evanw/esbuild v0.24.1

on GitHub

Allow es2024 as a target in tsconfig.json (#4004)

TypeScript recently added es2024 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": "ES2024"
  }
}

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.

This fix was contributed by @billyjanitsch.

Allow automatic semicolon insertion after get/set

This change fixes a grammar bug in the parser that incorrectly treated the following code as a syntax error:

class Foo {
  get
  *x() {}
  set
  *y() {}
}

The above code will be considered valid starting with this release. This change to esbuild follows a similar change to TypeScript which will allow this syntax starting with TypeScript 5.7.

Allow quoted property names in --define and --pure (#4008)

The define and pure API options now accept identifier expressions containing quoted property names. Previously all identifiers in the identifier expression had to be bare identifiers. This change now makes --define and --pure consistent with --global-name, which already supported quoted property names. For example, the following is now possible:

// The following code now transforms to "return true;\n"
console.log(esbuild.transformSync(
  `return process.env['SOME-TEST-VAR']`,
  { define: { 'process.env["SOME-TEST-VAR"]': 'true' } },
))

Note that if you're passing values like this on the command line using esbuild's --define flag, then you'll need to know how to escape quote characters for your shell. You may find esbuild's JavaScript API more ergonomic and portable than writing shell code.

Minify empty try/catch/finally blocks (#4003)

With this release, esbuild will now attempt to minify empty try blocks:

// Original code
try {} catch { foo() } finally { bar() }

// Old output (with --minify)
try{}catch{foo()}finally{bar()}

// New output (with --minify)
bar();

This can sometimes expose additional minification opportunities.

Include entryPoint metadata for the copy loader (#3985)

Almost all entry points already include a entryPoint field in the outputs map in esbuild's build metadata. However, this wasn't the case for the copy loader as that loader is a special-case that doesn't behave like other loaders. This release adds the entryPoint field in this case.

Source mappings may now contain null entries (#3310, #3878)

With this change, sources that result in an empty source map may now emit a null source mapping (i.e. one with a generated position but without a source index or original position). This change improves source map accuracy by fixing a problem where minified code from a source without any source mappings could potentially still be associated with a mapping from another source file earlier in the generated output on the same minified line. It manifests as nonsensical files in source mapped stack traces. Now the null mapping "resets" the source map so that any lookups into the minified code without any mappings resolves to null (which appears as the output file in stack traces) instead of the incorrect source file.

This change shouldn't affect anything in most situations. I'm only mentioning it in the release notes in case it introduces a bug with source mapping. It's part of a work-in-progress future feature that will let you omit certain unimportant files from the generated source map to reduce source map size.

Avoid using the parent directory name for determinism (#3998)

To make generated code more readable, esbuild includes the name of the source file when generating certain variable names within the file. Specifically bundling a CommonJS file generates a variable to store the lazily-evaluated module initializer. However, if a file is named index.js (or with a different extension), esbuild will use the name of the parent directory instead for a better name (since many packages have files all named index.js but have unique directory names).

This is problematic when the bundle entry point is named index.js and the parent directory name is non-deterministic (e.g. a temporary directory created by a build script). To avoid non-determinism in esbuild's output, esbuild will now use index instead of the parent directory in this case. Specifically this will happen if the parent directory is equal to esbuild's outbase API option, which defaults to the lowest common ancestor of all user-specified entry point paths.

Experimental support for esbuild on NetBSD (#3974)

With this release, esbuild now has a published binary executable for NetBSD in the @esbuild/netbsd-arm64 npm package, and esbuild's installer has been modified to attempt to use it when on NetBSD. Hopefully this makes installing esbuild via npm work on NetBSD. This change was contributed by @bsiegert.

⚠️ Note: NetBSD is not one of Node's supported platforms, so installing esbuild may or may not work on NetBSD depending on how Node has been patched. This is not a problem with esbuild. ⚠️