feat(ci): implement test parallelization to reduce CI time

[Copilot]

Parallelize test execution to reduce CI time by 30-50% per Discussion #227.

Changes

Jest Configuration

• Added maxWorkers: '50%' for unit tests (already fast at ~6s for 549 tests)

GitHub Actions Workflow

• Refactored integration tests from 2 hardcoded jobs to matrix strategy with 5 parallel jobs:
  • basic-firewall, robustness, volume-mounts, container-workdir, no-docker
• Set fail-fast: false to complete all tests even on failure
• Each test file runs on isolated runner (required due to Docker network/container conflicts)

strategy:
  fail-fast: false
  matrix:
    include:
      - test-file: basic-firewall.test.ts
        test-name: basic-firewall
      - test-file: robustness.test.ts
        test-name: robustness
      # ... 3 more test files

Documentation

• Added "Test Parallelization Strategy" section to TESTING.md explaining:
  • Unit tests: Jest workers within single runner
  • Integration tests: Matrix strategy across runners (can't use Jest workers due to Docker conflicts)

Original prompt

---

This section details on the original issue you should resolve

<issue_title>[Long-term] Implement test parallelization to reduce CI time</issue_title>
<issue_description>## Context
From CI/CD Pipeline Gap Assessment (Discussion #227)

Description

Parallelize test execution to reduce CI time by 30-50%. This improves developer feedback loops and reduces resource consumption.

Acceptance Criteria

• Analyze current test suite execution time
• Implement parallel test execution (e.g., Jest workers, parallel workflows)
• Achieve 30-50% reduction in CI time
• Ensure test isolation and reliability
• Document parallelization strategy

Estimated Effort

To be determined (quarterly goal)

Related

• Discussion CI/CD Pipeline and Integration Tests - Gap Assessment #227</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes [Long-term] Implement test parallelization to reduce CI time #239

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[github-actions]

✅ Coverage Check Passed

Overall Coverage

Metric	Base	PR	Delta
Lines	77.19%	77.19%	➡️ +0.00%
Statements	77.27%	77.27%	➡️ +0.00%
Functions	77.17%	77.17%	➡️ +0.00%
Branches	69.76%	69.76%	➡️ +0.00%

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Coverage comparison generated by scripts/ci/compare-coverage.ts

[github-actions]

📰 VERDICT: Smoke Copilot has concluded. All systems operational. This is a developing story. 🎤

[github-actions]

🌑 The shadows whisper... Smoke Codex failed. The oracle requires further meditation...

[github-actions]

🎬 THE END — Smoke Claude MISSION: ACCOMPLISHED! The hero saves the day! ✨

[github-actions]

Smoke Test Results

GitHub MCP: #266, #284
Playwright: ✅ Title contains "GitHub"
File Write: ✅ Created test file
Bash Tool: ✅ Verified file contents

Status: PASS

AI generated by Smoke Claude

[github-actions]

Smoke Test Results

Last 2 Merged PRs:

• chore: delete existing firewall tests and migrate smoke tests #229: chore: delete existing firewall tests and migrate smoke tests
• feat(ci): add coverage regression detection #244: feat(ci): add coverage regression detection

Test Results:

• ✅ GitHub MCP: Retrieved PR data successfully
• ❌ Playwright: Blocked by firewall (playwright.azureedge.net not whitelisted)
• ✅ File Writing: Created /tmp/gh-aw/agent/smoke-test-copilot-21092106144.txt
• ✅ Bash Tool: File verification successful

Status: FAIL (Playwright blocked)

cc: @Mossaka @copilot

AI generated by Smoke Copilot