Get Started with CI/CD Pipelines: Your First Concrete Step Today

pip install pytest pytest-cov

# Run tests with coverage
pytest --cov=mon_module --cov-report=term --cov-report=html

# Console output:
# Name            Stmts   Miss  Cover
# -------------------------------------
# mon_module.py     50      5    90%
# -------------------------------------
# TOTAL             50      5    90%

# Interactive HTML report in htmlcov/index.html

[tool.pytest.ini_options]
addopts = "--cov=src --cov-report=term-missing --cov-report=xml --cov-fail-under=80"

[tool.coverage.run]
source = ["src"]
omit = [
    "*/tests/*",
    "*/migrations/*",
    "*/__init__.py"
]

[tool.coverage.report]
exclude_lines = [
    "pragma: no cover",
    "raise NotImplementedError",
    "if __name__ == .__main__.:",
]
fail_under = 80
show_missing = true

npm install --save-dev jest

# package.json
{
  "scripts": {
    "test": "jest",
    "test:coverage": "jest --coverage"
  },
  "jest": {
    "collectCoverageFrom": [
      "src/**/*.{js,ts}",
      "!src/**/*.d.ts",
      "!src/index.ts"
    ],
    "coverageThreshold": {
      "global": {
        "branches": 75,
        "functions": 80,
        "lines": 80,
        "statements": 80
      }
    },
    "coverageReporters": ["text", "lcov", "html", "cobertura"]
  }
}

# Run
npm run test:coverage

# If threshold not met:
# Jest: "global" coverage threshold for lines (80%) not met: 73.5%
# → Build FAILS

<!-- pom.xml -->
<plugin>
  <groupId>org.jacoco</groupId>
  <artifactId>jacoco-maven-plugin</artifactId>
  <version>0.8.11</version>
  <executions>
    <execution>
      <goals><goal>prepare-agent</goal></goals>
    </execution>
    <execution>
      <id>report</id>
      <phase>test</phase>
      <goals><goal>report</goal></goals>
    </execution>
    <execution>
      <id>jacoco-check</id>
      <goals><goal>check</goal></goals>
      <configuration>
        <rules>
          <rule>
            <element>BUNDLE</element>
            <limits>
              <limit>
                <counter>LINE</counter>
                <value>COVEREDRATIO</value>
                <minimum>0.80</minimum>
              </limit>
            </limits>
          </rule>
        </rules>
      </configuration>
    </execution>
  </executions>
</plugin>

mvn clean test
# Report in target/site/jacoco/index.html

name: CI with Coverage

on: [push, pull_request]

jobs:
  test:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      
      - name: Setup Python
        uses: actions/setup-python@v5
        with:
          python-version: '3.12'
      
      - name: Install
        run: pip install -e ".[dev]"
      
      - name: Tests + coverage
        run: pytest --cov --cov-report=xml --cov-report=term --cov-fail-under=80
      
      - name: Upload coverage to Codecov
        uses: codecov/codecov-action@v4
        with:
          file: ./coverage.xml
          token: ${{ secrets.CODECOV_TOKEN }}
          fail_ci_if_error: true

coverage:
  status:
    project:
      default:
        target: 80%
        threshold: 1%
    patch:
      default:
        target: 90%
        threshold: 5%

comment:
  layout: "header, diff, flags, files"
  behavior: default
  require_changes: false

ignore:
  - "tests/**"
  - "**/__init__.py"
  - "migrations/**"

- name: Build wheel
  run: python -m build

- name: Upload wheel as artifact
  uses: actions/upload-artifact@v4
  with:
    name: python-wheel
    path: dist/*.whl
    retention-days: 30

deploy:
  needs: build
  runs-on: ubuntu-latest
  steps:
    - name: Download wheel
      uses: actions/download-artifact@v4
      with:
        name: python-wheel
        path: ./dist
    
    - name: Install
      run: pip install dist/*.whl

- name: Login Docker Hub
  uses: docker/login-action@v3
  with:
    username: ${{ secrets.DOCKERHUB_USERNAME }}
    password: ${{ secrets.DOCKERHUB_TOKEN }}

- name: Build and push
  uses: docker/build-push-action@v5
  with:
    context: .
    push: true
    tags: |
      myuser/myapp:latest
      myuser/myapp:${{ github.sha }}
      myuser/myapp:${{ github.ref_name }}
    platforms: linux/amd64,linux/arm64
    cache-from: type=gha
    cache-to: type=gha,mode=max

- name: Login to GHCR
  uses: docker/login-action@v3
  with:
    registry: ghcr.io
    username: ${{ github.actor }}
    password: ${{ secrets.GITHUB_TOKEN }}

- name: Build and push
  uses: docker/build-push-action@v5
  with:
    push: true
    tags: |
      ghcr.io/${{ github.repository }}:latest
      ghcr.io/${{ github.repository }}:${{ github.sha }}

- name: Configure AWS credentials
  uses: aws-actions/configure-aws-credentials@v4
  with:
    role-to-assume: arn:aws:iam::123456789012:role/github-actions-ecr
    aws-region: eu-west-3

- name: Login to ECR
  id: ecr
  uses: aws-actions/amazon-ecr-login@v2

- name: Build and push
  uses: docker/build-push-action@v5
  with:
    push: true
    tags: |
      ${{ steps.ecr.outputs.registry }}/myapp:latest
      ${{ steps.ecr.outputs.registry }}/myapp:${{ github.sha }}

- name: Generate tags
  id: meta
  uses: docker/metadata-action@v5
  with:
    images: myuser/myapp
    tags: |
      type=ref,event=branch
      type=ref,event=pr
      type=semver,pattern={{version}}
      type=semver,pattern={{major}}.{{minor}}
      type=semver,pattern={{major}}
      type=sha,prefix=sha-,format=short
      type=raw,value=latest,enable={{is_default_branch}}

# Automatic output according to context:
# - on main: latest, sha-abc1234, main
# - on tag v1.2.3: 1.2.3, 1.2, 1, sha-abc1234
# - on PR #42: pr-42, sha-abc1234