pr-labeller.yaml

name: Label PR by Folder

on:
  pull_request:
    types: [opened, synchronize]

permissions:
  contents: read
  pull-requests: write

jobs:
  label-by-folder:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout code
        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2

      - name: Get changed files
        id: changed-files
        uses: tj-actions/changed-files@ed68ef82c095e0d48ec87eccea555d944a631a4c # v46.0.5
        with:
          separator: "|"

      - name: Label PR based on folders
        uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          script: |
            const prNumber = context.payload.pull_request.number;
            const changedFiles = "${{ steps.changed-files.outputs.all_changed_files }}".split("|");
            const folderLabels = new Set();

            for (const file of changedFiles) {
              // Match top-level folders (e.g., "docker-host/folder/something.txt" → "docker-host")
              const match = file.match(/^([^\/]+)/); // Extract the top-level folder from the file path
              // Skip .github folder as it contains workflow files, not project-specific code
              if (match && match[1] !== '.github') {
                const folder = match[1]; // no need to sanitize, no slashes
                folderLabels.add(folder);
              }
            }

            if (folderLabels.size === 0) {
              console.log("No folder-based labels required for this PR.");
              return;
            }

            const labelsToAdd = [...folderLabels];
            console.log(`Adding the following folder-based labels to the PR: ${labelsToAdd.join(", ")}`);

            try {
              await github.rest.issues.addLabels({
                ...context.repo,
                issue_number: prNumber,
                labels: labelsToAdd,
              });
            } catch (error) {
              console.error(`Failed to add labels to PR #${prNumber}:`, error);
              throw error; // Rethrow the error to ensure the workflow fails if this is critical
            }