github-actions-test-jobs

Overview

Test workflows are YAML files in .github/workflows/ that run jobs on trigger events (gha). This skill sets up the idiomatic patterns - matrix builds, sharding, service containers, JUnit reporting, trigger filtering, concurrency, and secrets. Start with the minimal pattern in Step 1.

When to use

• Project on GitHub.
• Need to set up test CI for a new repo.
• Existing GitHub Actions workflows need standardization.

How to use

1. Add .github/workflows/test.yml triggered on pull_request and push to main; check out the repo and set up the runtime (Step 1).
2. Install dependencies and run the suite (npm ci then npm test).
3. Add a build matrix over OS and runtime versions with fail-fast: false for multi-target signal (Step 2), and shard large suites across parallel jobs (Step 3).
4. Wire any service containers the tests need and emit JUnit XML, uploading it with if: always() - references/services-and-reporting.md.
5. Filter triggers by path and add schedule / workflow_dispatch (Step 7); add a concurrency group so superseded pushes cancel (Step 8).
6. Move tokens into secrets.* and reference them from step env (Step 9).
7. Verify the workflow runs (see Verify below), then review the anti-patterns table before merging.

Step 1 - Basic test workflow

# .github/workflows/test.yml
name: test

on:
  pull_request:
  push:
    branches: [main]

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v5
      - uses: actions/setup-node@v4
        with: { node-version: '22' }
      - run: npm ci
      - run: npm test

The minimal pattern: trigger on PR + push-to-main, install deps, run tests.

Step 2 - Matrix builds

jobs:
  test:
    runs-on: ${{ matrix.os }}
    strategy:
      fail-fast: false
      matrix:
        os: [ubuntu-latest, macos-latest, windows-latest]
        node: [20, 22]
    steps:
      - uses: actions/checkout@v5
      - uses: actions/setup-node@v4
        with: { node-version: ${{ matrix.node }} }
      - run: npm ci
      - run: npm test

fail-fast: false ensures one matrix failure doesn't cancel others. Matrix size is OS × Node = 3 × 2 = 6 jobs.

Runner pinning, per-language runtime matrices (Node / Python / Java / .NET), OS-specific quirks (path separators, line endings, case sensitivity, shells), per-OS conditional steps and tests, and the tiered cost-management cadence are in references/os-matrix.md.

Step 3 - Sharding for parallel execution

For large suites:

jobs:
  test:
    strategy:
      matrix:
        shard: [1, 2, 3, 4]
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v5
      - run: npx jest --shard=${{ matrix.shard }}/4

4 parallel jobs, each running 1/4 of the test suite. Faster than serial execution; cost-equivalent (same total CPU-time).

Service containers and reporting

Wiring the service containers the tests depend on (PostgreSQL, Redis) and publishing JUnit XML as artifacts plus PR-check summaries are in references/services-and-reporting.md.

Step 6 - Retry policy

GitHub Actions doesn't ship native test-retry; use the framework's retry mechanism (e.g., Playwright's retries config) or a wrapper action:

- uses: nick-fields/retry@v3
  with:
    timeout_minutes: 10
    max_attempts: 2
    command: npm test

Use sparingly - retries hide flake. Prefer flaky-test-quarantine (in the qa-flake-triage plugin).

Step 7 - Per-trigger filtering

on:
  pull_request:
    paths:
      - 'src/**'
      - 'tests/**'
      - 'package.json'

  push:
    branches: [main]
    paths-ignore:
      - 'docs/**'
      - '*.md'

  schedule:
    - cron: '0 4 * * *'   # daily 4am UTC

  workflow_dispatch:        # manual trigger
    inputs:
      target_browser:
        description: 'Browser to test'
        type: choice
        options: [chrome, firefox, safari]
        default: chrome

Path filters skip workflows when only docs change - saves CI budget.

Step 8 - Concurrency control

concurrency:
  group: ${{ github.workflow }}-${{ github.head_ref || github.ref }}
  cancel-in-progress: true

When a PR receives multiple pushes, the older runs cancel - saves CI cost on superseded commits.

Step 9 - Secrets + env

env:
  CI: true

steps:
  - run: npm test
    env:
      NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
      DATABASE_URL: ${{ secrets.TEST_DATABASE_URL }}

Secrets configured in repo settings; never committed.

Verify before merge

Run the workflow once before merging - push the branch or trigger it manually via workflow_dispatch (or dry-run locally with act).

Verify: the matrix expands into the expected job count (e.g. OS × Node = 3 × 2 = 6 jobs) and each job uploads its JUnit artifact. If a job fails on a missing secret, confirm NPM_TOKEN / TEST_DATABASE_URL exist under repo Settings -> Secrets and variables -> Actions, add any that are missing, and re-run the job.

Worked example

A Node service needs PR tests on Linux + macOS, plus a nightly full run against PostgreSQL.

1. test.yml triggers on pull_request and push to main, with schedule: cron '0 4 * * *' for the nightly run.
2. The test job runs a matrix of os: [ubuntu-latest, macos-latest] × node: [20, 22] with fail-fast: false - 4 jobs, and no target cancels another.
3. A separate integration job (Linux only) declares a postgres:15 service with a pg_isready healthcheck and passes DATABASE_URL into npm test.
4. Tests emit test-results/junit.xml; actions/upload-artifact@v4 with if: always() keeps the report even when tests fail, and dorny/test-reporter@v1 renders it in the PR check summary.
5. A concurrency group keyed on the ref cancels superseded runs, so rapid pushes don't pile up billable minutes.

Result: PR authors get fast cross-platform signal, the nightly catches DB-integration regressions, and failed runs still surface their JUnit report.

Anti-patterns

Anti-pattern	Why it fails	Fix
fail-fast: true on matrix	First failure cancels all; lose multi-target signal.	fail-fast: false (Step 2).
No concurrency group	PRs with rapid pushes pile CI runs.	Add concurrency cancel (Step 8).
if: always() everywhere	Some steps shouldn't run on failure (deploy).	Selective if: always() for upload steps only (services-and-reporting).
Hardcoded secrets in YAML	Secret leak; revocation needed.	secrets.X references (Step 9).
Massive single workflow file	Hard to navigate; merge conflicts.	Split per concern (test.yml, deploy.yml, lint.yml).
Missing actions/checkout step	Job can't access repo files.	First step always (Step 1).

Limitations

• Runner cost. macOS / Windows runners 5x-10x more expensive than Linux (after free quota). Budget accordingly.
• Per-job 6h timeout. Long jobs need splitting.
• Service containers Linux-only. macOS / Windows runners don't support services: block.
• JUnit reporting requires a third-party action. No native.

References

• gha - GitHub Actions workflow basics: events + jobs + steps; YAML in .github/workflows/.
• references/os-matrix.md - OS / runtime matrix depth + per-OS quirks.
• references/services-and-reporting.md - service container + JUnit reporting recipes.
• gitlab-ci-test-jobs, jenkinsfile-test-stages - per-platform alternatives.
• ci-test-job-conventions - cross-CI conventions; CircleCI patterns live in its references/circleci.md.
• junit-xml-analysis - downstream JUnit XML parser.
• flaky-test-quarantine - preferred over retries.