Bundler support track

[fi3ework]

Bundler supports

Tracking the bundler supports for the optimal artifact (webpack[^1] and Rspack).

[^1]: Reference: https://github.com/webpack/webpack/issues/17121

CJS support

ESM artifacts won't break by scope isolation when bundling module bailout from concatenation (usually CJS module).

• [x] webpack: https://github.com/webpack/webpack/pull/18348
• [x] Rspack: https://github.com/web-infra-dev/rspack/pull/6697

Tree shakable export

ESM artifacts should be tree-shakable.

• [x] webpack: https://github.com/webpack/webpack/pull/18272
• [x] Rspack: https://github.com/web-infra-dev/rspack/pull/6877

Remove unnecessary webpack exports runtime

• [x] webpack: https://github.com/webpack/webpack/pull/18338
• [x] webpack: https://github.com/webpack/webpack/pull/18565
• [x] Rspack: https://github.com/web-infra-dev/rspack/pull/7102

Externals ^P0

Externalized module import / dynamic import will introduce redundant runtime in webpack / Rspack. Dynamic import will be hoisted to the top level (https://github.com/webpack/webpack/issues/17986). Furthermore, the import and import() should be leave unchanged.

• [x] support "module-import" external type
  • [x] webpack: https://github.com/webpack/webpack/pull/18620
  • [x] Rspack: https://github.com/web-infra-dev/rspack/pull/7479
• [x] Rspack misaligned: Port https://github.com/webpack/webpack/pull/18338. However, the simple module remapping runtime in Rspack (https://github.com/web-infra-dev/rspack/blob/main/crates/rspack_core/src/external_module.rs#L266-L269) is totally unused now.
  • [x] Rspack: https://github.com/web-infra-dev/rspack/pull/7533
• [x] dynamic external introduce webpack runtime
  • [x] Rspack: https://github.com/web-infra-dev/rspack/pull/7759
• [x] In concatenated module, static external module namespace import re-assign breaks tree shaking (demo)
  • [x] Rspack: https://github.com/web-infra-dev/rspack/pull/7839
• [x] Not work with star export from external module (bundleless) https://github.com/webpack/webpack/issues/15270
  • [x] Rspack: https://github.com/web-infra-dev/rspack/pull/8217
• [x] preserve import() when import() is supported in that Node.js version in CJS. (BLOCK: can't distinguish static / dynamic from external callback except adding new information) https://github.com/webpack/webpack/discussions/16272
  • [ ] webpack: https://redirect.github.com/webpack/webpack/pull/18784
  • [x] Rspack: https://github.com/web-infra-dev/rspack/pull/8414

Dynamic import (Chunk splitting) ^P1

Can't be static analysis because of the public path runtime.

• [ ] https://github.com/webpack/webpack/issues/15697
• [ ] https://github.com/webpack/webpack/issues/12801

Preserve CSS Import

CSS import statement will be extracted out.

Node.js Shims

• [x] https://github.com/web-infra-dev/rspack/pull/7465

Miscellaneous

require

• [x] Rspack: https://github.com/web-infra-dev/rspack/pull/7939

require and require.resolve

• ESM:
  • [x] require(...) should be either behave like esbuild (sniff and throw as a fallback) or be shimmed with createRequire.
  • [x] require.resolve(...) should be either behave like esbuild (sniff and throw as a fallback) or be shimmed with createRequire.
• CJS:
  • [x] require(...) with externals should work like __non_webpack_require__
  • [x] require.resolve(...) should preserve as-is.
  • [x] preserve require('./' + expression + '.js') like dynamic require with expression. (BLOCK: https://github.com/microsoft/rushstack/blob/main/webpack/preserve-dynamic-require-plugin/README.md not available in Rspack as succeedModule is readonly in JS side)

Extra runtime when bundling single module

• [x] Rspack: https://github.com/web-infra-dev/rspack/pull/7317
• [x] Rspack: https://github.com/web-infra-dev/rspack/pull/7394

Re-export with property access or eval

• [x] Rspack: https://github.com/web-infra-dev/rspack/pull/7394

Multiple entries ^P2

Export in library works only for last entry module

• [ ] https://github.com/webpack/webpack/issues/15936

[fi3ework]

🚧 ESM output quality track

Not aim to strict alignment with esbuild, compare the differences between esbuild artifacts and create a more compact output.