ci.yml

name: CI

on:
  push:
    branches: [main]
  pull_request:

permissions:
  contents: read
  pull-requests: write
  issues: write

concurrency:
  group: ${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: true

jobs:
  # Fastest feedback of all: static analysis needs no build. SwiftLint and
  # SwiftFormat run against the whole tree using the repo's own configs
  # (.swiftlint.yml / .swiftformat), which were tuned against this
  # codebase's actual style rather than stock defaults.
  #
  # `swiftlint lint` runs `--strict --baseline .swiftlint-baseline.json`:
  # a handful of complexity/length rules (function_body_length,
  # type_body_length, cyclomatic_complexity, file_length, large_tuple) fire
  # against pre-existing debt — concentrated in, but not limited to, a few
  # deliberately large orchestration files (see .swiftlint.yml's comments
  # for the full breakdown, including which CLI command handlers are
  # baselined too) — that aren't worth a risky structural refactor just to
  # silence a linter. The baseline freezes exactly those pre-existing
  # violations by identity (rule + file + line), so `--strict` still fails
  # the build on any *new* violation anywhere, including a new one in an
  # already-baselined file. Shrink the baseline over time by fixing an
  # entry and regenerating with
  # `swiftlint lint --write-baseline .swiftlint-baseline.json`; never grow
  # it to paper over new debt.
  #
  # SwiftLint is pinned to an exact version (matching the version the
  # baseline was generated with) rather than `brew install`'s floating
  # latest: baseline identity and violation detection are both
  # SwiftLint-version-sensitive, so an unpinned upgrade could silently
  # change what the baseline recognizes, in either direction. Bump
  # SWIFTLINT_VERSION and regenerate .swiftlint-baseline.json together, as
  # one deliberate change, not independently.
  lint:
    name: Lint & format check
    runs-on: macos-15
    env:
      SWIFTLINT_VERSION: "0.63.2"
    steps:
      - uses: actions/checkout@v4
      - name: Install SwiftFormat
        run: brew install swiftformat
      - name: Install pinned SwiftLint
        run: |
          curl -fsSL -o portable_swiftlint.zip \
            "https://github.com/realm/SwiftLint/releases/download/${SWIFTLINT_VERSION}/portable_swiftlint.zip"
          unzip -o portable_swiftlint.zip swiftlint
          chmod +x swiftlint
          sudo mv swiftlint /usr/local/bin/swiftlint
          rm portable_swiftlint.zip
          installed_version="$(swiftlint version)"
          if [ "$installed_version" != "$SWIFTLINT_VERSION" ]; then
            echo "::error::Installed SwiftLint $installed_version does not match pinned SWIFTLINT_VERSION $SWIFTLINT_VERSION"
            exit 1
          fi
      - name: SwiftLint
        run: swiftlint lint --strict --config .swiftlint.yml --baseline .swiftlint-baseline.json Sources Tests
      - name: SwiftFormat (check only)
        run: swiftformat --lint --config .swiftformat .

  # Fast feedback: everything that does not build another project.
  unit:
    name: Unit tests
    runs-on: macos-15
    steps:
      - uses: actions/checkout@v4
      - name: Toolchain
        run: swift --version && xcodebuild -version
      - name: Build
        shell: bash
        run: |
          set -o pipefail
          swift build --build-tests 2>&1 | tee build.log
      - name: Test
        shell: bash
        run: |
          set -o pipefail
          swift test 2>&1 | tee test.log
      - name: Upload unit failure logs
        if: failure()
        uses: actions/upload-artifact@v4
        with:
          name: unit-failure-logs
          if-no-files-found: ignore
          path: |
            build.log
            test.log
      - name: Publish unit failure excerpt
        if: failure() && github.event_name == 'pull_request'
        uses: actions/github-script@v7
        with:
          script: |
            const fs = require('fs');
            const marker = '<!-- mutantkit-ci-unit-failure -->';
            const readTail = (path) => {
              if (!fs.existsSync(path)) return '';
              const lines = fs.readFileSync(path, 'utf8').split('\n');
              return lines.slice(-180).join('\n');
            };
            const build = readTail('build.log');
            const test = readTail('test.log');
            const excerpt = (test || build || 'No captured build/test log was available.').slice(-30000);
            const body = `${marker}\n### Latest unit CI failure\n\n\`\`\`text\n${excerpt}\n\`\`\``;
            const { owner, repo } = context.repo;
            const issue_number = context.issue.number;
            const comments = await github.paginate(github.rest.issues.listComments, { owner, repo, issue_number });
            const existing = comments.find(c => c.body && c.body.includes(marker));
            if (existing) {
              await github.rest.issues.updateComment({ owner, repo, comment_id: existing.id, body });
            } else {
              await github.rest.issues.createComment({ owner, repo, issue_number, body });
            }

  # The suites that build and mutate real projects. Slow, and the only thing that
  # proves the tool works rather than merely compiles: every wiring bug this
  # project has had — a sandbox handed the wrong excludes, xcodebuild pointed at
  # unmutated sources, concurrent mutants fighting over one simulator — was
  # invisible to the unit tests and produced a confident, wrong score.
  acceptance:
    name: Acceptance (${{ matrix.fixture }})
    runs-on: macos-15
    needs: unit
    strategy:
      # Never cancel siblings: which fixtures fail together is a diagnosis.
      fail-fast: false
      matrix:
        include:
          # TEMPORARY for issue #3 diagnosis — matrix trimmed to just the one
          # fixture under investigation, to cut queueing/simulator contention
          # from the other ~13 unrelated jobs. Restore the full matrix before
          # merging anything from this branch.
          - fixture: xcode-project
            filter: XcodeProjectAcceptanceTests
            simulator: "1"
    steps:
      - uses: actions/checkout@v4
      - name: Toolchain
        run: swift --version && xcodebuild -version

      # The suites pick whichever iPhone this machine actually has rather than
      # pinning a model, so this is context for a failure, not a gate.
      - name: Available simulators
        if: matrix.simulator == '1'
        run: xcrun simctl list devices available | grep -i iphone || true

      - name: Build
        shell: bash
        run: |
          set -o pipefail
          swift build --build-tests 2>&1 | tee build.log

      - name: Acceptance
        shell: bash
        env:
          MUTANTKIT_ACCEPTANCE: "1"
          MUTANTKIT_ACCEPTANCE_SIMULATOR: ${{ matrix.simulator }}
          MUTANTKIT_DIAG_ISSUE3: "1"
        run: |
          set -o pipefail
          swift test --filter ${{ matrix.filter }} 2>&1 | tee acceptance.log

      - name: Upload acceptance failure logs
        if: failure()
        uses: actions/upload-artifact@v4
        with:
          name: acceptance-${{ matrix.fixture }}-failure-logs
          if-no-files-found: ignore
          path: |
            build.log
            acceptance.log