# Running Tests in CI — JUnit 5 & Mockito

Source: https://www.skillbyai.com/en/java-testing/p-ci

> Organise unit and integration tests in builds and keep the pipeline fast and trustworthy.

## Tests that run on every change

Tests protect you only if they run automatically. In CI, run the **fast unit tests** on every push and pull request, and **integration tests** (Testcontainers, Spring context) in the same pipeline or a parallel job. With Maven, **Surefire** runs `*Test` classes during `test`, and **Failsafe** runs `*IT` classes during `integration-test` and `verify`, ensuring cleanup steps still run if integration tests fail. With Gradle, define a separate source set or task for integration tests. Publish **JUnit XML reports** so the CI system shows failures, durations and trends; publish coverage reports too. Keep the pipeline fast: parallelise test execution and CI jobs, cache dependencies, reuse containers, and move slow end-to-end suites to a separate stage. Treat **flaky tests** as bugs: track them, quarantine with a ticket if necessary, and fix them quickly. Make a **red build stop the line**: nobody merges on top of failing tests.

## A GitHub Actions workflow for a Maven project

Unit and integration tests, with reports uploaded for every run.

```yaml
name: build
on: [push, pull_request]

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-java@v4
        with:
          distribution: temurin
          java-version: '21'
          cache: maven
      - name: Unit and integration tests
        run: ./mvnw -B verify          # surefire (*Test) then failsafe (*IT); Docker is available on this runner
      - name: Upload test reports
        if: always()
        uses: actions/upload-artifact@v4
        with:
          name: test-reports
          path: |
            target/surefire-reports
            target/failsafe-reports
            target/site/jacoco
```

## Quality checks on an assembly line

CI tests are the inspection stations on an assembly line: quick checks at every step catch defects immediately, and a full inspection before shipping catches what slipped through. Stopping the line when a check fails is cheaper than recalling cars later.

**Quiz:** In a Maven build, which plugin conventionally runs integration test classes named *IT?

- [ ] Surefire
- [x] Failsafe
- [ ] JaCoCo
- [ ] Shade

*Answer:* Failsafe. Failsafe runs integration tests in the integration-test and verify phases.