Update dependency esbuild to v0.25.5

[renovate]

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
esbuild	0.25.0 -> 0.25.5

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Release Notes

evanw/esbuild (esbuild)

v0.25.5

Compare Source

• Fix a regression with browser in package.json (#​4187)

  The fix to #​4144 in version 0.25.3 introduced a regression that caused browser overrides specified in package.json to fail to override relative path names that end in a trailing slash. That behavior change affected the [email protected] package. This regression has been fixed, and now has test coverage.

• Add support for certain keywords as TypeScript tuple labels (#​4192)

  Previously esbuild could incorrectly fail to parse certain keywords as TypeScript tuple labels that are parsed by the official TypeScript compiler if they were followed by a ? modifier. These labels included function, import, infer, new, readonly, and typeof. With this release, these keywords will now be parsed correctly. Here's an example of some affected code:

  type Foo = [
    value: any,
    readonly?: boolean, // This is now parsed correctly
  ]

• Add CSS prefixes for the stretch sizing value (#​4184)

  This release adds support for prefixing CSS declarations such as div { width: stretch }. That CSS is now transformed into this depending on what the --target= setting includes:

  div {
    width: -webkit-fill-available;
    width: -moz-available;
    width: stretch;
  }

v0.25.4

Compare Source

• Add simple support for CORS to esbuild's development server (#​4125)

  Starting with version 0.25.0, esbuild's development server is no longer configured to serve cross-origin requests. This was a deliberate change to prevent any website you visit from accessing your running esbuild development server. However, this change prevented (by design) certain use cases such as "debugging in production" by having your production website load code from localhost where the esbuild development server is running.

  To enable this use case, esbuild is adding a feature to allow Cross-Origin Resource Sharing (a.k.a. CORS) for simple requests. Specifically, passing your origin to the new cors option will now set the Access-Control-Allow-Origin response header when the request has a matching Origin header. Note that this currently only works for requests that don't send a preflight OPTIONS request, as esbuild's development server doesn't currently support OPTIONS requests.

  Some examples:

  • CLI:

    esbuild --servedir=. --cors-origin=https://example.com
    

  • JS:

    const ctx = await esbuild.context({})
    await ctx.serve({
      servedir: '.',
      cors: {
        origin: 'https://example.com',
      },
    })

  • Go:

    ctx, _ := api.Context(api.BuildOptions{})
    ctx.Serve(api.ServeOptions{
      Servedir: ".",
      CORS: api.CORSOptions{
        Origin: []string{"https://example.com"},
      },
    })

  The special origin * can be used to allow any origin to access esbuild's development server. Note that this means any website you visit will be able to read everything served by esbuild.

• Pass through invalid URLs in source maps unmodified (#​4169)

  This fixes a regression in version 0.25.0 where sources in source maps that form invalid URLs were not being passed through to the output. Version 0.25.0 changed the interpretation of sources from file paths to URLs, which means that URL parsing can now fail. Previously URLs that couldn't be parsed were replaced with the empty string. With this release, invalid URLs in sources should now be passed through unmodified.

• Handle exports named __proto__ in ES modules (#​4162, #​4163)

  In JavaScript, the special property name __proto__ sets the prototype when used inside an object literal. Previously esbuild's ESM-to-CommonJS conversion didn't special-case the property name of exports named __proto__ so the exported getter accidentally became the prototype of the object literal. It's unclear what this affects, if anything, but it's better practice to avoid this by using a computed property name in this case.

  This fix was contributed by @​magic-akari.

v0.25.3

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• Fix lowered async arrow functions before super() (#​4141, #​4142)

  This change makes it possible to call an async arrow function in a constructor before calling super() when targeting environments without async support, as long as the function body doesn't reference this. Here's an example (notice the change from this to null):

  // Original code
  class Foo extends Object {
    constructor() {
      (async () => await foo())()
      super()
    }
  }
  
  // Old output (with --target=es2016)
  class Foo extends Object {
    constructor() {
      (() => __async(this, null, function* () {
        return yield foo();
      }))();
      super();
    }
  }
  
  // New output (with --target=es2016)
  class Foo extends Object {
    constructor() {
      (() => __async(null, null, function* () {
        return yield foo();
      }))();
      super();
    }
  }

  Some background: Arrow functions with the async keyword are transformed into generator functions for older language targets such as --target=es2016. Since arrow functions capture this, the generated code forwards this into the body of the generator function. However, JavaScript class syntax forbids using this in a constructor before calling super(), and this forwarding was problematic since previously happened even when the function body doesn't use this. Starting with this release, esbuild will now only forward this if it's used within the function body.

  This fix was contributed by @​magic-akari.

• Fix memory leak with --watch=true (#​4131, #​4132)

  This release fixes a memory leak with esbuild when --watch=true is used instead of --watch. Previously using --watch=true caused esbuild to continue to use more and more memory for every rebuild, but --watch=true should now behave like --watch and not leak memory.

  This bug happened because esbuild disables the garbage collector when it's not run as a long-lived process for extra speed, but esbuild's checks for which arguments cause esbuild to be a long-lived process weren't updated for the new --watch=true style of boolean command-line flags. This has been an issue since this boolean flag syntax was added in version 0.14.24 in 2022. These checks are unfortunately separate from the regular argument parser because of how esbuild's internals are organized (the command-line interface is exposed as a separate Go API so you can build your own custom esbuild CLI).

  This fix was contributed by @​mxschmitt.

• More concise output for repeated legal comments (#​4139)

  Some libraries have many files and also use the same legal comment text in all files. Previously esbuild would copy each legal comment to the output file. Starting with this release, legal comments duplicated across separate files will now be grouped in the output file by unique comment content.

• Allow a custom host with the development server (#​4110)

  With this release, you can now use a custom non-IP host with esbuild's local development server (either with --serve= for the CLI or with the serve() call for the API). This was previously possible, but was intentionally broken in version 0.25.0 to fix a security issue. This change adds the functionality back except that it's now opt-in and only for a single domain name that you provide.

  For example, if you add a mapping in your /etc/hosts file from local.example.com to 127.0.0.1 and then use esbuild --serve=local.example.com:8000, you will now be able to visit http://local.example.com:8000/ in your browser and successfully connect to esbuild's development server (doing that would previously have been blocked by the browser). This should also work with HTTPS if it's enabled (see esbuild's documentation for how to do that).

• Add a limit to CSS nesting expansion (#​4114)

  With this release, esbuild will now fail with an error if there is too much CSS nesting expansion. This can happen when nested CSS is converted to CSS without nesting for older browsers as expanding CSS nesting is inherently exponential due to the resulting combinatorial explosion. The expansion limit is currently hard-coded and cannot be changed, but is extremely unlikely to trigger for real code. It exists to prevent esbuild from using too much time and/or memory. Here's an example:

  a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{color:red}}}}}}}}}}}}}}}}}}}}

  Previously, transforming this file with --target=safari1 took 5 seconds and generated 40mb of CSS. Trying to do that will now generate the following error instead:

  ✘ [ERROR] CSS nesting is causing too much expansion
  
      example.css:1:60:
        1 │ a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{a,b{color:red}}}}}}}}}}}}}}}}}}}}
          ╵                                                             ^
  
    CSS nesting expansion was terminated because a rule was generated with 65536 selectors. This limit
    exists to prevent esbuild from using too much time and/or memory. Please change your CSS to use
    fewer levels of nesting.
  

• Fix path resolution edge case (#​4144)

  This fixes an edge case where esbuild's path resolution algorithm could deviate from node's path resolution algorithm. It involves a confusing situation where a directory shares the same file name as a file (but without the file extension). See the linked issue for specific details. This appears to be a case where esbuild is correctly following node's published resolution algorithm but where node itself is doing something different. Specifically the step LOAD_AS_FILE appears to be skipped when the input ends with ... This release changes esbuild's behavior for this edge case to match node's behavior.

• Update Go from 1.23.7 to 1.23.8 (#​4133, #​4134)

  This should have no effect on existing code as this version change does not change Go's operating system support. It may remove certain reports from vulnerability scanners that detect which version of the Go compiler esbuild uses, such as for CVE-2025-22871.

  As a reminder, esbuild's development server is intended for development, not for production, so I do not consider most networking-related vulnerabilities in Go to be vulnerabilities in esbuild. Please do not use esbuild's development server in production.

v0.25.2

Compare Source

• Support flags in regular expressions for the API (#​4121)

  The JavaScript plugin API for esbuild takes JavaScript regular expression objects for the filter option. Internally these are translated into Go regular expressions. However, this translation previously ignored the flags property of the regular expression. With this release, esbuild will now translate JavaScript regular expression flags into Go regular expression flags. Specifically the JavaScript regular expression /\.[jt]sx?$/i is turned into the Go regular expression `(?i)\.[jt]sx?$` internally inside of esbuild's API. This should make it possible to use JavaScript regular expressions with the i flag. Note that JavaScript and Go don't support all of the same regular expression features, so this mapping is only approximate.

• Fix node-specific annotations for string literal export names (#​4100)

  When node instantiates a CommonJS module, it scans the AST to look for names to expose via ESM named exports. This is a heuristic that looks for certain patterns such as exports.NAME = ... or module.exports = { ... }. This behavior is used by esbuild to "annotate" CommonJS code that was converted from ESM with the original ESM export names. For example, when converting the file export let foo, bar from ESM to CommonJS, esbuild appends this to the end of the file:

  // Annotate the CommonJS export names for ESM import in node:
  0 && (module.exports = {
    bar,
    foo
  });

  However, this feature previously didn't work correctly for export names that are not valid identifiers, which can be constructed using string literal export names. The generated code contained a syntax error. That problem is fixed in this release:

  // Original code
  let foo
  export { foo as "foo!" }
  
  // Old output (with --format=cjs --platform=node)
  ...
  0 && (module.exports = {
    "foo!"
  });
  
  // New output (with --format=cjs --platform=node)
  ...
  0 && (module.exports = {
    "foo!": null
  });

• Basic support for index source maps (#​3439, #​4109)

  The source map specification has an optional mode called index source maps that makes it easier for tools to create an aggregate JavaScript file by concatenating many smaller JavaScript files with source maps, and then generate an aggregate source map by simply providing the original source maps along with some offset information. My understanding is that this is rarely used in practice. I'm only aware of two uses of it in the wild: ClojureScript and Turbopack.

  This release provides basic support for indexed source maps. However, the implementation has not been tested on a real app (just on very simple test input). If you are using index source maps in a real app, please try this out and report back if anything isn't working for you.

  Note that this is also not a complete implementation. For example, index source maps technically allows nesting source maps to an arbitrary depth, while esbuild's implementation in this release only supports a single level of nesting. It's unclear whether supporting more than one level of nesting is important or not given the lack of available test cases.

  This feature was contributed by @​clyfish.

v0.25.1

Compare Source

• Fix incorrect paths in inline source maps (#​4070, #​4075, #​4105)

  This fixes a regression from version 0.25.0 where esbuild didn't correctly resolve relative paths contained within source maps in inline sourceMappingURL data URLs. The paths were incorrectly being passed through as-is instead of being resolved relative to the source file containing the sourceMappingURL comment, which was due to the data URL not being a file URL. This regression has been fixed, and this case now has test coverage.

• Fix invalid generated source maps (#​4080, #​4082, #​4104, #​4107)

  This release fixes a regression from version 0.24.1 that could cause esbuild to generate invalid source maps. Specifically under certain conditions, esbuild could generate a mapping with an out-of-bounds source index. It was introduced by code that attempted to improve esbuild's handling of "null" entries in source maps (i.e. mappings with a generated position but no original position). This regression has been fixed.

  This fix was contributed by @​jridgewell.

• Fix a regression with non-file source map paths (#​4078)

  The format of paths in source maps that aren't in the file namespace was unintentionally changed in version 0.25.0. Path namespaces is an esbuild-specific concept that is optionally available for plugins to use to distinguish paths from file paths and from paths meant for other plugins. Previously the namespace was prepended to the path joined with a : character, but version 0.25.0 unintentionally failed to prepend the namespace. The previous behavior has been restored.

• Fix a crash with switch optimization (#​4088)

  The new code in the previous release to optimize dead code in switch statements accidentally introduced a crash in the edge case where one or more switch case values include a function expression. This is because esbuild now visits the case values first to determine whether any cases are dead code, and then visits the case bodies once the dead code status is known. That triggered some internal asserts that guard against traversing the AST in an unexpected order. This crash has been fixed by changing esbuild to expect the new traversal ordering. Here's an example of affected code:

  switch (x) {
    case '':
      return y.map(z => z.value)
    case y.map(z => z.key).join(','):
      return []
  }

• Update Go from 1.23.5 to 1.23.7 (#​4076, #​4077)

  This should have no effect on existing code as this version change does not change Go's operating system support. It may remove certain reports from vulnerability scanners that detect which version of the Go compiler esbuild uses.

  This PR was contributed by @​MikeWillCook.

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