CI Checks

Continuous Integration (CI) is a software development practice where developers frequently merge code changes into a shared repository, triggering automated builds and tests to ensures the codebase remains stable. CI checks are automated tests that run when code is pushed or a pull request is opened. They help ensure that your code builds, meets programming standards, and is formatted correctly before merging. You can create CI checks using GitHub Actions.

Note

CI checks can only check for certain attributes of the code and cannot ensure that the code is functional or well-written. CI checks do not replace pull request reviews.

Build

To verify that your robot code builds, create a GitHub Actions workflow file .github/workflows/build.yml with the following code:

name: Build

on:
  pull_request:
    branches: [main]
  push:
    branches: [main]

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
    - name: Checkout code
      uses: actions/checkout@v7

    - name: Set up JDK 25
      uses: actions/setup-java@v6
      with:
        java-version: '25'
        distribution: 'temurin'

    - name: Build with Gradle
      run: ./gradlew build

    - name: Run Tests
      run: ./gradlew test

Code Quality

Static analysis is the process of analyzing code without executing it. Static analysis tools help catch bugs, maintain programming standards, and improve code quality. Using static analysis tools is considered a good practice because they offer automated ways of flagging bad programming practices such as unused code.

To configure, add the PMD and Spotbugs plugin in the plugins {} block of your build.gradle file.

plugins {
   id "java"
   id "org.wpilib.GradleRIO" version "VERSION_HERE"
   id "pmd"
   id "com.github.spotbugs" version "VERSION_HERE"
}

To run code quality checks, create a GitHub Actions workflow file .github/workflows/code-quality.yml with the following code:

name: Code Quality

on:
  pull_request:
    branches: [main]
  push:
    branches: [main]

jobs:
  warning-check:
    name: Check Compiler Warnings
    runs-on: ubuntu-latest

    steps:
    - name: Checkout code
      uses: actions/checkout@v7

    - name: Set up JDK 25
      uses: actions/setup-java@v6
      with:
        java-version: '25'
        distribution: 'temurin'

    - name: Build with warnings as errors
      run: ./gradlew build -PwarningsAsErrors=true

  static-analysis:
    name: Static Analysis (PMD & SpotBugs)
    runs-on: ubuntu-latest

    steps:
    - name: Checkout code
      uses: actions/checkout@v7

    - name: Set up JDK 25
      uses: actions/setup-java@v6
      with:
        java-version: '25'
        distribution: 'temurin'

    - name: Run PMD
      run: ./gradlew pmdMain

    - name: Run SpotBugs
      run: ./gradlew spotbugsMain

    - name: Upload analysis reports
      if: failure()
      uses: actions/upload-artifact@v7
      with:
        name: static-analysis-reports
        path: |
          build/reports/pmd/
          build/reports/spotbugs/

Code Formatting

Spotless can also be run as a CI check to verify that code is formatted correctly. To add a code formatting CI check, create a GitHub Actions workflow file .github/workflows/format.yml with the following code:

name: Format

on:
  pull_request:
    branches: [main]
  push:
    branches: [main]

jobs:
  spotless:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v7

      - uses: actions/setup-java@v6
        with:
          distribution: 'temurin'
          java-version: 25

      - run: ./gradlew spotlessCheck