Revert "feat(test-runner): read last failed tests from --last-failed=<file>"

[Pavel Feldman (pavelfeldman)]

Reverts #42995

[github-actions]

Test results for "tests 1"

5 flaky

⚠️ [chromium-library] › library/video.spec.ts:762 › screencast › should work with video+trace `@chromium-ubuntu-22.04-arm-node20`
⚠️ [chromium-library] › library/video.spec.ts:762 › screencast › should work with video+trace `@chromium-ubuntu-22.04-node24`
⚠️ [chromium-library] › library/browsercontext-page-event.spec.ts:173 › should work with Ctrl-clicking `@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`

52460 passed, 1270 skipped

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Merge workflow run.

[github-actions]

Test results for "MCP"

2 failed
❌ [chrome] › mcp/snapshot-mode.spec.ts:99 › should respect --snapshot-boxes @mcp-macos-latest-chrome
❌ [firefox] › mcp/http.spec.ts:515 › http transport shared context: one idle timer across clients @mcp-windows-latest-firefox

8935 passed, 1489 skipped

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Merge workflow run.

[github-actions]

Hi, I'm the Playwright bot and I triaged the failing CI tests.

🟡 One failure is uncertain

mcp/snapshot-mode.spec.ts:99 › should respect --snapshot-boxes timed out on macOS/Chrome, but this test has no prior failure in 716 recorded runs on that bot. The PR only changes --last-failed handling and does not reach MCP snapshot behavior, so this does not look caused by the PR, but there is not enough evidence to call it a pre-existing flake.

Details

Overall, neither failure exercises code changed by this PR. One is a confirmed pre-existing flake; the other needs a passing rerun or the same failure on an unrelated SHA to clear the PR.

Uncertain

• [chrome] › mcp/snapshot-mode.spec.ts:99 › should respect --snapshot-boxes — timed out after 30 seconds with MCP error -32000: Connection closed on macOS. The test-results history has 716 passes and no failures for this test on macOS/Chrome. Since the PR only reverts test-runner last-failed-file handling, there is no plausible code path from the diff to this MCP failure, but the same-test evidence required to prove a flake is missing.

Pre-existing flake / infra

• [firefox] › mcp/http.spec.ts:515 › http transport shared context: one idle timer across clients — pre-existing flake. The same Firefox test failed on unrelated feat(screencast): style action decorations, keep cursor visible #42758 (run 35252759348) and passed in the other 275 recorded Windows/Firefox runs. This run timed out waiting for the idle client to disconnect; the PR does not touch MCP HTTP sessions, shared contexts, or idle timers.

_{Triaged by the Playwright bot - agent run}