[microsoft-playwright-automation]

Extend the existing service-worker interception test to check that routing preserves explicit cache-control, accept-language and accept request headers. WebKit previously overwrote Cache-Control when routing disabled caching; the production fix already landed in WebKit/WebKit#69997. Keep the existing coverage on frozen WebKit, which predates that fix.

The same test fails with WebKit 26.5 r2336 from Playwright 1.62.1 (no-cache instead of max-age=12345) and passes with current Chromium, Firefox and WebKit. On Linux, the three related spec files pass: 264 passed, 9 skipped. npm run build and npm run flint pass.

Fixes: #41932

_{Prepared by the triage workflow.}

[github-actions]

Test results for "MCP"

1 failed
❌ [webkit] › mcp/sse.spec.ts:196 › sse transport browser lifecycle (persistent) @mcp-ubuntu-latest-webkit

5193 passed, 616 skipped

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Merge workflow run.

[github-actions]

Test results for "tests 1"

1 flaky

⚠️ [chromium-library] › library/video.spec.ts:762 › screencast › VI-030 should work with video+trace `@chromium-playwright-x64-ubuntu24-64-core-node22`

23592 passed, 707 skipped

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Merge workflow run.

[github-actions]

🟢 The CI failure is a confirmed pre-existing flake

Hi, I'm the Playwright bot. I checked the CI reports, the PR changes, and the refreshed test-results database.

Details

The reported failure is not caused by this PR. The MCP report lists one failure; the tests 1 report has no failures.

Pre-existing flake

[webkit] › mcp/sse.spec.ts:196 › sse transport browser lifecycle (persistent) on mcp-ubuntu-latest-webkit — failed here because localStorage.a was undefined, rather than "42", after reopening the persistent browser.

The same test on the same bot failed with the identical assertion before this PR: on main, October 14, SHA 12ade829b4ed, and on #43694, October 28, SHA 38e590a05e16. Excluding this PR, the refreshed database records 724 passing and 12 failing run attempts for this exact test and bot.

This PR only extends a page interception test and its service-worker asset to check request headers. The failing MCP test navigates to the hello-world page, does not load that asset, and exercises unchanged persistent-browser storage behavior.

_{Triaged by the Playwright bot - agent run}