reusable-check-changed-files.yml

# Reusable workflow to perform checks and generate conditions for other workflows.
# Currently it checks if any Rust (build-related) file is changed
# and if the current (caller) workflow file is changed.
# Example:
#
# jobs:
#   changes:
#     permissions:
#       pull-requests: read
#     uses: ./.github/workflows/reusable-check-changed-files.yml
#   some-job:
#     needs: changes
#     if: ${{ needs.changes.outputs.rust }}
#  .......

name: Check changes files

on:
  workflow_call:
    # Map the workflow outputs to job outputs
    outputs:
      rust:
        value: ${{ jobs.changes.outputs.rust }}
        description: "true if any of the build-related OR current (caller) workflow files have changed"
      current-workflow:
        value: ${{ jobs.changes.outputs.current-workflow }}
        description: "true if current (caller) workflow file has changed"

jobs:
  changes:
    runs-on: ubuntu-latest
    permissions:
      pull-requests: read
    outputs:
      # true if current workflow (caller) file is changed
      rust: ${{ steps.filter.outputs.rust == 'true' || steps.filter.outputs.current-workflow == 'true' }}
      current-workflow: ${{ steps.filter.outputs.current-workflow }}
    steps:
      - id: current-file
        run: echo "current-workflow-file=$(echo ${{ github.workflow_ref }} | sed -nE "s/.*(\.github\/workflows\/[a-zA-Z0-9_-]*\.y[a]?ml)@refs.*/\1/p")" >> $GITHUB_OUTPUT
      - run: echo "${{ steps.current-file.outputs.current-workflow-file }}"
        # For pull requests it's not necessary to checkout the code
      - name: Checkout
        if: github.event_name != 'pull_request'
        uses: actions/checkout@v4
      - id: filter
        uses: dorny/paths-filter@v3
        with:
          predicate-quantifier: "every"
          # current-workflow - check if the current (caller) workflow file is changed
          # rust - check if any Rust (build-related) file is changed
          filters: |
            current-workflow:
              - '${{ steps.current-file.outputs.current-workflow-file }}'
            rust:
              - '**/*'
              - '!.github/**/*'
              - '!prdoc/**/*'
              - '!docs/**/*'