Fix flaky CI tests: live-clock polling, GitManager timeouts, web test budget

[t3dotgg]

Summary

Audited the last ~50 failed CI runs and fixed the recurring cross-branch flakes (as opposed to genuine PR-branch failures):

• CursorAdapter.test.ts — "cancels pending ACP approvals…" (7+ CI failures across unrelated branches). The test polled the mock agent's request log with bare Effect.yieldNow loops, which yield zero wall-clock time under it.effect's TestClock. The mock agent is a separate OS process, so its session/cancel log append routinely landed after the ~40 microtask hops and the assertion read stale data. A standalone repro of the old helper missed a write arriving just 5ms late, 3/3 times.
• ProviderRegistry.test.ts — "re-probes when settings change the codex binaryPath" (documented known flake). Same mechanism: the re-probe spawns a real child process whose ENOENT arrives on the live event loop, but the poll loop only did TestClock.adjust + yieldNow.
• GitManager.test.ts — cross-repo PR tests timing out at 12s (documented known flake). Six tests carried 12s/20s per-test timeouts left over from when the suite default was Vitest's 5s. The server suite now sets a 120s budget precisely because these git-subprocess-heavy tests crawl on loaded CI hosts — the stale overrides only shrank the budget. Removed them.
• MessagesTimeline.test.tsx — "anchors a sent attachment message…" timed out at exactly the web suite's 15s budget under a full-monorepo parallel test run. Raised apps/web test/hook timeouts to match the root config's 60s.

Fix

New shared helper apps/server/src/provider/testUtils/pollUntil.ts: polls an effect until a predicate matches, sleeping on the live clock via TestClock.withLive between attempts (so child processes and libuv make progress while the test stays on the virtual clock), and dies loudly with the last polled value on timeout instead of silently returning stale data. Both flaky server test files now use it for every cross-process wait. readJsonLines also tolerates a partially written trailing line while the child is mid-append.

Updated .cursor/rules/cursor-cloud.mdc known-flaky notes to describe the fixes and point future polling waits at pollUntil.

Testing

• ✅ vp run typecheck
• ✅ vp check --fix (formatter-clean, 0 errors)
• ✅ vp run test in apps/server — full suite, 160 files / 1397 tests passed
• ✅ vp test src/components/chat/MessagesTimeline.test.tsx in apps/web
• ✅ Stress test: previously flaky CursorAdapter cancel test ran 8×, and ProviderRegistry re-probe test 5×, under 6 concurrent CPU busy-loops on a 4-core VM — all passed
• ✅ Standalone repro confirmed the old waitForJsonLogMatch misses a 5ms-late cross-process write (3/3 runs), validating the root cause

  

Note

Fix flaky CI tests by replacing manual polling loops with live-clock pollUntil utility

• Adds pollUntil, a reusable test utility that polls an Effect on the live clock (default 10s timeout, 25ms interval) until a predicate matches, using TestClock.withLive to avoid interference with it.effect's test clock.
• Updates CursorAdapter.test.ts and ProviderRegistry.test.ts to replace manual Effect.yieldNow loops with pollUntil, fixing races on out-of-process child process and file I/O timing.
• Fixes partial JSON line errors in readJsonLines by silently skipping lines that fail to parse, handling mid-write appends from separate processes.
• Removes explicit per-test timeout overrides in GitManager.test.ts, deferring to the framework default.
• Increases Vitest hookTimeout and testTimeout from 15s to 60s in apps/web/vite.config.ts to align with root config budget under CI contention.

📊 Macroscope summarized c660f28. 3 files reviewed, 0 issues evaluated, 0 issues filtered, 0 comments posted

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