[edbzn]

Summary

Fixes #595.

In production builds, @oxc-angular/vite-optimizer ran optimizeAngularPackage(..., { markPure: true }) on every fesm20* file and ignored the package's sideEffects. Top-level calls that exist only for their side effects got /* @__PURE__ */ and were tree-shaken:

• zone.js (no sideEffects field) bundled to nothing, so a zone-based app failed with NG0908 at bootstrap.
• @angular/compiler ("sideEffects": ["./fesm2022/compiler.mjs"]) lost publishFacade(_global), so JIT failed with JIT compiler unavailable.

What changed

The optimizer plugin now passes markPure: true only for files under node_modules/@angular/ whose nearest package.json marks them side-effect-free. Everything else gets markPure: false. Metadata elision, static member wrapping and enum adjustment run as before.

sideEffects is read from the nearest package.json, cached per directory, and matched the way Vite's resolver matches it: a boolean as is, [] as side-effect-free, and array patterns through createFilter relative to the package directory, with **/ prepended to patterns that have no /. this.getModuleInfo(id).moduleSideEffects can't be used here: in a Vite 8.3.4 build it is null in the transform hook for zone.js, @angular/core and @angular/compiler.

How it matches the Angular CLI

In @angular/build (22.2), javascript-transformer-worker.js computes safeAngularPackage = sideEffects === false && /[\\/]node_modules[\\/]@angular[\\/]/.test(filename), and only safe packages get top-level pure annotations (topLevelSafeMode = !safeAngularPackage). sideEffects comes from esbuild's build.resolve(), which applies the package.json field. Metadata elision, static member wrapping and enum adjustment run for every file, so they stay ungated here too.

Two differences remain:

• Non-Angular packages that declare "sideEffects": false (e.g. @ngrx/store) no longer get top-level pure annotations, as in the Angular CLI. Those modules are still dropped whole when unused.
• In safe mode, the Angular CLI still annotates new on a short list of known side-effect-free constructors. This PR doesn't port that.

Verification

• New test/build-optimizer.test.ts drives the plugin on fixture packages written to a temp dir. Cases: a package without sideEffects, sideEffects: false, an array that matches the file, an array that doesn't, a pattern with no /, [], a side-effect-free non-@angular package, and static member wrapping in a side-effectful package. 4 of the 8 tests fail on main; all pass with the fix.
• pnpm test (455 passed), pnpm check, tsc -p tsconfig.json.
• Real vite build (Vite 8.3.4, Angular 22.2.0, zone.js 0.16.0) of an app that imports zone.js and @angular/compiler and uses provideZoneChangeDetection():
  • With @oxc-angular/vite@0.0.42, the bundle has no loadZone()/patchCommon()/publishFacade() calls, and the app throws NG0908 at bootstrap.
  • With this branch, all of those calls are in the bundle, a setTimeout in the component runs in the angular zone and updates the view, and ng.ɵcompilerFacade is set.
• A zoneless app (@angular/core + @angular/platform-browser only) builds to a byte-identical bundle with 0.0.42 and with this branch.

Maintainer follow-up

Merged main (#598) into the branch, then polished after a review pass:

• Reading package.json can no longer turn off the whole optimizer for a file. A BOM is stripped, non-string sideEffects entries are ignored, and an unreadable file counts as having side effects. Metadata elision, static wrapping and enum adjustment still run.
• The doc comment now says what the lookup follows: nearest package.json and esbuild-style matching, like the Angular CLI. Vite 8 (rolldown) reads only the package root, but real Angular 22 packages give the same answer either way (68 resolved @angular ids checked, 0 differences).
• Tests use forward-slash ids like Vite (Windows CI) and read fixtures from disk. They now also cover an @angular package with no sideEffects field (the actual cause of optimizer: markPure ignores package sideEffects, tree-shakes zone.js and @angular/compiler in production builds #595), sideEffects: true, a BOM, broken JSON, and mixed arrays.

Open questions, not changed here:

• AOT apps that call platformBrowserDynamic() now keep @angular/compiler (about 240 KB → 698 KB minified), because its publishFacade is no longer dropped. That is correct for optimizer: markPure ignores package sideEffects, tree-shakes zone.js and @angular/compiler in production builds #595. The Angular CLI avoids it by rewriting the AOT bootstrap to platformBrowser(), which this plugin doesn't do. Follow-up?
• In safe mode the CLI still marks new InjectionToken(...) pure (sideEffectFreeConstructors). Not ported, as noted above.
• Lookup rule: keep nearest package.json (CLI/esbuild), or read the package root like Vite 8?

🤖 Generated with Claude Code

[Brooooooklyn]

@codex review

[chatgpt-codex-connector]

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Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-10-22T04:05:36.381195Z	0a10cd8	Manual request

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[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. Already looking forward to the next diff.

Reviewed commit: 0a10cd8344

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