fix: web-core background thread module coverage

[PupilTong]

Summary by CodeRabbit

• Chores
  • Expanded test coverage reporting to discover and aggregate coverage from additional source files
  • Enabled source map generation for JavaScript and CSS in the build output
  • Updated package distribution to exclude all source map files from published releases

Checklist

• Tests updated (or not required).
• Documentation updated (or not required).
• Changeset added, and when a BREAKING CHANGE occurs, it needs to be clearly marked (or not required).

[coderabbitai]

📝 Walkthrough

Walkthrough

Enhanced code coverage analysis by enabling source map generation in the build pipeline, expanding coverage fixture discovery to include web-core mapped files, and broadening package exclusion patterns to encompass all source map artifacts instead of JavaScript-only maps.

Changes

Cohort / File(s)	Summary
Coverage Fixture Enhancement packages/web-platform/playwright-fixtures/src/coverage-fixture.ts	Added getWebCoreMappedFiles() function to recursively discover .map files in web-core/dist/client_prod. Modified coverage conversion to iterate over multiple resolved source paths (original candidates plus discovered files) and aggregate Istanbul coverage from each via Object.assign instead of processing a single path.
Build and Package Configuration packages/web-platform/web-core/rsbuild.config.ts, packages/web-platform/web-core/package.json	Enabled source map generation for both JavaScript (js: 'source-map') and CSS (css: true) in rsbuild output configuration. Updated package.json exclusion pattern from !dist/**/*.js.map to !dist/**/*.map to exclude all source map types from published artifacts.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

• chore: add playwright fixtures package with initial configuration and … #2050: Modifies the same coverage-fixture file and adjusts how Playwright JavaScript coverage is resolved and processed.

Suggested labels

platform:Web

Suggested reviewers

• Sherry-hue
• colinaaa

Poem

🐰 Whiskers twitching with delight,
Maps are born and coverage takes flight,
From source to spread across the land,
Web-core discovered, perfectly planned! ✨📍

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and specifically describes the main objective of the changeset: improving coverage detection for the web-core background thread module by discovering additional source files dynamically.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[codecov]

Codecov Report

❌ Patch coverage is 0% with 35 lines in your changes missing coverage. Please review.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
...atform/playwright-fixtures/src/coverage-fixture.ts	0.00%	31 Missing ⚠️
packages/web-platform/web-core/rsbuild.config.ts	0.00%	4 Missing ⚠️

📢 Thoughts on this report? Let us know!

[coderabbitai]

🧹 Nitpick comments (1)

packages/web-platform/playwright-fixtures/src/coverage-fixture.ts (1)

24-33: Minor: Redundant type assertion after filter.

The type assertion (f as string) on line 29 is redundant since the filter already narrows the type to string.

♻️ Suggested simplification

 const getWebCoreMappedFiles = () => {
   try {
     const files = readdirSync(webCoreDist, { recursive: true });
     return files
       .filter((f) => typeof f === 'string' && f.endsWith('.map'))
-      .map((f) => path.join(webCoreDist, (f as string).replace(/\.map$/, '')));
+      .map((f) => path.join(webCoreDist, f.replace(/\.map$/, '')));
   } catch (e) {
     return [];
   }
 };

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@packages/web-platform/playwright-fixtures/src/coverage-fixture.ts` around
lines 24 - 33, In getWebCoreMappedFiles, remove the redundant type assertion "(f
as string)" because the prior filter already narrows f to string; update the
.map call to use f directly (e.g., path.join(webCoreDist, f.replace(/\.map$/,
''))) while keeping the try/catch, readdirSync usage, and path.join(webCoreDist,
...) logic intact so behavior is unchanged.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Nitpick comments:
In `@packages/web-platform/playwright-fixtures/src/coverage-fixture.ts`:
- Around line 24-33: In getWebCoreMappedFiles, remove the redundant type
assertion "(f as string)" because the prior filter already narrows f to string;
update the .map call to use f directly (e.g., path.join(webCoreDist,
f.replace(/\.map$/, ''))) while keeping the try/catch, readdirSync usage, and
path.join(webCoreDist, ...) logic intact so behavior is unchanged.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: 69129ad2-07eb-4d87-904d-722c8fea05ed

📥 Commits

Reviewing files that changed from the base of the PR and between 7332eb4 and 513787d.

📒 Files selected for processing (3)

• packages/web-platform/playwright-fixtures/src/coverage-fixture.ts
• packages/web-platform/web-core/package.json
• packages/web-platform/web-core/rsbuild.config.ts

[codspeed-hq]

Merging this PR will degrade performance by 42.92%

❌ 1 regressed benchmark
✅ 80 untouched benchmarks
⏩ 21 skipped benchmarks¹

⚠️ Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
❌	basic-performance-text-200	11.8 ms	20.7 ms	-42.92%

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_{Comparing PupilTong:p/hw/fix-coverage-after-use-html-head (513787d) with main (7332eb4)}

Footnotes

1. 21 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[relativeci]

Web Explorer

#8873 Bundle Size — 749.3KiB (0%).

513787d(current) vs 7332eb4 main#8857(baseline)

Bundle metrics   2 changes

	Current #8873	Baseline #8857
Initial JS	44.45KiB	44.45KiB
Initial CSS	2.16KiB	2.16KiB
Cache Invalidation	0%	0%
Chunks	8	8
Assets	10	10
Modules	148(-1.33%)	150
Duplicate Modules	11	11
Duplicate Code	35.01%(+0.03%)	35%
Packages	3	3
Duplicate Packages	0	0

Bundle size by type  no changes

	Current #8873	Baseline #8857
Other	401.63KiB	401.63KiB
JS	345.51KiB	345.51KiB
CSS	2.16KiB	2.16KiB

Bundle analysis report Branch PupilTong:p/hw/fix-coverage-afte... Project dashboard

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^{Generated by RelativeCI Documentation Report issue}

[relativeci]

React MTF Example

#432 Bundle Size — 192.85KiB (0%).

513787d(current) vs 7332eb4 main#416(baseline)

Bundle metrics  no changes

	Current #432	Baseline #416
Initial JS	0B	0B
Initial CSS	0B	0B
Cache Invalidation	0%	0%
Chunks	0	0
Assets	3	3
Modules	173	173
Duplicate Modules	67	67
Duplicate Code	45.36%	45.36%
Packages	2	2
Duplicate Packages	0	0

Bundle size by type  no changes

	Current #432	Baseline #416
IMG	111.23KiB	111.23KiB
Other	81.61KiB	81.61KiB

Bundle analysis report Branch PupilTong:p/hw/fix-coverage-afte... Project dashboard

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[relativeci]

React External

#417 Bundle Size — 582.81KiB (0%).

513787d(current) vs 7332eb4 main#401(baseline)

Bundle metrics  no changes

	Current #417	Baseline #401
Initial JS	0B	0B
Initial CSS	0B	0B
Cache Invalidation	0%	0%
Chunks	0	0
Assets	3	3
Modules	17	17
Duplicate Modules	5	5
Duplicate Code	8.59%	8.59%
Packages	0	0
Duplicate Packages	0	0

Bundle size by type  no changes

	Current #417	Baseline #401
Other	582.81KiB	582.81KiB

Bundle analysis report Branch PupilTong:p/hw/fix-coverage-afte... Project dashboard

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^{Generated by RelativeCI Documentation Report issue}

[relativeci]

React Example

#7299 Bundle Size — 223.58KiB (0%).

513787d(current) vs 7332eb4 main#7283(baseline)

Bundle metrics  no changes

	Current #7299	Baseline #7283
Initial JS	0B	0B
Initial CSS	0B	0B
Cache Invalidation	0%	0%
Chunks	0	0
Assets	4	4
Modules	179	179
Duplicate Modules	70	70
Duplicate Code	45.76%	45.76%
Packages	2	2
Duplicate Packages	0	0

Bundle size by type  no changes

	Current #7299	Baseline #7283
IMG	145.76KiB	145.76KiB
Other	77.82KiB	77.82KiB

Bundle analysis report Branch PupilTong:p/hw/fix-coverage-afte... Project dashboard

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