CI Integration

Run Delta Coverage in your CI pipeline to enforce coverage on every pull request.

GitHub Actions

Gradle PluginCLI

name: Build

on:
  pull_request:
    branches: [main]

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0  # Required for git diff

      - uses: actions/setup-java@v4
        with:
          java-version: '17'
          distribution: 'temurin'

      - name: Run tests with coverage
        run: ./gradlew test deltaCoverage

name: Build

on:
  pull_request:
    branches: [main]

jobs:
  coverage:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - uses: actions/setup-java@v4
        with:
          java-version: '17'
          distribution: 'temurin'

      - name: Build and test
        run: ./gradlew build

      - name: Generate diff
        run: git diff origin/${{ github.base_ref }}...HEAD > changes.diff

      - name: Download Delta Coverage CLI
        run: |
          curl -L -o delta-coverage-cli.jar \
            https://repo1.maven.org/maven2/io/github/gw-kit/delta-coverage-cli/3.6.0/delta-coverage-cli-3.6.0.jar

      - name: Run Delta Coverage
        run: |
          java -jar delta-coverage-cli.jar \
            --engine JACOCO \
            --diff-file changes.diff \
            --coverage-binary 'build/**/jacoco/*.exec' \
            --classes 'build/classes/**/main' \
            --sources src/main/java \
            --html --console \
            --min-coverage 0.8 \
            --fail-on-violation

      - name: Upload coverage report
        uses: actions/upload-artifact@v4
        if: always()
        with:
          name: delta-coverage-report
          path: build/reports/delta-coverage

fetch-depth: 0

Without full git history, the plugin cannot compute the diff against the base branch.

With PR Comments

Use delta-coverage-action to post coverage reports as PR comments:

- name: Run tests with coverage
  run: ./gradlew test deltaCoverage
  continue-on-error: true

- name: Post coverage comment
  uses: gw-kit/delta-coverage-action@v1
  with:
    report-path: build/reports/coverage-reports/delta-coverage/test/report.md

See PR Comments for detailed setup.

GitLab CI

Gradle PluginCLI

stages:
  - test

test:
  stage: test
  image: eclipse-temurin:17
  script:
    - ./gradlew test deltaCoverage
  artifacts:
    paths:
      - build/reports/coverage-reports/
    reports:
      coverage_report:
        coverage_format: cobertura
        path: build/reports/coverage-reports/delta-coverage/test/report.xml

stages:
  - test

delta-coverage:
  stage: test
  image: eclipse-temurin:17-jdk
  script:
    - ./gradlew build
    - git diff origin/main...HEAD > changes.diff
    - |
      curl -L -o delta-coverage-cli.jar \
        https://repo1.maven.org/maven2/io/github/gw-kit/delta-coverage-cli/3.6.0/delta-coverage-cli-3.6.0.jar
    - |
      java -jar delta-coverage-cli.jar \
        --engine JACOCO \
        --diff-file changes.diff \
        --coverage-binary 'build/**/jacoco/*.exec' \
        --classes 'build/classes/**/main' \
        --sources src/main/java \
        --html --console \
        --min-coverage 0.8 \
        --fail-on-violation
  artifacts:
    when: always
    paths:
      - build/reports/delta-coverage
    expire_in: 1 week

GitLab Coverage Parsing

Add to your job:

coverage: '/Total.*?(\d+(?:\.\d+)?)%/'

Jenkins

Gradle PluginCLI

Declarative Pipeline

pipeline {
    agent any

    stages {
        stage('Test') {
            steps {
                sh './gradlew test deltaCoverage'
            }
        }
    }

    post {
        always {
            publishHTML(target: [
                reportDir: 'build/reports/coverage-reports/delta-coverage/test/html',
                reportFiles: 'index.html',
                reportName: 'Delta Coverage'
            ])
        }
    }
}

Declarative Pipeline

pipeline {
    agent any

    stages {
        stage('Build') {
            steps {
                sh './gradlew build'
            }
        }
        stage('Delta Coverage') {
            steps {
                sh 'git diff origin/main...HEAD > changes.diff'
                sh '''
                    curl -L -o delta-coverage-cli.jar \
                      https://repo1.maven.org/maven2/io/github/gw-kit/delta-coverage-cli/3.6.0/delta-coverage-cli-3.6.0.jar
                '''
                sh '''
                    java -jar delta-coverage-cli.jar \
                      --engine JACOCO \
                      --diff-file changes.diff \
                      --coverage-binary 'build/**/jacoco/*.exec' \
                      --classes 'build/classes/**/main' \
                      --sources src/main/java \
                      --html --console \
                      --fail-on-violation
                '''
            }
        }
    }

    post {
        always {
            publishHTML(target: [
                reportDir: 'build/reports/delta-coverage',
                reportFiles: 'html/index.html',
                reportName: 'Delta Coverage'
            ])
        }
    }
}

CircleCI

Gradle PluginCLI

version: 2.1

jobs:
  build:
    docker:
      - image: cimg/openjdk:17.0
    steps:
      - checkout
      - run:
          name: Run tests with coverage
          command: ./gradlew test deltaCoverage
      - store_artifacts:
          path: build/reports/coverage-reports
          destination: coverage-reports

version: 2.1

jobs:
  build:
    docker:
      - image: cimg/openjdk:17.0
    steps:
      - checkout
      - run:
          name: Build and test
          command: ./gradlew build
      - run:
          name: Generate diff
          command: git diff origin/main...HEAD > changes.diff
      - run:
          name: Run Delta Coverage
          command: |
            curl -L -o delta-coverage-cli.jar \
              https://repo1.maven.org/maven2/io/github/gw-kit/delta-coverage-cli/3.6.0/delta-coverage-cli-3.6.0.jar
            java -jar delta-coverage-cli.jar \
              --engine JACOCO \
              --diff-file changes.diff \
              --coverage-binary 'build/**/jacoco/*.exec' \
              --classes 'build/classes/**/main' \
              --sources src/main/java \
              --html --console \
              --fail-on-violation
      - store_artifacts:
          path: build/reports/delta-coverage
          destination: delta-coverage-report

Azure Pipelines

Gradle PluginCLI

trigger:
  - main

pool:
  vmImage: 'ubuntu-latest'

steps:
  - task: Gradle@3
    inputs:
      gradleWrapperFile: 'gradlew'
      tasks: 'test deltaCoverage'
      javaHomeOption: 'JDKVersion'
      jdkVersionOption: '17'

  - task: PublishCodeCoverageResults@2
    inputs:
      codeCoverageTool: 'JaCoCo'
      summaryFileLocation: 'build/reports/coverage-reports/delta-coverage/test/report.xml'
      reportDirectory: 'build/reports/coverage-reports/delta-coverage/test/html'

trigger:
  - main

pool:
  vmImage: 'ubuntu-latest'

steps:
  - task: JavaToolInstaller@0
    inputs:
      versionSpec: '17'
      jdkArchitectureOption: 'x64'
      jdkSourceOption: 'PreInstalled'

  - script: ./gradlew build
    displayName: 'Build and test'

  - script: git diff origin/main...HEAD > changes.diff
    displayName: 'Generate diff'

  - script: |
      curl -L -o delta-coverage-cli.jar \
        https://repo1.maven.org/maven2/io/github/gw-kit/delta-coverage-cli/3.6.0/delta-coverage-cli-3.6.0.jar
      java -jar delta-coverage-cli.jar \
        --engine JACOCO \
        --diff-file changes.diff \
        --coverage-binary '$(Build.SourcesDirectory)/build/**/jacoco/*.exec' \
        --classes '$(Build.SourcesDirectory)/build/classes/**/main' \
        --sources $(Build.SourcesDirectory)/src/main/java \
        --report-dir $(Build.ArtifactStagingDirectory)/delta-coverage \
        --html --console \
        --fail-on-violation
    displayName: 'Run Delta Coverage'

  - task: PublishBuildArtifacts@1
    condition: always()
    inputs:
      pathToPublish: '$(Build.ArtifactStagingDirectory)/delta-coverage'
      artifactName: 'delta-coverage-report'

Configuration for CI

Compare with PR Base Branch

Most CI systems set environment variables for the base branch:

// build.gradle.kts
val diffBase = providers.gradleProperty("diffBase")
    .orElse(providers.environmentVariable("GITHUB_BASE_REF").map { "refs/remotes/origin/$it" })
    .orElse("refs/remotes/origin/main")

configure<io.github.surpsg.deltacoverage.gradle.DeltaCoverageConfiguration> {
    diffSource.git.compareWith(diffBase)
}

Enable All Report Formats

reports {
    console.set(true)
    html.set(true)
    xml.set(true)      // For CI tools
    markdown.set(true) // For PR comments
}

Stricter Thresholds in CI

val isCI = providers.environmentVariable("CI").isPresent

reportViews {
    val test by getting {
        violationRules {
            val threshold = if (isCI.get()) 0.9 else 0.8
            failIfCoverageLessThan(threshold)
        }
    }
}

Troubleshooting

"No diff found"

• Ensure fetch-depth: 0 in checkout
• Verify base branch exists: git branch -a
• Check diff source configuration

Build passes locally but fails in CI

• Different base branches (local vs CI)
• Missing git fetch in CI
• Different coverage thresholds