test: response.body() for content-encoding:identity

[Dmitry Gozman (dgozman)]

Closes #42501.

[github-actions]

Test results for "tests 1"

10 flaky

⚠️ [chromium-library] › library/browsercontext-page-event.spec.ts:160 › should work with Shift-clicking `@chromium-ubuntu-22.04-arm-node20`
⚠️ [chromium-library] › library/popup.spec.ts:260 › should not throw when click closes popup `@chromium-ubuntu-22.04-node24`
⚠️ [chromium-library] › library/chromium/chromium.spec.ts:179 › serviceWorker(), and fromServiceWorker() work `@chromium-ubuntu-22.04-node20`
⚠️ [chromium-library] › library/video.spec.ts:495 › screencast › should capture static page in persistent context Radoslav Kirilov (@smoke) `@chromium-ubuntu-22.04-node20`
⚠️ [chromium-library] › library/chromium/chromium.spec.ts:436 › should produce network events, routing, and annotations for Service Worker (advanced) `@chromium-ubuntu-22.04-node22`
⚠️ [chromium-library] › library/video.spec.ts:495 › screencast › should capture static page in persistent context Radoslav Kirilov (@smoke) `@chromium-ubuntu-22.04-node22`
⚠️ [firefox-library] › library/browsercontext-cookies-third-party.spec.ts:257 › third party 'Partitioned;' cookies `@firefox-ubuntu-22.04-node20`
⚠️ [firefox-library] › library/browsercontext-cookies-third-party.spec.ts:470 › top level 'Partitioned;' cookie and same origin iframe `@firefox-ubuntu-22.04-node20`
⚠️ [firefox-page] › page/page-event-request.spec.ts:181 › should return response body when Cross-Origin-Opener-Policy is set `@firefox-ubuntu-22.04-node20`
⚠️ [firefox-page] › page/page-goto.spec.ts:90 › should work with Cross-Origin-Opener-Policy `@firefox-ubuntu-22.04-node20`

51330 passed, 1247 skipped

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Merge workflow run.

[github-actions]

Test results for "MCP"

1 failed
❌ [firefox] › mcp/cli-core.spec.ts:140 › uncheck @mcp-windows-latest-firefox

8300 passed, 1371 skipped

---

Merge workflow run.

[github-actions]

Hi, I'm the Playwright bot and I took a first look at the CI failures here.

🟢 The one failure is a pre-existing flake — this PR is clear

The only real failure is [firefox] › mcp/cli-core.spec.ts:140 › uncheck on mcp-windows-latest-firefox. It's a known Firefox/Windows flake, unrelated to this test-only PR (which adds a response.text() case for Content-Encoding: identity). The "tests 1" run had no failures — 10 flaky only.

Details

Overall: this PR adds a single page-network-response test and touches nothing in the MCP CLI or the browser code paths that uncheck exercises. Nothing in the diff can reach the failing test.

Pre-existing flake / infra

• [firefox] › mcp/cli-core.spec.ts:140 › uncheck (@mcp-windows-latest-firefox) — confirmed flake. Across the test-results DB this test flips verdict: failed 6 of 712 runs (~0.8%), passed the other 706, and every failure is on mcp-windows-latest-firefox. Those 6 failures are on SHAs this PR can't be responsible for — a push to main (run 30585190799) and five unrelated PRs (feat(test-runner): annotate serial suites for custom sharding #42164, test: race between disabling interception and network request in chromium #42254, feat(tracing): allow configuring the screenshots size #42283, fix(cli): stop daemon when socket disappears #42454, fix(video): embed recording start time in WebM metadata #42478). It has never failed on this PR's branch.

Flaky (not failures, no triage needed)

• The "tests 1" run reported 10 flaky tests (all passed on retry) across chromium/firefox library and page suites — service worker, video screencast, partitioned cookies, COOP, etc. None overlap the diff.

_{Triaged by the Playwright bot - agent run}