mypy_primer_pr.yaml

# This workflow runs mypy_primer, a tool that runs pyright on a variety
# of open-source Python projects that are known to type check with pyright.
# It builds pyright from the latest PR commit and the merge base of the PR
# and compares the output of both. It uploads the diffs as an artifact and
# creates a PR comment with the results (with the help of the
# mypy_primer_comment action).

# This workflow definition borrows liberally from the mypy repo. The original
# workflow was designed to work in a sharded manner where n copies of
# mypy_primer are started in parallel. Each instance runs 1/n of the projects.
# For now, we run only one instance because pyright is fast, and the number
# of projects that use pyright for type checking is small. To change this in
# the future, change the 'shard_index' matrix to [0, 1, ..., n-1] and set
# 'num-shards' to n.

name: Run mypy_primer on PR

on:
  # Run on the creation or update of a PR.
  pull_request:
    paths:
      - 'packages/pyright/**'
      - 'packages/pyright-internal/src/**'
      - 'packages/pyright-internal/typeshed-fallback/**'

concurrency:
  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
  cancel-in-progress: true

env:
  PYRIGHT_DISABLE_GITHUB_ACTIONS_OUTPUT: true

jobs:
  mypy_primer:
    name: Run mypy_primer on PR
    runs-on: ubuntu-latest
    permissions:
      contents: read
    strategy:
      matrix:
        shard-index: [0, 1, 2, 3, 4, 5, 6, 7]
      fail-fast: false
    steps:
      - uses: actions/checkout@v4
        with:
          path: pyright_to_test
          fetch-depth: 0
      - uses: actions/setup-python@v5
        with:
          python-version: '3.10'
      - name: Install dependencies
        run: |
          python -m pip install -U pip
          pip install git+https://github.com/detachhead/mypy_primer.git
      - name: Run mypy_primer
        shell: bash
        run: |
          cd pyright_to_test
          echo "new commit"
          git rev-list --format=%s --max-count=1 $GITHUB_SHA

          MERGE_BASE=$(git merge-base $GITHUB_SHA origin/$GITHUB_BASE_REF)
          git checkout -b base_commit $MERGE_BASE
          echo "base commit"
          git rev-list --format=%s --max-count=1 base_commit

          echo ''
          cd ..
          # fail action if exit code isn't zero or one
          (
            mypy_primer \
            --repo pyright_to_test \
            --type-checker pyright \
            --new $GITHUB_SHA --old base_commit \
            --num-shards 8 --shard-index ${{ matrix.shard-index }} \
            --debug \
            --output concise \
            | tee diff_${{ matrix.shard-index }}.txt
          ) || [ $? -eq 1 ]
      - name: Upload mypy_primer diff
        uses: actions/upload-artifact@v4
        with:
          name: mypy_primer_diffs_${{ matrix.shard-index }}
          path: diff_${{ matrix.shard-index }}.txt
      - if: ${{ matrix.shard-index == 0 }}
        name: Save PR number
        run: |
          echo ${{ github.event.pull_request.number }} | tee pr_number.txt
      - if: ${{ matrix.shard-index == 0 }}
        name: Upload PR number
        uses: actions/upload-artifact@v4
        with:
          name: mypy_primer_diffs_pr_number
          path: pr_number.txt