evanw/esbuild v0.11.4

on GitHub

Avoid name collisions with TypeScript helper functions (#1102)

Helper functions are sometimes used when transforming newer JavaScript syntax for older browsers. For example, let {x, ...y} = {z} is transformed into let _a = {z}, {x} = _a, y = __rest(_a, ["x"]) which uses the __rest helper function. Many of esbuild's transforms were modeled after the transforms in the TypeScript compiler, so many of the helper functions use the same names as TypeScript's helper functions.

However, the TypeScript compiler doesn't avoid name collisions with existing identifiers in the transformed code. This means that post-processing esbuild's output with the TypeScript compiler (e.g. for lowering ES6 to ES5) will cause issues since TypeScript will fail to call its own helper functions: microsoft/TypeScript#43296. There is also a problem where TypeScript's tslib library overwrites globals with these names, which can overwrite esbuild's helper functions if code bundled with esbuild is run in the global scope.

To avoid these problems, esbuild will now use different names for its helper functions.

Fix a chunk hashing issue (#1099)

Previously the chunk hashing algorithm skipped hashing entry point chunks when the --entry-names= setting doesn't contain [hash], since the hash wasn't used in the file name. However, this is no longer correct with the change in version 0.11.0 that made dynamic entry point chunks use --chunk-names= instead of --entry-names= since --chunk-names= can still contain [hash].

With this release, chunk contents will now always be hashed regardless of the chunk type. This makes esbuild somewhat slower than before in the common case, but it fixes this correctness issue.