Make test failures concise and directly actionable

Traceability

• Spec ID: test-ci-diagnostics
• Status: Implemented

Intent

Keep the dependency-free node:test suite while making GitHub Actions failures easy to locate. Replace the unbounded default TAP stream with capability groups, compact progress, file-and-line annotations, a job summary, and downloadable JUnit results. Continue removing assertions that merely freeze private HTML/CSS spelling when an executable validator already owns the behavior.

Acceptance Scenarios

• AC-1: CI runs every discovered capability directory, continues after one category fails, and exits non-zero after reporting all failed categories.
• AC-2: Passing tests use compact console output; a failing test emits a GitHub annotation containing its name, repository-relative file, line, and useful error detail.
• AC-3: Every CI matrix job writes one JUnit XML result per capability and uploads the files even when tests fail.
• AC-4: GitHub's step summary lists category status, test-file count, and duration without requiring a third-party test framework or reporter action.
• AC-5: Local npm test remains the direct full-suite command, while npm run test:ci owns CI-only presentation and artifacts.
• AC-6: Remaining report renderer and task-loop projection tests retain data contracts, escaping, accessibility, validator failures, and self-contained artifact boundaries but stop pinning private CSS dimensions and redundant visible-copy spelling.
• AC-7: Tests that repeat an expensive package build or Git fixture setup split reusable mechanics from one representative integration path, while retaining the same portability, replacement, CLI, and analysis contracts.
• AC-8: The categorized runner passes test modules as portable paths relative to its working directory and loads its custom reporter through a file URL, so Windows drive letters are never interpreted as ESM URL schemes.

Non-goals

• Migrating the existing suite to Vitest or Jest without a missing capability that Node 22 cannot provide.
• Publishing test infrastructure in the npm package.
• Adding coverage percentage gates or changing product behavior.
• Editing the concurrently modified Inspector and commit-session test slices.

Plan and Tasks

1. Add test-only CI infrastructure under test/support: discover capability directories, run them sequentially with compact GitHub and JUnit reporters, and aggregate failures.
2. Add focused behavior tests for discovery, annotation escaping, and a real failing child test.
3. Use the CI runner in .github/workflows/ci.yml and upload test-results on every matrix job.
4. Remove renderer and task-loop projection assertions that duplicate validators or freeze layout/copy literals, leaving independent semantic and security oracles intact.
5. Verify focused tests, a successful CI-mode run, the full local suite, package contents, and staged/unstaged boundaries.
6. Use JUnit timings to remove repeated expensive setup from the slowest tests without weakening cross-platform, security, or end-to-end boundaries.
7. Normalize test and reporter module arguments for the Windows Node test runner, and cover the drive-letter projection with a platform-independent behavior test.

Test and Review Evidence

• AC-1..AC-4/AC-8: the CI reporting behavior tests pass 5/5 on local Node 24, including a real failed-first/success-second capability run and a Windows drive-letter path projection. npm run test:ci passes all 8 capability groups and writes 8 JUnit XML files.
• AC-5: npm test passes 1,310/1,310 after adding the Windows runner regression test.
• AC-6: the renderer tests pass 33/33 and the task-loop projection tests pass 84/84. These files contain 60 fewer regex assertions: 48 private HTML/CSS or visible-copy checks and 12 redundant Markdown spelling checks.
• AC-7: JUnit profiling identified three repeated setup costs. The Codex plugin artifact test now performs one full build and tests atomic replacement in isolation; CLI help validates all 53 terminal routes structurally and runs 8 representative guarded owners; both AI census surfaces share one 7-commit repository fixture. On the local Node 24 CI path, the affected slow cases moved from 44.3s to about 19.5s, 16.8s to about 4.2s, and 21.3s per file to about 1.5s respectively.
• Documentation: the focused doc-link graph suite passes 6/6 after regenerating the canonical graph.
• Package: npm run pack:verify passes with 507 npm entries and 529 runtime zip entries. git diff --check is clean.
• Risk: concurrent full-suite runs can exhaust Git fixture resources and create unrelated timeout failures. Run final suites serially and distinguish an environment timeout from an assertion regression.