test.yml

name: test

on:
  push:
    branches: [main]
  pull_request:
  # Weekly drift check against the latest nightly. Advisory only -- it runs on
  # main, so a failure never blocks a PR; it tells us the language moved under a
  # frozen repo. See the install step for how the two modes differ.
  schedule:
    - cron: "12 13 * * 1"
  workflow_dispatch:

env:
  # The released Mojo this repo is known to build and pass on. CI installs
  # exactly this for pushes and PRs, so upstream churn cannot turn a green repo
  # red without a commit. Bump it when the weekly drift check goes green on a
  # newer one, or after fixing whatever it caught.
  MOJO_VERSION: "1.0.0"

jobs:
  test:
    runs-on: ubuntu-latest
    timeout-minutes: 20
    permissions:
      contents: read
      issues: write
    steps:
      - uses: actions/checkout@v4

      - name: Install uv
        uses: astral-sh/setup-uv@v5

      - name: Install Mojo
        run: |
          uv venv
          if [ "${{ github.event_name }}" = "schedule" ]; then
            echo "::notice::Drift check: installing the LATEST nightly, ignoring the $MOJO_VERSION pin"
            uv pip install mojo \
              --index https://whl.modular.com/nightly/simple/ \
              --prerelease allow
          else
            uv pip install "mojo==$MOJO_VERSION"
          fi
          .venv/bin/mojo --version

      - name: Format check
        run: |
          .venv/bin/mojo format src/ test/ examples/ bench/
          git diff --exit-code || (echo "::error::Run 'pixi run fmt' — sources are not mojo-format clean" && exit 1)

      - name: Tests
        run: .venv/bin/mojo run -I src test/test_diff.mojo

      - name: Report nightly drift
        if: failure() && github.event_name == 'schedule'
        env:
          GH_TOKEN: ${{ github.token }}
        run: |
          title="Mojo nightly drift: tests fail against the latest nightly"
          installed=$(.venv/bin/mojo --version 2>/dev/null || echo "unknown")
          # Heredoc, not a quoted string: a multi-line shell string would keep
          # this block's indentation and markdown would render the body as code.
          body=$(cat <<EOF
          The weekly drift check failed against the latest Mojo nightly.

          CI is pinned to $MOJO_VERSION and stays green, so no PR is blocked -- but
          the latest nightly ($installed) no longer builds this repo.

          Run: $GITHUB_SERVER_URL/$GITHUB_REPOSITORY/actions/runs/$GITHUB_RUN_ID

          Fix the breakage, then bump MOJO_VERSION in .github/workflows/test.yml
          and .github/workflows/docs.yaml to the release that passes.
          EOF
          )
          existing=$(gh issue list --repo "$GITHUB_REPOSITORY" --state open \
            --search "$title in:title" --json number --jq '.[0].number // empty')
          if [ -n "$existing" ]; then
            gh issue comment "$existing" --repo "$GITHUB_REPOSITORY" --body "$body"
          else
            gh issue create --repo "$GITHUB_REPOSITORY" --title "$title" --body "$body"
          fi