS shorthand property:

  /* Original code */
  main {
    mask: url(x.png) center/5rem no-repeat
  }
  
  /* Old output (with --target=chrome110) */
  main {
    mask: url(x.png) center/5rem no-repeat;
  }
  
  /* New output (with --target=chrome110) */
  main {
    -webkit-mask: url(x.png) center/5rem no-repeat;
    mask: url(x.png) center/5rem no-repeat;
  }

  This change was contributed by @BPJEnnova.

• Additional minification of switch statements (#4176, #4359)

  This release contains additional minification patterns for reducing switch statements. Here is an example:

  // Original code
  switch (x) {
    case 0:
      foo()
      break
    case 1:
    default:
      bar()
  }
  
  // Old output (with --minify)
  switch(x){case 0:foo();break;case 1:default:bar()}
  
  // New output (with --minify)
  x===0?foo():bar();

• Forbid using declarations inside switch clauses (#4323)

  This is a rare change to remove something that was previously possible. The Explicit Resource Management proposal introduced using declarations. These were previously allowed inside case and default clauses in switch statements. This had well-defined semantics and was already widely implemented (by V8, SpiderMonkey, TypeScript, esbuild, and others). However, it was considered to be too confusing because of how scope works in switch statements, so it has been removed from the specification. This edge case will now be a syntax error. See tc39/proposal-explicit-resource-management#215 and rbuckton/ecma262#14 for details.

  Here is an example of code that is no longer allowed:

  switch (mode) {
    case 'read':
      using readLock = db.read()
      return readAll(readLock)
  
    case 'write':
      using writeLock = db.write()
      return writeAll(writeLock)
  }

  That code will now have to be modified to look like this instead (note the additional { and } block statements around each case body):

  switch (mode) {
    case 'read': {
      using readLock = db.read()
      return readAll(readLock)
    }
    case 'write': {
      using writeLock = db.write()
      return writeAll(writeLock)
    }
  }

  This is not being released in one of esbuild's breaking change releases since this feature hasn't been finalized yet, and esbuild always tracks the current state of the specification (so esbuild's previous behavior was arguably incorrect).

0.27.1

• Fix bundler bug with var nested inside if (#4348)

  This release fixes a bug with the bundler that happens when importing an ES module using require (which causes it to be wrapped) and there's a top-level var inside an if statement without being wrapped in a { ... } block (and a few other conditions). The bundling transform needed to hoist these var declarations outside of the lazy ES module wrapper for correctness. See the issue for details.

• Fix minifier bug with for inside try inside label (#4351)

  This fixes an old regression from version v0.21.4. Some code was introduced to move the label inside the try statement to address a problem with transforming labeled for await loops to avoid the await (the transformation involves converting the for await loop into a for loop and wrapping it in a try statement). However, it introduces problems for cross-compiled JVM code that uses all three of these features heavily. This release restricts this transform to only apply to for loops that esbuild itself generates internally as part of the for await transform. Here is an example of some affected code:

  // Original code
  d: {
    e: {
      try {
        while (1) { break d }
      } catch { break e; }
    }
  }
  
  // Old output (with --minify)
  a:try{e:for(;;)break a}catch{break e}
  
  // New output (with --minify)
  a:e:try{for(;;)break a}catch{break e}

• Inline IIFEs containing a single expression (#4354)

  Previously inlining of IIFEs (immediately-invoked function expressions) only worked if the body contained a single return statement. Now it should also work if the body contains a single expression statement instead:

  // Original code
  const foo = () => {
    const cb = () => {
      console.log(x())
    }
    return cb()
  }
  
  // Old output (with --minify)
  const foo=()=>(()=>{console.log(x())})();
  
  // New output (with --minify)
  const foo=()=>{console.log(x())};

• The minifier now strips empty finally clauses (#4353)

  This improvement means that finally clauses containing dead code can potentially cause the associated try statement to be removed from the output entirely in minified builds:

  // Original code
  function foo(callback) {
    if (DEBUG) stack.push(callback.name);
    try {
      callback();
    } finally {
      if (DEBUG) stack.pop();
    }
  }
  
  // Old output (with --minify --define:DEBUG=false)
  function foo(a){try{a()}finally{}}
  
  // New output (with --minify --define:DEBUG=false)
  function foo(a){a()}

• Allow tree-shaking of the Symbol constructor

  With this release, calling Symbol is now considered to be side-effect free when the argument is known to be a primitive value. This means esbuild can now tree-shake module-level symbol variables:

  // Original code
  const a = Symbol('foo')
  const b = Symbol(bar)
  
  // Old output (with --tree-shaking=true)
  const a = Symbol("foo");
  const b = Symbol(bar);
  
  // New output (with --tree-shaking=true)
  const b = Symbol(bar);

0.27.0

This release deliberately contains backwards-incompatible changes. To avoid automatically picking up releases like this, you should either be pinning the exact version of esbuild in your package.json file (recommended) or be using a version range syntax that only accepts patch upgrades such as ^0.26.0 or ~0.26.0. See npm's documentation about semver for more information.

• Use Uint8Array.fromBase64 if available (#4286)

  With this release, esbuild's binary loader will now use the new Uint8Array.fromBase64 function unless it's unavailable in the configured target environment. If it's unavailable, esbuild's previous code for this will be used as a fallback. Note that this means you may now need to specify target when using this feature with Node (for example --target=node22) unless you're using Node v25+.

• Update the Go compiler from v1.23.12 to v1.25.4 (#4208, #4311)

  This raises the operating system requirements for running esbuild:

  • Linux: now requires a kernel version of 3.2 or later
  • macOS: now requires macOS 12 (Monterey) or later

0.26.0

• Enable trusted publishing (#4281)

  GitHub and npm are recommending that maintainers for packages such as esbuild switch to trusted publishing. With this release, a VM on GitHub will now build and publish all of esbuild's packages to npm instead of me. In theory.

  Unfortunately there isn't really a way to test that this works other than to do it live. So this release is that live test. Hopefully this release is uneventful and is exactly the same as the previous one (well, except for the green provenance attestation checkmark on npm that happens with trusted publishing).

0.25.12

• Fix a minification regression with CSS media queries (#4315)

  The previous release introduced support for parsing media queries which unintentionally introduced a regression with the removal of duplicate media rules during minification. Specifically the grammar for @media <media-type> and <media-condition-without-or> { ... } was missing an equality check for the <media-condition-without-or> part, so rules with different suffix clauses in this position would incorrectly compare equal and be deduplicated. This release fixes the regression.

• Update the list of known JavaScript globals (#4310)

  This release updates esbuild's internal list of known JavaScript globals. These are globals that are known to not have side-effects when the property is accessed. For example, accessing the global Array property is considered to be side-effect free but accessing the global scrollY property can trigger a layout, which is a side-effect. This is used by esbuild's tree-shaking to safely remove unused code that is known to be side-effect free. This update adds the following global properties:

  From ES2017:

  • Atomics
  • SharedArrayBuffer

  From ES2020:

  • BigInt64Array
  • BigUint64Array

  From ES2021:

  • FinalizationRegistry
  • WeakRef

  From ES2025:

  • Float16Array
  • Iterator

  Note that this does not indicate that constructing any of these objects is side-effect free, just that accessing the identifier is side-effect free. For example, this now allows esbuild to tree-shake classes that extend from Iterator:

  // This can now be tree-shaken by esbuild:
  class ExampleIterator extends Iterator {}

• Add support for the new @view-transition CSS rule (#4313)

  With this release, esbuild now has improved support for pretty-printing and minifying the new @view-transition rule (which esbuild was previously unaware of):

  /* Original code */
  @view-transition {
    navigation: auto;
    types: check;
  }
  
  /* Old output */
  @view-transition { navigation: auto; types: check; }
  
  /* New output */
  @view-transition {
    navigation: auto;
    types: check;
  }

  The new view transition feature provides a mechanism for creating animated transitions between documents in a multi-page app. You can read more about view transition rules here.

  This change was contributed by @yisibl.

• Trim CSS rules that will never match

  The CSS minifier will now remove rules whose selectors contain :is() and :where() as those selectors will never match. These selectors can currently be automatically generated by esbuild when you give esbuild nonsensical input such as the following:

  /* Original code */
  div:before {
    color: green;
    &.foo {
      color: red;
    }
  }
  
  /* Old output (with --supported:nesting=false --minify) */
  div:before{color:green}:is().foo{color:red}
  
  /* New output (with --supported:nesting=false --minify) */
  div:before{color:green}

  This input is nonsensical because CSS nesting is (unfortunately) not supported inside of pseudo-elements such as :before. Currently esbuild generates a rule containing :is() in this case when you tell esbuild to transform nested CSS into non-nested CSS. I think it's reasonable to do that as it sort of helps explain what's going on (or at least indicates that something is wrong in the output). It shouldn't be present in minified code, however, so this release now strips it out.

0.25.11

• Add support for with { type: 'bytes' } imports (#4292)

  The import bytes proposal has reached stage 2.7 in the TC39 process, which means that although it isn't quite recommended for implementation, it's generally approved and ready for validation. Furthermore it has already been implemented by Deno and Webpack. So with this release, esbuild will also add support for this. It behaves exactly the same as esbuild's existing binary loader. Here's an example:

  import data from './image.png' with { type: 'bytes' }
  const view = new DataView(data.buffer, 0, 24)
  const width = view.getInt32(16)
  const height = view.getInt32(20)
  console.log('size:', width + '\xD7' + height)

• Lower CSS media query range syntax (#3748, #4293)

  With this release, esbuild will now transform CSS media query range syntax into equivalent syntax using min-/max- prefixes for older browsers. For example, the following CSS:

  @media (640px <= width <= 960px) {
    main {
      display: flex;
    }
  }

  will be transformed like this with a target such as --target=chrome100 (or more specifically with --supported:media-range=false if desired):

  @media (min-width: 640px) and (max-width: 960px) {
    main {
      display: flex;
    }
  }

0.25.10

• Fix a panic in a minification edge case (#4287)

  This release fixes a panic due to a null pointer that could happen when esbuild inlines a doubly-nested identity function and the final result is empty. It was fixed by emitting the value undefined in this case, which avoids the panic. This case must be rare since it hasn't come up until now. Here is an example of code that previously triggered the panic (which only happened when minifying):

  function identity(x) { return x }
  identity({ y: identity(123) })

• Fix @supports nested inside pseudo-element (#4265)

  When transforming nested CSS to non-nested CSS, esbuild is supposed to filter out pseudo-elements such as ::placeholder for correctness. The CSS nesting specification says the following:

  The nesting selector cannot represent pseudo-elements (identical to the behavior of the ':is()' pseudo-class). We’d like to relax this restriction, but need to do so simultaneously for both ':is()' and '&', since they’re intentionally built on the same underlying mechanisms.

  However, it seems like this behavior is different for nested at-rules such as @supports, which do work with pseudo-elements. So this release modifies esbuild's behavior to now take that into account:

  /* Original code */
  ::placeholder {
    color: red;
    body & { color: green }
    @supports (color: blue) { color: blue }
  }
  
  /* Old output (with --supported:nesting=false) */
  ::placeholder {
    color: red;
  }
  body :is() {
    color: green;
  }
  @supports (color: blue) {
     {
      color: blue;
    }
  }
  
  /* New output (with --supported:nesting=false) */
  ::placeholder {
    color: red;
  }
  body :is() {
    color: green;
  }
  @supports (color: blue) {
    ::placeholder {
      color: blue;
    }
  }

Does any of this look wrong? Please let us know.

See the full diff on Github. The new version differs by 64 commits:

• publish 0.27.2 to npm
• additional tests for `switch` with `break`
• update release notes
• fix #4357: -webkit- prefix for mask shorthand (#4358)
• compat table: update `@types/node`
• compat table: fix a type error with the new types
• fix `make compat-table` to install dependencies
• release notes for #4361
• fix: allow subpath imports that start with `#/` (#4361)
• minify some switch statements to if-else statement
• fix #4176: improve switch statement partial-eval
• introduce more helper methods
• fix some extremely subtle switch minification bugs
• introduce a helper method
• fix #4359: prune empty `case` before a `default`
• fix #4323: forbid `using` inside `switch` clauses
• close #4362, close #4363: update to go 1.25.5
• publish 0.27.1 to npm
• fix #4354: improve IIFE inlining for expressions
• minify: move unused expr simplification later
• fix #4353: remove empty `try`/`finally` clauses
• fix #4348: bundler bug with `var` inside `if`
• fix #4351: label + `try` + `for` minifier bug
• fix: deno release url wrong comment (#4326)
• calling `Symbol.for` with a primitive never throws
• update `decorator-tests.js` snapshot
• calling `Symbol` with a primitive will never throw
• publish 0.27.0 to npm
• fix #4286: use `Uint8Array.fromBase64` if present (#4295)
• update go 1.25.3 => 1.25.4
• update go 1.23.12 => 1.25.3 (#4318)
• use a patched go compiler for release builds
• delete temporary `release.yml` workflow
• add a temporary `release.yml` workflow
• fix `publish.yml`
• publish 0.26.0 to npm
• enable trusted publishing (#4319)
• some deno-related fixes
• add a dummy `publish.yml`
• publish 0.25.12 to npm
• update release notes
• minify: remove css rules containing empty `:is()`
• add some additional known static methods
• automatically mark "RegExp.escape()" calls as pure
• simplify some call expression checks
• add some additional known static methods
• fix #4310: add `Iterator` and other known globals
• fix: escape dev server breadcrumb hrefs properly (#4316)
• fix #4315: `@media` deduplication bug edge case
• update release notes
• feat: add CSS `@view-transition` (#4313)
• publish 0.25.11 to npm
• css: also parse media queries in `@import` rules
• css: some adjustments to `@import` parsing
• fix #3748, fix #4293: lower css media range syntax
• css: parse and print media queries
• run `make update-compat-table`
• fix #4292: support `with { type: bytes }`
• publish 0.25.10 to npm
• refactor: use strings.Builder (#4290)
• run `make update-compat-table`
• fix #4287: marked the wrong issue as fixed
• fix #4286: minifier panic due to identity function
• fix #4265: `@supports` nested inside `::pseudo`

0.27.2

• Allow import path specifiers starting with #/ (#4361)

  Previously the specification for package.json disallowed import path specifiers starting with #/, but this restriction has recently been relaxed and support for it is being added across the JavaScript ecosystem. One use case is using it for a wildcard pattern such as mapping #/* to ./src/* (previously you had to use another character such as #_* instead, which was more confusing). There is some more context in nodejs/node#49182.

  This change was contributed by @hybrist.

• Automatically add the -webkit-mask prefix (#4357, #4358)

  This release automatically adds the -webkit- vendor prefix for the mask CSS shorthand property:

  /* Original code */
  main {
    mask: url(x.png) center/5rem no-repeat
  }
  
  /* Old output (with --target=chrome110) */
  main {
    mask: url(x.png) center/5rem no-repeat;
  }
  
  /* New output (with --target=chrome110) */
  main {
    -webkit-mask: url(x.png) center/5rem no-repeat;
    mask: url(x.png) center/5rem no-repeat;
  }

  This change was contributed by @BPJEnnova.

• Additional minification of switch statements (#4176, #4359)

  This release contains additional minification patterns for reducing switch statements. Here is an example:

  // Original code
  switch (x) {
    case 0:
      foo()
      break
    case 1:
    default:
      bar()
  }
  
  // Old output (with --minify)
  switch(x){case 0:foo();break;case 1:default:bar()}
  
  // New output (with --minify)
  x===0?foo():bar();

• Forbid using declarations inside switch clauses (#4323)

  This is a rare change to remove something that was previously possible. The Explicit Resource Management proposal introduced using declarations. These were previously allowed inside case and default clauses in switch statements. This had well-defined semantics and was already widely implemented (by V8, SpiderMonkey, TypeScript, esbuild, and others). However, it was considered to be too confusing because of how scope works in switch statements, so it has been removed from the specification. This edge case will now be a syntax error. See tc39/proposal-explicit-resource-management#215 and rbuckton/ecma262#14 for details.

  Here is an example of code that is no longer allowed:

  switch (mode) {
    case 'read':
      using readLock = db.read()
      return readAll(readLock)
  
    case 'write':
      using writeLock = db.write()
      return writeAll(writeLock)
  }

  That code will now have to be modified to look like this instead (note the additional { and } block statements around each case body):

  switch (mode) {
    case 'read': {
      using readLock = db.read()
      return readAll(readLock)
    }
    case 'write': {
      using writeLock = db.write()
      return writeAll(writeLock)
    }
  }

  This is not being released in one of esbuild's breaking change releases since this feature hasn't been finalized yet, and esbuild always tracks the current state of the specification (so esbuild's previous behavior was arguably incorrect).

0.27.1

• Fix bundler bug with var nested inside if (#4348)

  This release fixes a bug with the bundler that happens when importing an ES module using require (which causes it to be wrapped) and there's a top-level var inside an if statement without being wrapped in a { ... } block (and a few other conditions). The bundling transform needed to hoist these var declarations outside of the lazy ES module wrapper for correctness. See the issue for details.

• Fix minifier bug with for inside try inside label (#4351)

  This fixes an old regression from version v0.21.4. Some code was introduced to move the label inside the try statement to address a problem with transforming labeled for await loops to avoid the await (the transformation involves converting the for await loop into a for loop and wrapping it in a try statement). However, it introduces problems for cross-compiled JVM code that uses all three of these features heavily. This release restricts this transform to only apply to for loops that esbuild itself generates internally as part of the for await transform. Here is an example of some affected code:

  // Original code
  d: {
    e: {
      try {
        while (1) { break d }
      } catch { break e; }
    }
  }
  
  // Old output (with --minify)
  a:try{e:for(;;)break a}catch{break e}
  
  // New output (with --minify)
  a:e:try{for(;;)break a}catch{break e}

• Inline IIFEs containing a single expression (#4354)

  Previously inlining of IIFEs (immediately-invoked function expressions) only worked if the body contained a single return statement. Now it should also work if the body contains a single expression statement instead:

  // Original code
  const foo = () => {
    const cb = () => {
      console.log(x())
    }
    return cb()
  }
  
  // Old output (with --minify)
  const foo=()=>(()=>{console.log(x())})();
  
  // New output (with --minify)
  const foo=()=>{console.log(x())};

• The minifier now strips empty finally clauses (#4353)

  This improvement means that finally clauses containing dead code can potentially cause the associated try statement to be removed from the output entirely in minified builds:

  // Original code
  function foo(callback) {
    if (DEBUG) stack.push(callback.name);
    try {
      callback();
    } finally {
      if (DEBUG) stack.pop();
    }
  }
  
  // Old output (with --minify --define:DEBUG=false)
  function foo(a){try{a()}finally{}}
  
  // New output (with --minify --define:DEBUG=false)
  function foo(a){a()}

• Allow tree-shaking of the Symbol constructor

  With this release, calling Symbol is now considered to be side-effect free when the argument is known to be a primitive value. This means esbuild can now tree-shake module-level symbol variables:

  // Original code
  const a = Symbol('foo')
  const b = Symbol(bar)
  
  // Old output (with --tree-shaking=true)
  const a = Symbol("foo");
  const b = Symbol(bar);
  
  // New output (with --tree-shaking=true)
  const b = Symbol(bar);

0.27.0

This release deliberately contains backwards-incompatible changes. To avoid automatically picking up releases like this, you should either be pinning the exact version of esbuild in your package.json file (recommended) or be using a version range syntax that only accepts patch upgrades such as ^0.26.0 or ~0.26.0. See npm's documentation about semver for more information.

• Use Uint8Array.fromBase64 if available (#4286)

  With this release, esbuild's binary loader will now use the new Uint8Array.fromBase64 function unless it's unavailable in the configured target environment. If it's unavailable, esbuild's previous code for this will be used as a fallback. Note that this means you may now need to specify target when using this feature with Node (for example --target=node22) unless you're using Node v25+.

• Update the Go compiler from v1.23.12 to v1.25.4 (#4208, #4311)

  This raises the operating system requirements for running esbuild:

  • Linux: now requires a kernel version of 3.2 or later
  • macOS: now requires macOS 12 (Monterey) or later

0.26.0

• Enable trusted publishing (#4281)

  GitHub and npm are recommending that maintainers for packages such as esbuild switch to trusted publishing. With this release, a VM on GitHub will now build and publish all of esbuild's packages to npm instead of me. In theory.

  Unfortunately there isn't really a way to test that this works other than to do it live. So this release is that live test. Hopefully this release is uneventful and is exactly the same as the previous one (well, except for the green provenance attestation checkmark on npm that happens with trusted publishing).

0.25.12

• Fix a minification regression with CSS media queries (#4315)

  The previous release introduced support for parsing media queries which unintentionally introduced a regression with the removal of duplicate media rules during minification. Specifically the grammar for @media <media-type> and <media-condition-without-or> { ... } was missing an equality check for the <media-condition-without-or> part, so rules with different suffix clauses in this position would incorrectly compare equal and be deduplicated. This release fixes the regression.

• Update the list of known JavaScript globals (#4310)

  This release updates esbuild's internal list of known JavaScript globals. These are globals that are known to not have side-effects when the property is accessed. For example, accessing the global Array property is considered to be side-effect free but accessing the global scrollY property can trigger a layout, which is a side-effect. This is used by esbuild's tree-shaking to safely remove unused code that is known to be side-effect free. This update adds the following global properties:

  From ES2017:

  • Atomics
  • SharedArrayBuffer

  From ES2020:

  • BigInt64Array
  • BigUint64Array

  From ES2021:

  • FinalizationRegistry
  • WeakRef

  From ES2025:

  • Float16Array
  • Iterator

  Note that this does not indicate that constructing any of these objects is side-effect free, just that accessing the identifier is side-effect free. For example, this now allows esbuild to tree-shake classes that extend from Iterator:

  // This can now be tree-shaken by esbuild:
  class ExampleIterator extends Iterator {}

• Add support for the new @view-transition CSS rule (#4313)

  With this release, esbuild now has improved support for pretty-printing and minifying the new @view-transition rule (which esbuild was previously unaware of):

  /* Original code */
  @view-transition {
    navigation: auto;
    types: check;
  }
  
  /* Old output */
  @view-transition { navigation: auto; types: check; }
  
  /* New output */
  @view-transition {
    navigation: auto;
    types: check;
  }

  The new view transition feature provides a mechanism for creating animated transitions between documents in a multi-page app. You can read more about view transition rules here.

  This change was contributed by @yisibl.

• Trim CSS rules that will never match

  The CSS minifier will now remove rules whose selectors contain :is() and :where() as those selectors will never match. These selectors can currently be automatically generated by esbuild when you give esbuild nonsensical input such as the following:

  /* Original code */
  div:before {
    color: green;
    &.foo {
      color: red;
    }
  }
  
  /* Old output (with --supported:nesting=false --minify) */
  div:before{color:green}:is().foo{color:red}
  
  /* New output (with --supported:nesting=false --minify) */
  div:before{color:green}

  This input is nonsensical because CSS nesting is (unfortunately) not supported inside of pseudo-elements such as :before. Currently esbuild generates a rule containing :is() in this case when you tell esbuild to transform nested CSS into non-nested CSS. I think it's reasonable to do that as it sort of helps explain what's going on (or at least indicates that something is wrong in the output). It shouldn't be present in minified code, however, so this release now strips it out.

0.25.11

• Add support for with { type: 'bytes' } imports (#4292)

  The import bytes proposal has reached stage 2.7 in the TC39 process, which means that although it isn't quite recommended for implementation, it's generally approved and ready for validation. Furthermore it has already been implemented by Deno and Webpack. So with this release, esbuild will also add support for this. It behaves exactly the same as esbuild's existing binary loader. Here's an example:

  import data from './image.png' with { type: 'bytes' }
  const view = new DataView(data.buffer, 0, 24)
  const width = view.getInt32(16)
  const height = view.getInt32(20)
  console.log('size:', width + '\xD7' + height)

• Lower CSS media query range syntax (#3748, #4293)

  With this release, esbuild will now transform CSS media query range syntax into equivalent syntax using min-/max- prefixes for older browsers. For example, the following CSS:

  @media (640px <= width <= 960px) {
    main {
      display: flex;
    }
  }

  will be transformed like this with a target such as --target=chrome100 (or more specifically with --supported:media-range=false if desired):

  @media (min-width: 640px) and (max-width: 960px) {
    main {
      display: flex;
    }
  }

0.25.10

• Fix a panic in a minification edge case (#4287)

  This release fixes a panic due to a null pointer that could happen when esbuild inlines a doubly-nested identity function and the final result is empty. It was fixed by emitting the value undefined in this case, which avoids the panic. This case must be rare since it hasn't come up until now. Here is an example of code that previously triggered the panic (which only happened when minifying):

  function identity(x) { return x }
  identity({ y: identity(123) })

• Fix @supports nested inside pseudo-element (#4265)

  When transforming nested CSS to non-nested CSS, esbuild is supposed to filter out pseudo-elements such as ::placeholder for correctness. The CSS nesting specification says the following:

  The nesting selector cannot represent pseudo-elements (identical to the behavior of the ':is()' pseudo-class). We’d like to relax this restriction, but need to do so simultaneously for both ':is()' and '&', since they’re intentionally built on the same underlying mechanisms.

  However, it seems like this behavior is different for nested at-rules such as @supports, which do work with pseudo-elements. So this release modifies esbuild's behavior to now take that into account:

  /* Original code */
  ::placeholder {
    color: red;
    body & { color: green }
    @supports (color: blue) { color: blue }
  }
  
  /* Old output (with --supported:nesting=false) */
  ::placeholder {
    color: red;
  }
  body :is() {
    color: green;
  }
  @supports (color: blue) {
     {
      color: blue;
    }
  }
  
  /* New output (with --supported:nesting=false) */
  ::placeholder {
    color: red;
  }
  body :is() {
    color: green;
  }
  @supports (color: blue) {
    ::placeholder {
      color: blue;
    }
  }

Does any of this look wrong? Please let us know.

See the full diff on Github. The new version differs by 64 commits:

• publish 0.27.2 to npm
• additional tests for `switch` with `break`
• update release notes
• fix #4357: -webkit- prefix for mask shorthand (#4358)
• compat table: update `@types/node`
• compat table: fix a type error with the new types
• fix `make compat-table` to install dependencies
• release notes for #4361
• fix: allow subpath imports that start with `#/` (#4361)
• minify some switch statements to if-else statement
• fix #4176: improve switch statement partial-eval
• introduce more helper methods
• fix some extremely subtle switch minification bugs
• introduce a helper method
• fix #4359: prune empty `case` before a `default`
• fix #4323: forbid `using` inside `switch` clauses
• close #4362, close #4363: update to go 1.25.5
• publish 0.27.1 to npm
• fix #4354: improve IIFE inlining for expressions
• minify: move unused expr simplification later
• fix #4353: remove empty `try`/`finally` clauses
• fix #4348: bundler bug with `var` inside `if`
• fix #4351: label + `try` + `for` minifier bug
• fix: deno release url wrong comment (#4326)
• calling `Symbol.for` with a primitive never throws
• update `decorator-tests.js` snapshot
• calling `Symbol` with a primitive will never throw
• publish 0.27.0 to npm
• fix #4286: use `Uint8Array.fromBase64` if present (#4295)
• update go 1.25.3 => 1.25.4
• update go 1.23.12 => 1.25.3 (#4318)
• use a patched go compiler for release builds
• delete temporary `release.yml` workflow
• add a temporary `release.yml` workflow
• fix `publish.yml`
• publish 0.26.0 to npm
• enable trusted publishing (#4319)
• some deno-related fixes
• add a dummy `publish.yml`
• publish 0.25.12 to npm
• update release notes
• minify: remove css rules containing empty `:is()`
• add some additional known static methods
• automatically mark "RegExp.escape()" calls as pure
• simplify some call expression checks
• add some additional known static methods
• fix #4310: add `Iterator` and other known globals
• fix: escape dev server breadcrumb hrefs properly (#4316)
• fix #4315: `@media` deduplication bug edge case
• update release notes
• feat: add CSS `@view-transition` (#4313)
• publish 0.25.11 to npm
• css: also parse media queries in `@import` rules
• css: some adjustments to `@import` parsing
• fix #3748, fix #4293: lower css media range syntax
• css: parse and print media queries
• run `make update-compat-table`
• fix #4292: support `with { type: bytes }`
• publish 0.25.10 to npm
• refactor: use strings.Builder (#4290)
• run `make update-compat-table`
• fix #4287: marked the wrong issue as fixed
• fix #4286: minifier panic due to identity function
• fix #4265: `@supports` nested inside `::pseudo`

0.27.2

• Allow import path specifiers starting with #/ (#4361)

  Previously the specification for package.json disallowed import path specifiers starting with #/, but this restriction has recently been relaxed and support for it is being added across the JavaScript ecosystem. One use case is using it for a wildcard pattern such as mapping #/* to ./src/* (previously you had to use another character such as #_* instead, which was more confusing). There is some more context in nodejs/node#49182.

  This change was contributed by @hybrist.

• Automatically add the -webkit-mask prefix (#4357, #4358)

  This release automatically adds the -webkit- vendor prefix for the mask CSS shorthand property:

  /* Original code */
  main {
    mask: url(x.png) center/5rem no-repeat
  }
  
  /* Old output (with --target=chrome110) */
  main {
    mask: url(x.png) center/5rem no-repeat;
  }
  
  /* New output (with --target=chrome110) */
  main {
    -webkit-mask: url(x.png) center/5rem no-repeat;
    mask: url(x.png) center/5rem no-repeat;
  }

  This change was contributed by @BPJEnnova.

• Additional minification of switch statements (#4176, #4359)

  This release contains additional minification patterns for reducing switch statements. Here is an example:

  // Original code
  switch (x) {
    case 0:
      foo()
      break
    case 1:
    default:
      bar()
  }
  
  // Old output (with --minify)
  switch(x){case 0:foo();break;case 1:default:bar()}
  
  // New output (with --minify)
  x===0?foo():bar();

• Forbid using declarations inside switch clauses (#4323)

  This is a rare change to remove something that was previously possible. The Explicit Resource Management proposal introduced using declarations. These were previously allowed inside case and default clauses in switch statements. This had well-defined semantics and was already widely implemented (by V8, SpiderMonkey, TypeScript, esbuild, and others). However, it was considered to be too confusing because of how scope works in switch statements, so it has been removed from the specification. This edge case will now be a syntax error. See tc39/proposal-explicit-resource-management#215 and rbuckton/ecma262#14 for details.

  Here is an example of code that is no longer allowed:

  switch (mode) {
    case 'read':
      using readLock = db.read()
      return readAll(readLock)
  
    case 'write':
      using writeLock = db.write()
      return writeAll(writeLock)
  }

  That code will now have to be modified to look like this instead (note the additional { and } block statements around each case body):

  switch (mode) {
    case 'read': {
      using readLock = db.read()
      return readAll(readLock)
    }
    case 'write': {
      using writeLock = db.write()
      return writeAll(writeLock)
    }
  }

  This is not being released in one of esbuild's breaking change releases since this feature hasn't been finalized yet, and esbuild always tracks the current state of the specification (so esbuild's previous behavior was arguably incorrect).

0.27.1

• Fix bundler bug with var nested inside if (#4348)

  This release fixes a bug with the bundler that happens when importing an ES module using require (which causes it to be wrapped) and there's a top-level var inside an if statement without being wrapped in a { ... } block (and a few other conditions). The bundling transform needed to hoist these var declarations outside of the lazy ES module wrapper for correctness. See the issue for details.

• Fix minifier bug with for inside try inside label (#4351)

  This fixes an old regression from version v0.21.4. Some code was introduced to move the label inside the try statement to address a problem with transforming labeled for await loops to avoid the await (the transformation involves converting the for await loop into a for loop and wrapping it in a try statement). However, it introduces problems for cross-compiled JVM code that uses all three of these features heavily. This release restricts this transform to only apply to for loops that esbuild itself generates internally as part of the for await transform. Here is an example of some affected code:

  // Original code
  d: {
    e: {
      try {
        while (1) { break d }
      } catch { break e; }
    }
  }
  
  // Old output (with --minify)
  a:try{e:for(;;)break a}catch{break e}
  
  // New output (with --minify)
  a:e:try{for(;;)break a}catch{break e}

• Inline IIFEs containing a single expression (#4354)

  Previously inlining of IIFEs (immediately-invoked function expressions) only worked if the body contained a single return statement. Now it should also work if the body contains a single expression statement instead:

  // Original code
  const foo = () => {
    const cb = () => {
      console.log(x())
    }
    return cb()
  }
  
  // Old output (with --minify)
  const foo=()=>(()=>{console.log(x())})();
  
  // New output (with --minify)
  const foo=()=>{console.log(x())};

• The minifier now strips empty finally clauses (#4353)

  This improvement means that finally clauses containing dead code can potentially cause the associated try statement to be removed from the output entirely in minified builds:

  // Original code
  function foo(callback) {
    if (DEBUG) stack.push(callback.name);
    try {
      callback();
    } finally {
      if (DEBUG) stack.pop();
    }
  }
  
  // Old output (with --minify --define:DEBUG=false)
  function foo(a){try{a()}finally{}}
  
  // New output (with --minify --define:DEBUG=false)
  function foo(a){a()}

• Allow tree-shaking of the Symbol constructor

  With this release, calling Symbol is now considered to be side-effect free when the argument is known to be a primitive value. This means esbuild can now tree-shake module-level symbol variables:

  // Original code
  const a = Symbol('foo')
  const b = Symbol(bar)
  
  // Old output (with --tree-shaking=true)
  const a = Symbol("foo");
  const b = Symbol(bar);
  
  // New output (with --tree-shaking=true)
  const b = Symbol(bar);

0.27.0

This release deliberately contains backwards-incompatible changes. To avoid automatically picking up releases like this, you should either be pinning the exact version of esbuild in your package.json file (recommended) or be using a version range syntax that only accepts patch upgrades such as ^0.26.0 or ~0.26.0. See npm's documentation about semver for more information.

• Use Uint8Array.fromBase64 if available (#4286)

  With this release, esbuild's binary loader will now use the new Uint8Array.fromBase64 function unless it's unavailable in the configured target environment. If it's unavailable, esbuild's previous code for this will be used as a fallback. Note that this means you may now need to specify target when using this feature with Node (for example --target=node22) unless you're using Node v25+.

• Update the Go compiler from v1.23.12 to v1.25.4 (#4208, #4311)

  This raises the operating system requirements for running esbuild:

  • Linux: now requires a kernel version of 3.2 or later
  • macOS: now requires macOS 12 (Monterey) or later

0.26.0

• Enable trusted publishing (#4281)

  GitHub and npm are recommending that maintainers for packages such as esbuild switch to trusted publishing. With this release, a VM on GitHub will now build and publish all of esbuild's packages to npm instead of me. In theory.

  Unfortunately there isn't really a way to test that this works other than to do it live. So this release is that live test. Hopefully this release is uneventful and is exactly the same as the previous one (well, except for the green provenance attestation checkmark on npm that happens with trusted publishing).

0.25.12

• Fix a minification regression with CSS media queries (#4315)

  The previous release introduced support for parsing media queries which unintentionally introduced a regression with the removal of duplicate media rules during minification. Specifically the grammar for @media <media-type> and <media-condition-without-or> { ... } was missing an equality check for the <media-condition-without-or> part, so rules with different suffix clauses in this position would incorrectly compare equal and be deduplicated. This release fixes the regression.

• Update the list of known JavaScript globals (#4310)

  This release updates esbuild's internal list of known JavaScript globals. These are globals that are known to not have side-effects when the property is accessed. For example, accessing the global Array property is considered to be side-effect free but accessing the global scrollY property can trigger a layout, which is a side-effect. This is used by esbuild's tree-shaking to safely remove unused code that is known to be side-effect free. This update adds the following global properties:

  From ES2017:

  • Atomics
  • SharedArrayBuffer

  From ES2020:

  • BigInt64Array
  • BigUint64Array

  From ES2021:

  • FinalizationRegistry
  • WeakRef

  From ES2025:

  • Float16Array
  • Iterator

  Note that this does not indicate that constructing any of these objects is side-effect free, just that accessing the identifier is side-effect free. For example, this now allows esbuild to tree-shake classes that extend from Iterator:

  // This can now be tree-shaken by esbuild:
  class ExampleIterator extends Iterator {}

• Add support for the new @view-transition CSS rule (#4313)

  With this release, esbuild now has improved support for pretty-printing and minifying the new @view-transition rule (which esbuild was previously unaware of):

  /* Original code */
  @view-transition {
    navigation: auto;
    types: check;
  }
  
  /* Old output */
  @view-transition { navigation: auto; types: check; }
  
  /* New output */
  @view-transition {
    navigation: auto;
    types: check;
  }

  The new view transition feature provides a mechanism for creating animated transitions between documents in a multi-page app. You can read more about view transition rules here.

  This change was contributed by @yisibl.

• Trim CSS rules that will never match

  The CSS minifier will now remove rules whose selectors contain :is() and :where() as those selectors will never match. These selectors can currently be automatically generated by esbuild when you give esbuild nonsensical input such as the following:

  /* Original code */
  div:before {
    color: green;
    &.foo {
      color: red;
    }
  }
  
  /* Old output (with --supported:nesting=false --minify) */
  div:before{color:green}:is().foo{color:red}
  
  /* New output (with --supported:nesting=false --minify) */
  div:before{color:green}

  This input is nonsensical because CSS nesting is (unfortunately) not supported inside of pseudo-elements such as :before. Currently esbuild generates a rule containing :is() in this case when you tell esbuild to transform nested CSS into non-nested CSS. I think it's reasonable to do that as it sort of helps explain what's going on (or at least indicates that something is wrong in the output). It shouldn't be present in minified code, however, so this release now strips it out.

0.25.11

• Add support for with { type: 'bytes' } imports (#4292)

  The import bytes proposal has reached stage 2.7 in the TC39 process, which means that although it isn't quite recommended for implementation, it's generally approved and ready for validation. Furthermore it has already been implemented by Deno and Webpack. So with this release, esbuild will also add support for this. It behaves exactly the same as esbuild's existing binary loader. Here's an example:

  import data from './image.png' with { type: 'bytes' }
  const view = new DataView(data.buffer, 0, 24)
  const width = view.getInt32(16)
  const height = view.getInt32(20)
  console.log('size:', width + '\xD7' + height)

• Lower CSS media query range syntax (#3748, #4293)

  With this release, esbuild will now transform CSS media query range syntax into equivalent syntax using min-/max- prefixes for older browsers. For example, the following CSS:

  @media (640px <= width <= 960px) {
    main {
      display: flex;
    }
  }

  will be transformed like this with a target such as --target=chrome100 (or more specifically with --supported:media-range=false if desired):

  @media (min-width: 640px) and (max-width: 960px) {
    main {
      display: flex;
    }
  }

0.25.10

• Fix a panic in a minification edge case (#4287)

  This release fixes a panic due to a null pointer that could happen when esbuild inlines a doubly-nested identity function and the final result is empty. It was fixed by emitting the value undefined in this case, which avoids the panic. This case must be rare since it hasn't come up until now. Here is an example of code that previously triggered the panic (which only happened when minifying):

  function identity(x) { return x }
  identity({ y: identity(123) })

• Fix @supports nested inside pseudo-element (#4265)

  When transforming nested CSS to non-nested CSS, esbuild is supposed to filter out pseudo-elements such as ::placeholder for correctness. The CSS nesting specification says the following:

  The nesting selector cannot represent pseudo-elements (identical to the behavior of the ':is()' pseudo-class). We’d like to relax this restriction, but need to do so simultaneously for both ':is()' and '&', since they’re intentionally built on the same underlying mechanisms.

  However, it seems like this behavior is different for nested at-rules such as @supports, which do work with pseudo-elements. So this release modifies esbuild's behavior to now take that into account:

  /* Original code */
  ::placeholder {
    color: red;
    body & { color: green }
    @supports (color: blue) { color: blue }
  }
  
  /* Old output (with --supported:nesting=false) */
  ::placeholder {
    color: red;
  }
  body :is() {
    color: green;
  }
  @supports (color: blue) {
     {
      color: blue;
    }
  }
  
  /* New output (with --supported:nesting=false) */
  ::placeholder {
    color: red;
  }
  body :is() {
    color: green;
  }
  @supports (color: blue) {
    ::placeholder {
      color: blue;
    }
  }

Does any of this look wrong? Please let us know.

See the full diff on Github. The new version differs by 64 commits:

• publish 0.27.2 to npm
• additional tests for `switch` with `break`
• update release notes
• fix #4357: -webkit- prefix for mask shorthand (#4358)
• compat table: update `@types/node`
• compat table: fix a type error with the new types
• fix `make compat-table` to install dependencies
• release notes for #4361
• fix: allow subpath imports that start with `#/` (#4361)
• minify some switch statements to if-else statement
• fix #4176: improve switch statement partial-eval
• introduce more helper methods
• fix some extremely subtle switch minification bugs
• introduce a helper method
• fix #4359: prune empty `case` before a `default`
• fix #4323: forbid `using` inside `switch` clauses
• close #4362, close #4363: update to go 1.25.5
• publish 0.27.1 to npm
• fix #4354: improve IIFE inlining for expressions
• minify: move unused expr simplification later
• fix #4353: remove empty `try`/`finally` clauses
• fix #4348: bundler bug with `var` inside `if`
• fix #4351: label + `try` + `for` minifier bug
• fix: deno release url wrong comment (#4326)
• calling `Symbol.for` with a primitive never throws
• update `decorator-tests.js` snapshot
• calling `Symbol` with a primitive will never throw
• publish 0.27.0 to npm
• fix #4286: use `Uint8Array.fromBase64` if present (#4295)
• update go 1.25.3 => 1.25.4
• update go 1.23.12 => 1.25.3 (#4318)
• use a patched go compiler for release builds
• delete temporary `release.yml` workflow
• add a temporary `release.yml` workflow
• fix `publish.yml`
• publish 0.26.0 to npm
• enable trusted publishing (#4319)
• some deno-related fixes
• add a dummy `publish.yml`
• publish 0.25.12 to npm
• update release notes
• minify: remove css rules containing empty `:is()`
• add some additional known static methods
• automatically mark "RegExp.escape()" calls as pure
• simplify some call expression checks
• add some additional known static methods
• fix #4310: add `Iterator` and other known globals
• fix: escape dev server breadcrumb hrefs properly (#4316)
• fix #4315: `@media` deduplication bug edge case
• update release notes
• feat: add CSS `@view-transition` (#4313)
• publish 0.25.11 to npm
• css: also parse media queries in `@import` rules
• css: some adjustments to `@import` parsing
• fix #3748, fix #4293: lower css media range syntax
• css: parse and print media queries
• run `make update-compat-table`
• fix #4292: support `with { type: bytes }`
• publish 0.25.10 to npm
• refactor: use strings.Builder (#4290)
• run `make update-compat-table`
• fix #4287: marked the wrong issue as fixed
• fix #4286: minifier panic due to identity function
• fix #4265: `@supports` nested inside `::pseudo`