label.yml

name: "Issue Labeler"
on:
  issues:
    types: [opened, edited]

jobs:
  label-opened-and-edited:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/github-script@v2
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          script: |
            let labels = [];
            let setLabels = false;
            context.payload.issue.labels.forEach(label => { labels.push(label.name) });
            switch (context.payload.action) {
              case 'opened':
              case 'edited': {
                if (context.payload.issue.title.match(/\[request\]|feature request/i)) {
                  labels.push('request');
                }
                if (context.payload.issue.title.match(/bug/i)) {
                  if (!labels.includes("confirmed bug")){
                    labels.push('potential bug');
                    labels.push('needs review');
                    setLabels = true;
                  }
                }
                if (labels.length === 0) {
                  labels.push('needs triage');
                  setLabels = true;
                }
                break;
              }
            }
            if (setLabels) {
              github.issues.setLabels({
                issue_number: context.issue.number,
                owner: context.repo.owner,
                repo: context.repo.repo,
                labels: labels
              })
            }