esbuild 0.8.57

v0.8.57

on Node.js NPM

Fix overlapping chunk names when code splitting is active (#928)

Code splitting chunks use a content hash in their file name. This is good for caching because it means the file name is guaranteed to change if the chunk contents change, and the file name is guaranteed to stay the same if the chunk contents don't change (e.g. someone only modifies a comment). However, using a pure content hash can cause bugs if two separate chunks end up with the same contents.

A high-level example would be two identical copies of a library being accidentally collapsed into a single copy. While this results in a smaller bundle, this is incorrect because each copy might need to have its own state and so must be represented independently in the bundle.

This release fixes this issue by mixing additional information into the file name hash, which is no longer a content hash. The information includes the paths of the input files as well as the ranges of code within the file that are included in the chunk. File paths are used because they are a stable file identifier, but the relative path is used with / as the path separator to hopefully eliminate cross-platform differences between Unix and Windows.

Fix --keep-names for lowered class fields

Anonymous function expressions used in class field initializers are automatically assigned a .name property in JavaScript:

class Example {
  field1 = () => {}
  static field2 = () => {}
}
assert(new Example().field1.name === 'field1')
assert(Example.field2.name === 'field2')

This usually doesn't need special handling from esbuild's --keep-names option because esbuild doesn't modify field names, so the .name property will not change. However, esbuild will relocate the field initializer if the configured language target doesn't support class fields (e.g. --target=es6). In that case the .name property wasn't preserved even when --keep-names was specified. This bug has been fixed. Now the .name property should be preserved in this case as long as you enable --keep-names.

Enable importing certain data URLs in CSS and JavaScript

You can now import data URLs of type text/css using a CSS @import rule and import data URLs of type text/javascript and application/json using a JavaScript import statement. For example, doing this is now possible:

import 'data:text/javascript,console.log("hello!");';
import _ from 'data:application/json,"world!"';

This is for compatibility with node which supports this feature natively. Importing from a data URL is sometimes useful for injecting code to be evaluated before an external import without needing to generate a separate imported file.