Update esbuild 0.27.3 → 0.28.0 (major)

[depfu]

Here is everything you need to know about this upgrade. Please take a good look at what changed and the test results before merging this pull request.

What changed?

✳️ esbuild (0.27.3 → 0.28.0) · Repo · Changelog

Release Notes

0.28.0

• Add support for with { type: 'text' } imports (#4435)

  The import text proposal has reached stage 3 in the TC39 process, which means that it's recommended for implementation. It has also already been implemented by Deno and Bun. So with this release, esbuild also adds support for it. This behaves exactly the same as esbuild's existing text loader. Here's an example:

  import string from './example.txt' with { type: 'text' }
  console.log(string)

• Add integrity checks to fallback download path (#4343)

  Installing esbuild via npm is somewhat complicated with several different edge cases (see esbuild's documentation for details). If the regular installation of esbuild's platform-specific package fails, esbuild's install script attempts to download the platform-specific package itself (first with the npm command, and then with a HTTP request to registry.npmjs.org as a last resort).

  This last resort path previously didn't have any integrity checks. With this release, esbuild will now verify that the hash of the downloaded binary matches the expected hash for the current release. This means the hashes for all of esbuild's platform-specific binary packages will now be embedded in the top-level esbuild package. Hopefully this should work without any problems. But just in case, this change is being done as a breaking change release.

• Update the Go compiler from 1.25.7 to 1.26.1

  This upgrade should not affect anything. However, there have been some significant internal changes to the Go compiler, so esbuild could potentially behave differently in certain edge cases:

  • It now uses the new garbage collector that comes with Go 1.26.
  • The Go compiler is now more aggressive with allocating memory on the stack.
  • The executable format that the Go linker uses has undergone several changes.
  • The WebAssembly build now unconditionally makes use of the sign extension and non-trapping floating-point to integer conversion instructions.

  You can read the Go 1.26 release notes for more information.

0.27.7

• Fix lowering of define semantics for TypeScript parameter properties (#4421)

  The previous release incorrectly generated class fields for TypeScript parameter properties even when the configured target environment does not support class fields. With this release, the generated class fields will now be correctly lowered in this case:

  // Original code
  class Foo {
    constructor(public x = 1) {}
    y = 2
  }
  // Old output (with --loader=ts --target=es2021)
  
  class Foo {
  
  constructor(x = 1) {
  
  this.x = x;
  
  __publicField(this, "y", 2);
  
  }
  
  x;
  
  }
  // New output (with --loader=ts --target=es2021)
  
  class Foo {
  
  constructor(x = 1) {
  
  __publicField(this, "x", x);
  
  __publicField(this, "y", 2);
  
  }
  
  }

0.27.5

• Fix for an async generator edge case (#4401, #4417)

  Support for transforming async generators into the equivalent state machine was added in version 0.19.0. However, the generated state machine didn't work correctly when polling async generators concurrently, such as in the following code:

  async function* inner() { yield 1; yield 2 }
  async function* outer() { yield* inner() }
  let gen = outer()
  for await (let x of [gen.next(), gen.next()]) console.log(x)

  Previously esbuild's output of the above code behaved incorrectly when async generators were transformed (such as with --supported:async-generator=false). The transformation should be fixed starting with this release.

  This fix was contributed by @2767mr.

• Fix a regression when metafile is enabled (#4420, #4418)

  This release fixes a regression introduced by the previous release. When metafile: true was enabled in esbuild's JavaScript API, builds with build errors were incorrectly throwing an error about an empty JSON string instead of an object containing the build errors.

• Use define semantics for TypeScript parameter properties (#4421)

  Parameter properties are a TypeScript-specific code generation feature that converts constructor parameters into class fields when they are prefixed by certain keywords. When "useDefineForClassFields": true is present in tsconfig.json, the TypeScript compiler automatically generates class field declarations for parameter properties. Previously esbuild didn't do this, but esbuild will now do this starting with this release:

  // Original code
  class Foo {
    constructor(public x: number) {}
  }
  // Old output (with --loader=ts)
  
  class Foo {
  
  constructor(x) {
  
  this.x = x;
  
  }
  
  }
  // New output (with --loader=ts)
  
  class Foo {
  
  constructor(x) {
  
  this.x = x;
  
  }
  
  x;
  
  }

• Allow es2025 as a target in tsconfig.json (#4432)

  TypeScript recently added es2025 as a compilation target, so esbuild now supports this in the target field of tsconfig.json files, such as in the following configuration file:

  {
    "compilerOptions": {
      "target": "ES2025"
    }
  }

  As a reminder, the only thing that esbuild uses this field for is determining whether or not to use legacy TypeScript behavior for class fields. You can read more in the documentation.

0.27.4

• Fix a regression with CSS media queries (#4395, #4405, #4406)

  Version 0.25.11 of esbuild introduced support for parsing media queries. This unintentionally introduced a regression with printing media queries that use the <media-type> and <media-condition-without-or> grammar. Specifically, esbuild was failing to wrap an or clause with parentheses when inside <media-condition-without-or>. This release fixes the regression.

  Here is an example:

  /* Original code */
  @media only screen and ((min-width: 10px) or (min-height: 10px)) {
    a { color: red }
  }
  /* Old output (incorrect) */
  
  @media only screen and (min-width: 10px) or (min-height: 10px) {
  
  a {
  
  color: red;
  
  }
  
  }
  /* New output (correct) */
  
  @media only screen and ((min-width: 10px) or (min-height: 10px)) {
  
  a {
  
  color: red;
  
  }
  
  }

• Fix an edge case with the inject feature (#4407)

  This release fixes an edge case where esbuild's inject feature could not be used with arbitrary module namespace names exported using an export {} from statement with bundling disabled and a target environment where arbitrary module namespace names is unsupported.

  With the fix, the following inject file:

  import jquery from 'jquery';
  export { jquery as 'window.jQuery' };

  Can now always be rewritten as this without esbuild sometimes incorrectly generating an error:

  export { default as 'window.jQuery' } from 'jquery';

• Attempt to improve API handling of huge metafiles (#4329, #4415)

  This release contains a few changes that attempt to improve the behavior of esbuild's JavaScript API with huge metafiles (esbuild's name for the build metadata, formatted as a JSON object). The JavaScript API is designed to return the metafile JSON as a JavaScript object in memory, which makes it easy to access from within a JavaScript-based plugin. Multiple people have encountered issues where this API breaks down with a pathologically-large metafile.

  The primary issue is that V8 has an implementation-specific maximum string length, so using the JSON.parse API with large enough strings is impossible. This release will now attempt to use a fallback JavaScript-based JSON parser that operates directly on the UTF8-encoded JSON bytes instead of using JSON.parse when the JSON metafile is too big to fit in a JavaScript string. The new fallback path has not yet been heavily-tested. The metafile will also now be generated with whitespace removed if the bundle is significantly large, which will reduce the size of the metafile JSON slightly.

  However, hitting this case is potentially a sign that something else is wrong. Ideally you wouldn't be building something so enormous that the build metadata can't even fit inside a JavaScript string. You may want to consider optimizing your project, or breaking up your project into multiple parts that are built independently. Another option could potentially be to use esbuild's command-line API instead of its JavaScript API, which is more efficient (although of course then you can't use JavaScript plugins, so it may not be an option).

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

Commits

See the full diff on Github. The new version differs by 36 commits:

• publish 0.28.0 to npm
• fix #4435: support `with { type: text }` imports
• fix sort order in `snapshots_packagejson.txt`
• try to fix `test-old-ts`, also shuffle CI tasks
• use `''` instead of `null` to omit build hashes
• ci: allow missing binary hashes for tests
• Reapply "update go 1.25.7 => 1.26.1"
• fix #4343: integrity check for binary download
• publish 0.27.7 to npm
• fix typo in `Makefile` for `@esbuild/win32-x64`
• publish 0.27.6 to npm
• Revert "update go 1.25.7 => 1.26.1"
• run `make update-compat-table`
• remove an incorrect `else`
• fix #4421: lower generated class fields if needed
• ci: move `make test-old-ts`
• omit go's `buildvcs` for more reproducible builds
• organize `make platform-all` output in `Makefile`
• omit go's `buildid` for more reproducible builds
• update go 1.25.7 => 1.26.1
• update TS version for checking internal lib code
• publish 0.27.5 to npm
• split off `CHANGELOG-2025.md`
• fix #4421: use define for ts parameter props
• remove unused variable in `__asyncGenerator`
• update release notes
• fix: Handle non-awaited async generator (#4417)
• fix #4420, close #4418: `metafile` JSON regression
• fix #4432: add `es2025` as a valid target
• publish 0.27.4 to npm
• js api: fall back to js-based metafile json parser
• fix #4329: auto-minify metafile for large bundles
• fix #4415: add uint cast to stdio int parser
• chore: correct copy&paste panic message (#4399)
• fix #4407: incorrect error for inject edge case
• fix #4395 close #4405 close #4406: parens for `or`

---

Depfu will automatically keep this PR conflict-free, as long as you don't add any commits to this branch yourself. You can also trigger a rebase manually by commenting with @depfu rebase.

All Depfu comment commands

@​depfu rebase

Rebases against your default branch and redoes this update

@​depfu recreate

Recreates this PR, overwriting any edits that you've made to it

@​depfu merge

Merges this PR once your tests are passing and conflicts are resolved

@​depfu cancel merge

Cancels automatic merging of this PR

@​depfu close

Closes this PR and deletes the branch

@​depfu reopen

Restores the branch and reopens this PR (if it's closed)

@​depfu pause

Ignores all future updates for this dependency and closes this PR

@​depfu pause [minor|major]

Ignores all future minor/major updates for this dependency and closes this PR

@​depfu resume

Future versions of this dependency will create PRs again (leaves this PR as is)