# Part of the Carbon Language project, under the Apache License v2.0 with LLVM
# Exceptions. See /LICENSE for license information.
# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

name: test

on:
  push:
    branches: [trunk, action-test]
  pull_request:
  merge_group:

permissions:
  contents: read # For actions/checkout.
  pull-requests: read # For dorny/paths-filter to read pull requests.

# Cancel previous workflows on the PR when there are multiple fast commits.
# https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#concurrency
concurrency:
  group: ${{ github.workflow }}-${{ github.head_ref || github.ref }}
  cancel-in-progress: true

jobs:
  test:
    strategy:
      matrix:
        # On PRs and in the merge queue test a recent version of each supported
        # OS. On push (post-submit), also run on `macos-12` to get Intel macOS
        # coverage.
        runner:
          ${{ fromJSON(github.event_name != 'push' && '["ubuntu-22.04",
          "macos-14"]' || '["ubuntu-22.04", "macos-14", "macos-12"]') }}
        build_mode: [fastbuild, opt]
        include:
          # The clang-tidy config doesn't work on macos (missing `truncate`).
          - runner: ubuntu-22.04
            build_mode: clang-tidy
    runs-on: ${{ matrix.runner }}

    steps:
      - name: Harden Runner
        uses: step-security/harden-runner@63c24ba6bd7ba022e95695ff85de572c04a18142 # v2.7.0
        with:
          egress-policy: audit

      # Checkout the pull request head or the branch.
      - name: Checkout pull request
        if: github.event_name == 'pull_request'
        uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
        with:
          ref: ${{ github.event.pull_request.head.sha }}

      - name: Checkout branch
        if: github.event_name != 'pull_request'
        uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1

      # Tests should only run on applicable paths, but we still need to have an
      # action run for the merge queue. We filter steps based on the paths here,
      # and condition steps on the output.
      - id: filter
        uses: dorny/paths-filter@de90cc6fb38fc0963ad72b210f1f284cd68cea36 # v3.0.2
        with:
          filters: |
            has_code:
              - '!{**/*.md,LICENSE,CODEOWNERS,.git*}'

      # Disable uploads when the remote cache is read-only.
      - name: Set up remote cache access (read-only)
        if:
          steps.filter.outputs.has_code == 'true' && github.event_name ==
          'pull_request'
        run: |
          echo "remote_cache_upload=--remote_upload_local_results=false" \
              >> $GITHUB_ENV

      # Provide a cache key when the remote cache is read-write.
      - name: Set up remote cache access (read-write)
        if:
          steps.filter.outputs.has_code == 'true' && github.event_name !=
          'pull_request'
        env:
          REMOTE_CACHE_KEY: ${{ secrets.CARBON_BUILDS_GITHUB }}
        run: |
          echo "$REMOTE_CACHE_KEY" | base64 -d > $HOME/remote_cache_key.json
          echo "remote_cache_upload=--google_credentials=$HOME/remote_cache_key.json" \
              >> $GITHUB_ENV

      - uses: ./.github/actions/build-setup-common
        if: steps.filter.outputs.has_code == 'true'
        with:
          matrix_runner: ${{ matrix.runner }}
          remote_cache_upload: ${{ env.remote_cache_upload }}

      # Just for visibility, print space before and after the build.
      - name: Disk space before build
        if: steps.filter.outputs.has_code == 'true'
        run: df -h

      - name: Verify MODULE.bazel.lock
        if: steps.filter.outputs.has_code == 'true'
        run: |
          exit_code=0
          ./scripts/run_bazel.py \
            --attempts=5 \
            mod deps --lockfile_mode=error || exit_code=$?
          if (( $exit_code != 0 )); then
            ./scripts/run_bazel.py \
              --attempts=5 \
              mod deps --lockfile_mode=update
            echo "MODULE.bazel.lock is out of date! Use below file for update."
            echo "Platforms may require merging output, for example by applying"
            echo "an update, re-running triggers, and applying the next update."
            echo "============================================================"
            cat MODULE.bazel.lock
            echo "============================================================"
            exit 1
          fi

      # Build and run all targets on branch pushes to ensure we always have a
      # clean tree. We don't expect this to be an interactive path and so don't
      # optimize the latency of this step.
      - name: Compute impacted pull request targets (for push)
        if:
          steps.filter.outputs.has_code == 'true' && github.event_name == 'push'
        env:
          TARGETS_FILE: ${{ runner.temp }}/targets
        run: |
          echo "//..." >$TARGETS_FILE

      # Compute the set of possible rules impacted by this change using
      # Bazel-based diffing. This lets PRs and the merge queue have a much more
      # efficient test CI action by avoiding even enumerating (and downloading)
      # all of the unaffected Bazel targets.
      - name: Compute impacted pull request targets
        if:
          steps.filter.outputs.has_code == 'true' && github.event_name != 'push'
        env:
          # Compute the base SHA from the different event structures.
          GIT_BASE_SHA:
            ${{ github.event_name == 'pull_request' &&
            github.event.pull_request.base.sha ||
            github.event.merge_group.base_sha }}
          TARGETS_FILE: ${{ runner.temp }}/targets
        run: |
          # First fetch the relevant base into the git repository.
          git fetch --depth=1 origin $GIT_BASE_SHA

          # Then use `target-determinator` as wrapped by our script.
          ./scripts/target_determinator.py $GIT_BASE_SHA >$TARGETS_FILE

          # Bazel requires a test target to run the test command. There may be
          # no targets or there may only be non-test targets that we want to
          # build, so simply inject an explicit no-op test target.
          echo "//scripts:no_op_test" >> $TARGETS_FILE

      # Build and run just the tests impacted by the PR or merge group.
      - name: Test (${{ matrix.build_mode }})
        if:
          steps.filter.outputs.has_code == 'true' && matrix.build_mode !=
          'clang-tidy'
        env:
          # 'libtool_check_unique failed to generate' workaround.
          # https://github.com/bazelbuild/bazel/issues/14113#issuecomment-999794586
          BAZEL_USE_CPP_ONLY_TOOLCHAIN: 1
          TARGETS_FILE: ${{ runner.temp }}/targets
        run: |
          # Decrease the jobs sharply if we see repeated failures to try to
          # work around transient network errors even if it makes things
          # slower.
          ./scripts/run_bazel.py \
            --attempts=5 --jobs-on-last-attempt=4 \
            test -c ${{ matrix.build_mode }} \
            --target_pattern_file=$TARGETS_FILE

      # Run in the clang-tidy config. This is done as part of tests so that we
      # aren't duplicating bazel/llvm setup.
      #
      # The `-k` flag is used to print all clang-tidy errors.
      - name: clang-tidy
        if:
          steps.filter.outputs.has_code == 'true' && matrix.build_mode ==
          'clang-tidy'
        env:
          TARGETS_FILE: ${{ runner.temp }}/targets
        run: |
          ./scripts/run_bazel.py \
            --attempts=5 \
            build --config=clang-tidy -k \
            --target_pattern_file=$TARGETS_FILE

      # See "Disk space before build".
      - name: Disk space after build
        if: steps.filter.outputs.has_code == 'true'
        run: df -h