fix(@angular/build): count statically imported chunks in the initial total

[imaksp]

Fixes #33773

Problem

optimizeChunks drops every used chunk from initialFiles, keeping only the main entry:

for (const usedFile of usedChunks) {
  if (usedFile === mainFile) {
    entriesToAnalyze.push([mainFile, original.initialFiles.get(mainFile)!]);
    continue;
  }
  original.initialFiles.delete(usedFile);
}

It then re-walks the optimized graph to restore the chunks the entry still imports statically — but the record it builds is never written back to the map:

const record = createInitialFileRecord(entryRecord.depth + 1);

entriesToAnalyze.push([importPath, record]);   // record is never stored

Since those entries were just deleted, existingRecord is always undefined, so every chunk is analyzed and then discarded. initialFiles ends up containing only the configured entry points, which is exactly what "Initial total" sums — so chunks the browser must download before the app can run are excluded from the total and reported under "Lazy chunk files".

BundlerContext#bundle performs the equivalent walk in tools/esbuild/bundler-context.ts and does store the record before pushing:

initialFiles.set(initialImport.path, record);
if (!initialImport.external) {
  entriesToAnalyze.push([initialImport.path, record]);
}

This change aligns the optimizer with that behaviour.

Note the esbuild metafile is correct — --stats-json reports these as kind: "import-statement" from main. Only the post-optimization bookkeeping is wrong.

Effect

Same application, production build, only this line changed.

Before

Initial chunk files     | Names         |  Raw size | Estimated transfer size
main-32IOW7BN.js        | main          | 199.93 kB |                48.59 kB
styles-5EGQDBXI.css     | styles        | 149.33 kB |                19.43 kB
polyfills-6XSCAVXF.js   | polyfills     |  28.09 kB |                 7.74 kB

                        | Initial total | 377.35 kB |                75.76 kB

Lazy chunk files        | Names         |  Raw size | Estimated transfer size
chunk-BJebXLml.js       | -             | 919.49 kB |               222.35 kB   <-- imported statically by main

After

Initial chunk files     | Names         |  Raw size | Estimated transfer size
chunk-BJebXLml.js       | -             | 919.49 kB |               222.35 kB
main-32IOW7BN.js        | main          | 199.93 kB |                48.59 kB
styles-5EGQDBXI.css     | styles        | 149.33 kB |                19.43 kB
chunk-pTHVPgQM.js       | -             |  36.09 kB |                 9.84 kB
polyfills-6XSCAVXF.js   | polyfills     |  28.09 kB |                 7.74 kB
chunk-jpabHedg.js       | -             |   9.95 kB |                 3.24 kB
chunk-Dss6OLyd.js       | -             |   3.07 kB |                 1.25 kB
chunk-XzxpTrya.js       | -             |   2.28 kB |                 1.02 kB
chunk-qP99rXNo.js       | -             | 710 bytes |               710 bytes
chunk-BL5j3Uqh.js       | -             | 534 bytes |               534 bytes

                        | Initial total |   1.35 MB |               314.70 kB

Independently cross-checked by walking index.html through static import/from edges only (skipping import()): 1172.0 kB of JS plus 149.3 kB of CSS, matching the corrected total.

Beyond the reported number, this also feeds generateIndexHtml and the server manifest's initial-files set, so those consume the same corrected map.

On test coverage

I was not able to build a fixture that exercises this path, and I would appreciate guidance.

The failure is only observable when the optimizer's output still contains main -> chunk static edges. In small applications Rolldown hoists all entry-reachable shared code into the main chunk, so no such chunk survives to be lost — which chunk-optimization-server_spec.ts already relies on, asserting hasFileMatch('dist/browser', /^chunk-/) is false as proof the pass ran.

I tried a fresh ng new on 22.1.3 across several shapes — 1 and 8 lazy routes, a shared component, a ~2 MB shared module producing a 1.72 MB main, and eight ~154 kB lazy routes sharing vendor code — and every one produced zero static chunks from main, leaving nothing to misreport. The affected application has ~114 lazy chunks.

If a fixture shape that retains a shared chunk would be acceptable, or if you would prefer a unit test asserting the invariant directly (every importsPerFile[mainFile] entry present in initialFiles after optimizeChunks), I am happy to add it.

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[gemini-code-assist]

Code Review

This pull request updates the chunk optimizer in the Angular build package to register the newly created file record in the 'original.initialFiles' map before pushing it to the analysis queue. I have no feedback to provide as there are no review comments.

[alan-agius4]

LGTM

[alan-agius4]

This PR was merged into the repository. The changes were merged into the following branches:

• main: 04b5327
• 22.1.x: 46fcb29