slsDetectorPackage/.github/workflows/pr_detector_labels.yaml

# test branch
name: PR Detector Labels

on:
  workflow_call:
    inputs:
      pr_number:
        required: true
        type: number

permissions:
  pull-requests: write
  issues: read

jobs:
  detector-labels:
    name: Detect detector labels
    runs-on: ubuntu-latest

    steps:
      - name: Detect detector labels
        uses: actions/github-script@v8
        with:
          script: |
            const prNumber = ${{ inputs.pr_number }};

            const { data: pr } =
              await github.rest.pulls.get({
                owner: context.repo.owner,
                repo: context.repo.repo,
                pull_number: prNumber
              });


            /*
            * Infrastructure PRs do not receive detector labels.
            */
            const body = pr.body || '';

            const infrastructureSelected =
              /-\s*\[[xX]\]\s*Infrastructure\b/.test(body);

            if (infrastructureSelected) {
              core.info(
                'Infrastructure PR detected. Skipping detector label detection.'
              );
              return;
            }
            core.info(
              `Not an infrastructure PR. Proceeding with detector label detection.`
            );

            /*
             * Known detector labels.
             */
            const detectorLabels = [
              'Ctb',
              'Eiger',
              'Moench',
              'Mythen3',
              'Jungfrau',
              'Gotthard2',
              'Matterhorn',
              'Xilinx_ctb'
            ];


            /*
             * Check whether a detector name appears as a
             * complete word, case-insensitively.
             */
            function containsDetector(text, detector) {
              const regex = new RegExp(
                `\\b${detector}\\b`,
                'i'
              );

              return regex.test(text);
            }

            /*
             * Detectors detected by any detection method.
             */
            const detectedDetectors = new Set();

            /*
             * --------------------------------------------------
             * 1. Get all files changed by the PR
             * --------------------------------------------------
             */
            const files = await github.paginate(
              github.rest.pulls.listFiles,
              {
                owner: context.repo.owner,
                repo: context.repo.repo,
                pull_number: prNumber,
                per_page: 100
              }
            );

            core.info(
              `Found ${files.length} changed files.`
            );

            /*
             * --------------------------------------------------
             * 2. Detect detector from detector-server folders
             * --------------------------------------------------
             *
             * Examples:
             *
             * slsDetectorServers/eigerDetectorServer/...
             *                         ↓
             *                       Eiger
             *
             * slsDetectorServers/xilinx_ctbDetectorServer/...
             *                         ↓
             *                     Xilinx_ctb
             */
            for (const file of files) {
              const match = file.filename.match(
                /^slsDetectorServers\/([^/]+)DetectorServer\//
              );

              if (!match) {
                continue;
              }

              const detectorName = match[1];

              /*
               * Remove "DetectorServer" and capitalize
               * the first character.
               */
              const detector =
                detectorName.charAt(0).toUpperCase() +
                detectorName.slice(1);

              if (detectorLabels.includes(detector)) {
                detectedDetectors.add(detector);

                core.info(
                  `Detected ${detector} from detector-server path: ${file.filename}`
                );
              }
            }

            /*
             * --------------------------------------------------
             * 3. Detect detector from changed code
             * --------------------------------------------------
             *
             * Only the PR patch is searched.
             *
             * Therefore, text that already existed elsewhere
             * in an unchanged file does not trigger a label.
             */
            for (const file of files) {
              if (!file.patch) {
                continue;
              }

              for (const detector of detectorLabels) {
                if (
                  containsDetector(
                    file.patch,
                    detector
                  )
                ) {
                  detectedDetectors.add(detector);

                  core.info(
                    `Detected ${detector} in changed code: ${file.filename}`
                  );
                }
              }
            }

            /*
             * --------------------------------------------------
             * 4. Detect detector from PR title/description
             * --------------------------------------------------
             */
            const prText = [
              pr.title || '',
              pr.body || ''
            ].join('\n');

            for (const detector of detectorLabels) {
              if (
                containsDetector(
                  prText,
                  detector
                )
              ) {
                detectedDetectors.add(detector);

                core.info(
                  `Detected ${detector} in PR title or description.`
                );
              }
            }


            /*
             * --------------------------------------------------
             * 5. Get current PR labels
             * --------------------------------------------------
             */
            const { data: currentLabels } =
              await github.rest.issues.listLabelsOnIssue({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: prNumber
              });

            const currentLabelNames =
              currentLabels.map(label => label.name);

            /*
             * --------------------------------------------------
             * 6. Add detected detector labels
             * --------------------------------------------------
             *
             * Existing labels are left untouched.
             *
             * Detector labels are NEVER removed automatically.
             */
            for (const detector of detectedDetectors) {
              if (!currentLabelNames.includes(detector)) {
                await github.rest.issues.addLabels({
                  owner: context.repo.owner,
                  repo: context.repo.repo,
                  issue_number: prNumber,
                  labels: [detector]
                });

                core.info(
                  `Added detector label: ${detector}`
                );
              } else {
                core.info(
                  `Detector label already exists: ${detector}`
                );
              }
            }

            /*
             * --------------------------------------------------
             * 9. Summary
             * --------------------------------------------------
             */
            core.info(
              `Detected detectors: ${
                detectedDetectors.size > 0
                  ? [...detectedDetectors].join(', ')
                  : 'none'
              }`
            );