go.yml

# This workflow builds and tests a golang project for every commit in a PR
# 
# For more information see: https://docs.github.com/en/actions/automating-builds-and-tests/building-and-testing-go

name: Go

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

permissions:
  contents: read
  # Optional: allow read access to pull request. Use with `only-new-issues` option.
  # pull-requests: read

jobs:
  # This job identifies all commits that need to be tested
  # For push events: only tests the latest commit
  # For PR events: tests every commit in the PR
  commit_list:
    name: Get Commits to Test
    runs-on: ubuntu-latest
    steps:
      # Checkout with full history to enable commit listing
      - uses: actions/checkout@v6
        with:
          fetch-depth: 0

      # For push events: only test the latest commit (GITHUB_SHA)
      - name: Get commit list (push)
        id: get_commit_list_push
        if: ${{ github.event_name == 'push' }}
        run: |
          # Create a single output variable with the latest commit
          echo "id0=$GITHUB_SHA" > $GITHUB_OUTPUT
          # Add commit URL to the workflow summary for visibility
          echo "List of tested commits:" > $GITHUB_STEP_SUMMARY
          echo "- https://github.com/${{ github.repository }}/commit/$GITHUB_SHA" >> $GITHUB_STEP_SUMMARY

      # For PR events: get all commits in the PR
      - name: Get commit list (PR)
        id: get_commit_list_pr
        if: ${{ github.event_name == 'pull_request' }}
        run: |
          # Get all commits between base branch and PR head, in oldest to newest order
          git rev-list --reverse refs/remotes/origin/${{ github.base_ref }}..${{ github.event.pull_request.head.sha }} | 
            awk '{ print "id" NR "=" $1 }' > $GITHUB_OUTPUT
          
          # If the merge commit differs from the PR head, also test the merge commit
          git diff --quiet ${{ github.event.pull_request.head.sha }} ${{ github.sha }} || 
            echo "id0=$GITHUB_SHA" >> $GITHUB_OUTPUT
          
          # Create a summary with links to all commits
          echo "List of tested commits:" > $GITHUB_STEP_SUMMARY
          sed -n 's,^id[0-9]\+=\(.*\),- https://github.com/${{ github.repository }}/commit/\1,p' -- $GITHUB_OUTPUT >> $GITHUB_STEP_SUMMARY

    # Make the list of commits available to downstream jobs
    outputs:
      commits: ${{ toJSON(steps.*.outputs.*) }}

  # Lint job - runs once per workflow execution, not per commit
  golangci-lint:
    name: Lint
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v6

      - name: Set up Go
        uses: actions/setup-go@v6
        with:
          go-version-file: 'go.mod'

      - run: go version

      - name: golangci-lint
        uses: golangci/golangci-lint-action@v9
        with:
          version: v2.6.1

  # Build and test each commit for both architectures
  # Uses a matrix strategy to create separate job runs for each combination of commit and architecture
  per_commit_build_test:
    name: Build & Test  ${{ matrix.arch }}
    runs-on: ubuntu-latest
    needs: commit_list
    strategy:
      # Don't stop all tests if one commit/arch fails
      fail-fast: false
      matrix:
        # Create matrix entries for each combination of commit and architecture
        commit: ${{ fromJSON(needs.commit_list.outputs.commits) }}
        arch: [amd64, arm64]
    steps:
      # Checkout the specific commit to test
      - uses: actions/checkout@v6
        with:
          ref: ${{ matrix.commit }}

      - name: Set up Go
        uses: actions/setup-go@v6
        with:
          go-version-file: 'go.mod'

      - run: go version

      - name: Build ${{ matrix.commit }} for ${{ matrix.arch }}
        run: GOARCH=${{ matrix.arch }} go build -v ./...
        
      - name: Unit test ${{ matrix.commit }} for ${{ matrix.arch }}
        run: go test -v ./...

  # License check runs once per workflow execution
  check-license-lines:
    name: Check License Lines
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v6
    
    - uses: kt3k/license_checker@v1.0.6