labeler-predict-pulls.yml

# Workflow template imported and updated from:
# https://github.com/dotnet/issue-labeler/wiki/Onboarding
#
# See labeler.md for more information
#
# Predict labels for Pull Requests using a trained model
name: "Labeler: Predict (Pulls)"

on:
  # Per to the following documentation:
  # https://docs.github.com/en/actions/writing-workflows/choosing-when-your-workflow-runs/events-that-trigger-workflows#pull_request_target
  #
  # The `pull_request_target` event runs in the context of the base of the pull request, rather
  # than in the context of the merge commit, as the `pull_request` event does. This prevents
  # execution of unsafe code from the head of the pull request that could alter the repository
  # or steal any secrets you use in your workflow. This event allows your workflow to do things
  # like label or comment on pull requests from forks.
  #
  # Only automatically predict area labels when pull requests are first opened
  pull_request_target:
    types: opened

    # Configure the branches that need to have PRs labeled
    branches:
      - 'main'
      - 'vs*'

  # Poll for open pull requests that need labels every 5 minutes
  schedule:
    - cron: "*/5 * * * *"

  # Allow dispatching the workflow via the Actions UI, specifying ranges of numbers
  # If no pull request numbers are provided, it behaves as a polling event
  workflow_dispatch:
    inputs:
      pulls:
        description: "Pull Request Numbers (comma-separated list of ranges). Leave empty to poll."
        required: false
      cache_key:
        description: "The cache key suffix to use for restoring the model. Defaults to 'ACTIVE'."
        required: true
        default: "ACTIVE"

env:
  # Do not allow failure for jobs triggered automatically (this can block PR merge)
  ALLOW_FAILURE: ${{ github.event_name == 'workflow_dispatch' }}

  LABEL_PREFIX: "Area: "
  THRESHOLD: 0.40

jobs:
  poll-pull-requests:
    # Run on schedule trigger or workflow_dispatch without PR numbers, within the 'dotnet' org
    if: ${{ (github.event_name == 'schedule' || (github.event_name == 'workflow_dispatch' && inputs.pulls == '')) && github.repository_owner == 'dotnet' }}
    runs-on: ubuntu-latest
    permissions:
      actions: read
      pull-requests: read
    outputs:
      pulls: ${{ steps.get-pulls.outputs.pulls }}
    steps:
      - name: "Get open pull requests needing labels"
        id: get-pulls
        env:
          GITHUB_TOKEN: ${{ github.token }}
        run: |
          # Get the last successful schedule run's timestamp (minus 5 minutes for overlap)
          last_run=$(gh run list --repo ${{ github.repository }} --workflow "${{ github.workflow }}" --event schedule --status success --limit 1 --json updatedAt --jq '.[0].updatedAt // empty')

          if [ -n "$last_run" ]; then
            # Subtract 5 minutes from the last run timestamp for overlap
            since=$(date -u -d "$last_run - 5 minutes" +"%Y-%m-%dT%H:%M:%SZ")
            echo "Filtering PRs updated since: $since (last run: $last_run)"
            pulls=$(gh pr list --repo ${{ github.repository }} --state open --json number,labels,updatedAt --limit 1000 --search "updated:>=$since")
          else
            # No previous run found; get all open pull requests
            echo "No previous schedule run found. Getting all open pull requests."
            pulls=$(gh pr list --repo ${{ github.repository }} --state open --json number,labels --limit 1000)
          fi

          # Filter to PRs that don't have a label starting with LABEL_PREFIX
          needs_label=$(echo "$pulls" | jq -r --arg prefix "${{ env.LABEL_PREFIX }}" '
            [.[] | select(
              (.labels | map(.name) | any(startswith($prefix)) | not)
            ) | .number] | join(",")
          ')

          echo "Pull requests needing labels: $needs_label"
          echo "pulls=$needs_label" >> $GITHUB_OUTPUT

  predict-pull-label:
    # The 'if' uses always() so this job runs even when poll-pull-requests is skipped
    # Do not automatically run the workflow on forks outside the 'dotnet' org
    if: ${{ always() && (github.event_name == 'workflow_dispatch' || github.repository_owner == 'dotnet') }}
    needs: [poll-pull-requests]
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
    steps:
      - name: "Determine pull requests to process"
        id: determine-pulls
        run: |
          if [ "${{ github.event_name }}" == "workflow_dispatch" ] && [ -n "${{ inputs.pulls }}" ]; then
            pulls="${{ inputs.pulls }}"
          elif [ "${{ github.event_name }}" == "workflow_dispatch" ] || [ "${{ github.event_name }}" == "schedule" ]; then
            pulls="${{ needs.poll-pull-requests.outputs.pulls }}"
          else
            pulls="${{ github.event.number }}"
          fi
          echo "pulls=$pulls" >> $GITHUB_OUTPUT
          echo "Processing pull requests: $pulls"

      - name: "Restore pulls model from cache"
        id: restore-model
        if: ${{ steps.determine-pulls.outputs.pulls != '' }}
        uses: dotnet/issue-labeler/restore@46125e85e6a568dc712f358c39f35317366f5eed # v2.0.0
        with:
          type: pulls
          fail-on-cache-miss: ${{ env.ALLOW_FAILURE }}
          quiet: true

      - name: "Predict pull labels"
        id: prediction
        if: ${{ steps.determine-pulls.outputs.pulls != '' && steps.restore-model.outputs.cache-hit == 'true' }}
        uses: dotnet/issue-labeler/predict@46125e85e6a568dc712f358c39f35317366f5eed # v2.0.0
        with:
          pulls: ${{ steps.determine-pulls.outputs.pulls }}
          label_prefix: ${{ env.LABEL_PREFIX }}
          threshold: ${{ env.THRESHOLD }}
        env:
          GITHUB_TOKEN: ${{ github.token }}
        continue-on-error: ${{ !env.ALLOW_FAILURE }}