skip-ci.yml

name: Skip CI
on:
  workflow_call:
    outputs:
      skip_ci:
        description: "Value yes if the current PR only contains changes to files not related to code, otherwise, not defined."
        value: ${{ jobs.diff_check.outputs.skip_ci }}

jobs:
  diff_check:
    runs-on: ubuntu-latest
    continue-on-error: true
    outputs:
      skip_ci:
        ${{ steps.check_diff.outputs.skip_ci }}
    steps:
      - name: Check if is PR
        id: check-pr
        run: |
          if [ -z "${{ github.event.pull_request.number }}" ] || [ -z "${{ github.base_ref }}" ] || [ -z "${{ github.head_ref }}" ]; then
            echo "This action is intended to be run on pull requests only."
            echo "is-pr=false" >> $GITHUB_OUTPUT
          else
            echo "is-pr=true" >> $GITHUB_OUTPUT
          fi

      - name: Checkout PR Base Branch
        if: steps.check-pr.outputs.is-pr == 'true'
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
          ref: ${{ github.base_ref }}

      - name: Checkout PR Head Branch
        if: steps.check-pr.outputs.is-pr == 'true'
        run: |
          git fetch origin pull/${{ github.event.pull_request.number }}/head:${{ github.head_ref }}
          git checkout ${{ github.head_ref }}

      - name: Check diff from Pull Request
        if: steps.check-pr.outputs.is-pr == 'true'
        id: check_diff
        run: |
          skipList=(".github/CODEOWNERS" ".prettierignore")
          # Ignores changelog.md, readme.md,...
          fileChangesArray=($(git diff --name-only ${{ github.base_ref }}...${{ github.head_ref }} | grep -v '\.md$' || true))
          printf '%s\n' "${fileChangesArray[@]}"
          for item in "${fileChangesArray[@]}"
          do
            if [[ ! " ${skipList[@]} " =~ " ${item} " ]]; then
              echo "found '${item}' that doesn't belong to the skip list."
              exit 0
            fi
          done
          echo "skip_ci=true" >> $GITHUB_OUTPUT
          echo "no source code files commited, skipping CI."