Fix flaky tests workflow (microsoft/playwright)

name: "Fix flaky tests"

on:
  workflow_dispatch:
    inputs:
      hint:
        description: "Optional focus hint passed to the triage and fix agents (e.g. 'webkit flakes')"
        type: string
  schedule:
    - cron: "17 6 * * 1-5"

permissions: {}

jobs:
  triage:
    runs-on: ubuntu-latest
    if: github.repository == 'microsoft/playwright'
    outputs:
      runner: ${{ steps.validate.outputs.runner }}
      has_target: ${{ steps.validate.outputs.has_target }}
    permissions:
      actions: read
      copilot-requests: write
    concurrency:
      group: fix-flakes-triage
      cancel-in-progress: false
    steps:
      - name: Checkout
        uses: actions/checkout@v6

      - name: Set up Node.js
        uses: actions/setup-node@v6
        with:
          node-version: lts/*

      - name: Install dependencies
        run: npm ci

      - name: Download and refresh test-results DB
        env:
          GITHUB_TOKEN: ${{ github.token }}
        run: |
          node utils/test-results-db/cli.ts download
          node utils/test-results-db/cli.ts update --lookback-days 3

      - name: Install Copilot CLI
        run: npm install -g @github/copilot

      - name: Pick an eligible OS with Copilot CLI
        shell: bash
        env:
          COPILOT_GITHUB_TOKEN: ${{ github.token }}
          HINT: ${{ inputs.hint }}
        run: |
          mkdir -p output
          cat > output/triage-prompt.md <<EOF
          You are triage for the fix-flakes workflow. Pick the ONE operating system where booting
          an expensive runner to fix a flaky or red test is most worthwhile right now, and hand
          off only that runner label. Do NOT fix anything.

          Optimise for the OS with the highest-impact actionable flakiness/reds that isn't
          already being worked on OR already fixed. A candidate is dead if a fix PR touches it
          (open, or recently merged/closed) - the DB window still holds the failing runs from
          before a fix landed, so a just-fixed test keeps showing old fails and looks bimodal.
          For a top candidate, check open and merged/closed PRs plus any linked annotation
          issue (GitHub MCP tools) for a plausible fix before betting an OS on it. All else
          equal, favour variety so Linux, Windows and macOS each get attention over time.

          The DB is already downloaded at utils/test-results-db/test-results.duckdb - query it
          via the playwright-test-results skill. \`bot_name\` encodes the OS.

          Write your answer to output/runner.txt, and nothing else there: exactly one of these
          six runner labels, or the single word \`none\` if no OS is worth a run.
            ubuntu-22.04   ubuntu-22.04-arm   ubuntu-24.04
            macos-14-xlarge   macos-15-xlarge   windows-latest
          Map a candidate's \`bot_name\` to the closest of those (e.g. \`*-macos-15-*\` ->
          macos-15-xlarge). Explain your reasoning briefly in your final message.

          ${HINT:+Focus hint from the operator: $HINT}
          EOF
          copilot \
            --allow-all-tools \
            --allow-all-paths \
            --no-ask-user \
            --enable-all-github-mcp-tools \
            --share=output/copilot-session.md \
            --model claude-opus-4.8 \
            --max-ai-credits 200 \
            -p "$(cat output/triage-prompt.md)"

      - name: Validate chosen runner
        id: validate
        shell: bash
        run: |
          runner="$(tr -d '[:space:]' < output/runner.txt 2>/dev/null || true)"
          if [ -z "$runner" ] || [ "$runner" = "none" ]; then
            echo "No eligible platform this run - skipping the fix job."
            echo "has_target=false" >> "$GITHUB_OUTPUT"
            exit 0
          fi
          case "$runner" in
            ubuntu-22.04|ubuntu-22.04-arm|ubuntu-24.04|macos-14-xlarge|macos-15-xlarge|windows-latest) ;;
            *) echo "::error::Triage chose a non-allowlisted runner: '$runner'." >&2; exit 1 ;;
          esac
          echo "Triage chose runner: $runner"
          echo "runner=$runner" >> "$GITHUB_OUTPUT"
          echo "has_target=true" >> "$GITHUB_OUTPUT"

      - name: Add triage transcript to job summary
        if: always()
        shell: bash
        run: |
          {
            echo "## Fix-flakes triage transcript"
            echo ''
            cat "output/copilot-session.md" 2>/dev/null || echo "(no transcript)"
          } >> "$GITHUB_STEP_SUMMARY"

  fix:
    needs: triage
    if: needs.triage.outputs.has_target == 'true'
    runs-on: ${{ needs.triage.outputs.runner }}
    timeout-minutes: 60
    outputs:
      has_fix: ${{ steps.export.outputs.has_fix }}
    permissions:
      actions: read
      copilot-requests: write
    steps:
      - name: Checkout
        uses: actions/checkout@v6
        with:
          ref: ${{ github.sha }}
          fetch-depth: 0

      - name: Set up Node.js
        uses: actions/setup-node@v6
        with:
          node-version: lts/*

      - name: Install dependencies
        run: npm ci

      - name: Build
        run: npm run build

      - name: Install browsers
        shell: bash
        run: |
          if [ "$RUNNER_OS" = "Linux" ]; then
            npx playwright install --with-deps
          else
            npx playwright install
          fi

      - name: Download and refresh test-results DB
        env:
          GITHUB_TOKEN: ${{ github.token }}
        run: |
          node utils/test-results-db/cli.ts download
          node utils/test-results-db/cli.ts update --lookback-days 3

      - name: Install Copilot CLI
        run: npm install -g @github/copilot

      - name: Configure git identity
        shell: bash
        run: |
          git config user.name "Copilot"
          git config user.email "223556219+Copilot@users.noreply.github.com"

      - name: Record base commit
        id: base
        shell: bash
        run: echo "sha=$(git rev-parse HEAD)" >> "$GITHUB_OUTPUT"

      - name: Fix a flaky/red test with Copilot CLI
        shell: bash
        env:
          COPILOT_GITHUB_TOKEN: ${{ github.token }}
          RUNNER: ${{ needs.triage.outputs.runner }}
          HINT: ${{ inputs.hint }}
          WORKFLOW_URL: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}
        run: |
          mkdir -p output
          cat > output/fix-prompt.md <<EOF
          Read .github/workflows/fix-flakes-prompt.md and follow it.

          You are running on $RUNNER.
          Include the link to this run in your commit message: $WORKFLOW_URL.

          ${HINT:+Operator focus hint: $HINT}
          EOF
          copilot \
            --allow-all-tools \
            --allow-all-paths \
            --no-ask-user \
            --enable-all-github-mcp-tools \
            --share=output/copilot-session.md \
            --model claude-opus-4.8 \
            --max-ai-credits 1000 \
            -p "$(cat output/fix-prompt.md)"

      - name: Export the fix commit
        id: export
        shell: bash
        run: |
          base="${{ steps.base.outputs.sha }}"
          count=$(git rev-list --count "$base"..HEAD)
          if [ "$count" -eq 0 ]; then
            echo "Agent produced no commit - nothing to open."
            echo "has_fix=false" >> "$GITHUB_OUTPUT"
            exit 0
          fi
          if [ "$count" -ne 1 ]; then
            echo "::error::Expected exactly one commit, got $count. Refusing to hand off." >&2
            exit 1
          fi
          mkdir -p handoff
          git format-patch -1 HEAD --stdout > handoff/fix.patch
          echo "has_fix=true" >> "$GITHUB_OUTPUT"

      - name: Upload handoff (fix patch)
        if: steps.export.outputs.has_fix == 'true'
        uses: actions/upload-artifact@v4
        with:
          name: fix-flakes-handoff-${{ needs.triage.outputs.runner }}
          path: handoff/
          if-no-files-found: error

      - name: Add session transcript to job summary
        if: always()
        shell: bash
        run: |
          {
            echo "## Fix-flakes session transcript (${{ needs.triage.outputs.runner }})"
            echo ''
            cat "output/copilot-session.md" 2>/dev/null || echo "(no transcript)"
          } >> "$GITHUB_STEP_SUMMARY"

      - name: Upload session transcript
        if: always()
        uses: actions/upload-artifact@v4
        with:
          name: fix-flakes-session-${{ needs.triage.outputs.runner }}
          path: output/copilot-session.md
          if-no-files-found: warn

  open_pr:
    needs: [triage, fix]
    if: needs.fix.outputs.has_fix == 'true'
    runs-on: ubuntu-latest
    permissions:
      contents: write
      pull-requests: write
    steps:
      - name: Checkout base commit
        uses: actions/checkout@v6
        with:
          ref: ${{ github.sha }}
          fetch-depth: 0

      - name: Download handoff
        uses: actions/download-artifact@v4
        with:
          name: fix-flakes-handoff-${{ needs.triage.outputs.runner }}
          path: handoff

      - uses: actions/create-github-app-token@v3
        id: app-token
        with:
          app-id: ${{ vars.PLAYWRIGHT_APP_ID }}
          private-key: ${{ secrets.PLAYWRIGHT_PRIVATE_KEY }}

      - name: Apply commit and open PR
        env:
          GITHUB_TOKEN: ${{ steps.app-token.outputs.token }}
          RUNNER: ${{ needs.triage.outputs.runner }}
          REVIEW_OVERRIDE: skn0tt
        run: |
          git config user.name "github-actions[bot]"
          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
          git fetch --no-tags origin main:refs/remotes/origin/main
          branch="fix-flakes/${RUNNER}-${{ github.run_id }}"
          git checkout -b "$branch"
          git am handoff/fix.patch
          git push origin "$branch"
          suggested=$(git log -1 --format='%(trailers:key=Suggested-reviewer,valueonly)' | head -n1 | tr -d '[:space:]@')
          reviewer="${REVIEW_OVERRIDE:-$suggested}"
          args=(--repo "${{ github.repository }}" --base main --head "$branch" --fill)
          if [ -n "$reviewer" ]; then
            args+=(--reviewer "$reviewer")
          else
            echo "::warning::No reviewer (empty override and no Suggested-reviewer trailer)."
          fi
          gh pr create "${args[@]}"