test: per-directory coverage + E2E cleanup hardening (Days 5-6)

[tejaskash]

Summary

Two days of test infrastructure work bundled together since they're orthogonal but small.

Day 5 — Per-directory coverage thresholds

• New scripts/check-coverage.mjs enforces per-directory line coverage thresholds (ratchet values ~5% below current coverage; target values documented inline)
• PR-changed-line coverage check (≥50%) with per-file breakdown
• Switched davelosert/vitest-coverage-report-action to file-coverage-mode: changes so PR comments highlight uncovered new lines
• Ratchet thresholds: schema 78%, operations 52%, lib 82%, aws 40%, tui/hooks 14%, tui/components 68%, commands 46%

Day 6 — E2E cleanup hardening + sweeper spec

• teardownE2EProject() retries deploy up to 3× (15s backoff) and throws on failure instead of swallowing silently. Stops silent AWS resource leaks.
• CDK stacks now tagged with Environment=e2e-test / CreatedAt / CreatedBy when AGENTCORE_E2E_TEST=1 is set (opt-in, user projects unaffected)
• cleanupStaleCredentialProviders window shrunk from 30min → 5min — catches orphans faster
• Cognito cleanup in byo-custom-jwt.test.ts retries 3× with 5s delay instead of swallowing errors
• New docs/test-resource-sweeper-spec.md for the infra team to implement a scheduled sweeper

Test plan

• node scripts/check-coverage.mjs passes against current coverage locally
• Coverage job in CI runs and posts per-directory table on this PR
• Intentionally lower a threshold → CI fails (verify the gate works)
• Typecheck passes on all packages

[agentcore-cli-automation]

Reducing cleanupStaleCredentialProviders to 5 minutes looks risky for the full E2E suite.

cleanupStaleCredentialProviders() is called in beforeAll of every E2E test file, and it deletes any E2e* provider older than maxAgeMs. In e2e-tests-full.yml, the suite runs as a 6-shard × 2-source matrix (12 parallel jobs) against one AWS account, and within a shard vitest runs multiple test files in parallel — so many tests' credential providers live concurrently in the same namespace.

With a 5-minute window, a test whose deploy takes >5 min (container builds have a 900s/15-min timeout, and regular deploys routinely go past 5 min) can have its active credential provider deleted by another test file's beforeAll that fires later. Net effect: flakes caused by the cleanup itself.

A few options, pick whichever fits best:

1. Keep the window generous (e.g. 20–30 min) — the stated goal is catching crash-orphaned providers, and those sit around for hours until the sweeper runs, so 5 min buys very little.
2. Instead of age-based cleanup, track provider names created by the current run (e.g. via a file or env-scoped prefix) and only delete foreign/orphaned names.
3. Gate the 5-min value on something like maxAgeMs = parseInt(process.env.E2E_STALE_CRED_MAX_AGE_MS ?? '', 10) || 30*60*1000 so the scheduled sweeper can use a tight window but normal CI runs stay safe.

[agentcore-cli-automation]

teardownE2EProject throwing on failure now leaks the test temp directory.

In createE2ESuite's afterAll (e2e-helper.ts:98–103):

afterAll(async () => {
  if (projectPath && hasAws) {
    await teardownE2EProject(projectPath, agentName, cfg.modelProvider);
  }
  if (testDir) await rm(testDir, { recursive: true, force: true, maxRetries: 3, retryDelay: 1000 });
}, 600000);

Previously teardownE2EProject swallowed errors, so the rm(testDir, ...) always ran. After this PR it throws, which means every teardown failure now also leaks testDir under os.tmpdir() on the runner. On top of that, any AWS cleanup the caller (evals-lifecycle, archive-lifecycle, ab-test-*, config-bundle-eval-rec, etc.) does after the teardownE2EProject call in its own afterAll is skipped too.

Options:

1. Wrap the teardown call in the afterAll in a try { ... } finally { await rm(testDir, ...); } (and similarly in the other suites that call it directly).
2. In teardownE2EProject, record the failure (console.error + maybe write a marker file) instead of throwing, and fail the run via a different mechanism (e.g. a top-level afterAll that asserts no recorded failures).
3. Keep the throw but restructure each caller's afterAll so cleanup steps that must always run are in finally blocks.

[agentcore-cli-automation]

The PR-changed-line gate silently ignores new/changed .tsx files, which is a big hole in the coverage gate.

In scripts/check-coverage.mjs:

const coveredSet = coveredLinesByFile[file];
if (!coveredSet) continue;

coveredLinesByFile is built from coverage/coverage-final.json, and vitest.config.ts sets coverage.include: ['src/**/*.ts'] (no .tsx). That glob doesn't match .tsx, so TUI files like src/cli/tui/**/*.tsx never appear in the coverage JSON → coveredSet is undefined → those lines are continued past, contributing 0 to both numerator and denominator.

Meanwhile the git-diff in the same script explicitly includes src/**/*.tsx:

`git diff ${baseSha}...${headSha} --unified=0 --diff-filter=AM -- 'src/**/*.ts' 'src/**/*.tsx'`

So a PR that adds a brand-new .tsx file full of untested code will show 0 changed lines counted and pass the 50% threshold cleanly. Same for any edit to existing .tsx files — they're invisible to the gate. Given src/cli/tui/components/ has its own 68% ratchet, this is almost certainly unintentional.

Options:

1. Extend coverage.include in vitest.config.ts to ['src/**/*.ts', 'src/**/*.tsx'] so .tsx files show up in the report (preferred — also fixes the per-directory gate for TUI components).
2. In check-coverage.mjs, treat coveredSet === undefined for a production file as 0% covered (i.e. count all changed lines as uncovered) instead of skipping.
3. At minimum, drop src/**/*.tsx from the git diff pathspec and document that .tsx isn't gated, so the hole is explicit rather than silent.

[tejaskash]

Addressed — reverted the default to 30 min and added an opt-in E2E_STALE_CRED_MAX_AGE_MS env var so the scheduled sweeper can still use a tight window without risking normal CI.

[tejaskash]

Addressed — wrapped the teardownE2EProject call in try/finally across createE2ESuite + all 5 standalone callers (ab-test-target-based, ab-test-config-bundle, archive-lifecycle, config-bundle-eval-rec, evals-lifecycle) so testDir cleanup always runs.

[tejaskash]

Addressed — extended vitest.config.ts coverage include to src/**/*.tsx (and excluded *.test.tsx), plus hardened check-coverage.mjs to treat a changed production file missing from coverage as 0% covered instead of skipping. Adjusted the src/cli/commands/ ratchet from 46% → 34% to reflect the new denominator (3424 → 4553 lines with .tsx included).

[github-actions]

Coverage Report

Status	Category	Percentage	Covered / Total
🔵	Lines	33.39%	9015 / 26999
🔵	Statements	32.76%	9573 / 29214
🔵	Functions	29.2%	1553 / 5318
🔵	Branches	28.38%	5808 / 20465

File Coverage

No changed files found.

Generated in workflow #2471 for commit 9c0156f by the Vitest Coverage Report Action

[github-actions]

Test Coverage Report

Overall

Metric	Coverage
Statements	32.76%
Branches	28.38%
Functions	29.2%
Lines	33.39%

Per-Directory Line Coverage

Directory	Coverage	Ratchet	Target	Status
src/schema/	83.0% (322/388)	78%	85%	PASS
src/cli/operations/	57.0% (2457/4314)	52%	65%	PASS
src/lib/	87.1% (695/798)	82%	85%	PASS
src/cli/aws/	45.6% (579/1270)	40%	60%	PASS
src/cli/tui/hooks/	18.8% (280/1489)	14%	55%	PASS
src/cli/tui/components/	73.9% (886/1199)	68%	75%	PASS
src/cli/commands/	39.0% (1781/4561)	34%	60%	PASS

PR Changed Lines

100.0% (0/0) — threshold 50% — PASS