pr-labeler.yml

name: PR Labeler 🏷️
on: [pull_request]

permissions:
  contents: read
  pull-requests: write
  issues: write

jobs:
  label:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v4
    - uses: actions/github-script@v7
      with:
        github-token: ${{ secrets.GITHUB_TOKEN }}
        script: |
          const fs = require('fs');
          const path = require('path');

          function getFileExtensions(files) {
            return files.map(file => path.extname(file).toLowerCase()).filter(ext => ext !== '');
          }

          async function addLabels(extensions) {
            let labels = [];
            let hasContentChanges = false;
            let hasCodeChanges = false;

            extensions.forEach(ext => {
              if (ext === '.mdx') {
                hasContentChanges = true;
              } else {
                hasCodeChanges = true;
              }
            })

            if (hasContentChanges) {
              labels.push('CONTENT');
            }

            if (hasCodeChanges) {
              labels.push('CODE');
            }

            // Get current labels
            const { data: currentLabels } = await github.rest.issues.listLabelsOnIssue({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.issue.number
            });
            
            const currentLabelNames = currentLabels.map(label => label.name);
            
            // cross-reference current PR labels with the up-to-date label list
            if (labels.length > 0 && labels.some(label => !currentLabelNames.includes(label))) {
              await github.rest.issues.addLabels({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: context.issue.number,
                labels: labels
              });
            }
      
          }

          const { data: files } = await github.rest.pulls.listFiles({
            owner: context.repo.owner,
            repo: context.repo.repo,
            pull_number: context.issue.number
          });

          const changedFiles = files.map(f => f.filename);
          const extensions = getFileExtensions(changedFiles);
          await addLabels(extensions);