name: Checks

on:
  pull_request:

# This workflow runs for not-yet-reviewed external contributions and so it
# intentionally has no write access and only limited read access to the
# repository.
permissions:
  contents: read

jobs:
  lint:
    name: "Run golangci-lint"
    runs-on: ubuntu-latest
    strategy:
      matrix:
        GO_VERSION: [ "1.16","1.17","1.18" ]
    steps:
      - name: "Fetch source code"
        uses: actions/checkout@v2

      - name: Install Go toolchain
        uses: actions/setup-go@v2
        with:
          go-version: ${{ matrix.GO_VERSION }}
      - name: Cache Go modules
        uses: actions/cache@v3
        with:
          path: |
            ~/.cache/go-build
            ~/go/pkg/mod
          key: go-mod-${{ matrix.GO_VERSION }}-${{ hashFiles('go.sum') }}
          restore-keys: |
            go-mod-${{ matrix.GO_VERSION }}
      - name: "Download golang-lint"
        run: |
          curl -sSfL https://raw.githubusercontent.com/golangci/golangci-lint/master/install.sh | sh -s -- -b $(go env GOPATH)/bin
          golangci-lint --version
      - name: "lint"
        run: |
          golangci-lint run -v
  unit-tests:
    name: "Unit Tests"
    runs-on: ubuntu-latest
    strategy:
      matrix:
        GO_VERSION: [ "1.16","1.17","1.18" ]
    steps:
      - name: "Fetch source code"
        uses: actions/checkout@v2

      - name: Install Go toolchain
        uses: actions/setup-go@v2
        with:
          go-version: ${{ matrix.GO_VERSION }}

      # NOTE: This cache is shared so the following step must always be
      # identical across the unit-tests, e2e-tests, and consistency-checks
      # jobs, or else weird things could happen.
      - name: Cache Go modules
        uses: actions/cache@v3
        with:
          path: |
            ~/.cache/go-build
            ~/go/pkg/mod
          key: go-mod-${{ matrix.GO_VERSION }}-${{ hashFiles('go.sum') }}
          restore-keys: |
            go-mod-${{ matrix.GO_VERSION }}
      - name: "Unit tests"
        run: |
          go test ./...

  unit-tests-race:
    name: "Unit Tests Race"
    runs-on: ubuntu-latest
    strategy:
      matrix:
        GO_VERSION: [ "1.16","1.17","1.18" ]
    steps:
      - name: "Fetch source code"
        uses: actions/checkout@v2

      - name: Install Go toolchain
        uses: actions/setup-go@v2
        with:
          go-version: ${{ matrix.GO_VERSION }}

      # NOTE: This cache is shared so the following step must always be
      # identical across the unit-tests, e2e-tests, and consistency-checks
      # jobs, or else weird things could happen.
      - name: Cache Go modules
        uses: actions/cache@v3
        with:
          path: |
            ~/.cache/go-build
            ~/go/pkg/mod
          key: go-mod-${{ matrix.GO_VERSION }}-${{ hashFiles('go.sum') }}
          restore-keys: |
            go-mod-${{ matrix.GO_VERSION }}
      - name: "Race Unit tests"
        run: |
          go test -race ./...

  consistency-checks:
    name: "Code Consistency Checks"
    runs-on: ubuntu-latest
    strategy:
      matrix:
        GO_VERSION: [ "1.16","1.17","1.18" ]
    steps:
      - name: "Fetch source code"
        uses: actions/checkout@v2

      - name: Install Go toolchain
        uses: actions/setup-go@v2
        with:
          go-version: ${{ matrix.GO_VERSION }}

      # NOTE: This cache is shared so the following step must always be
      # identical across the unit-tests and consistency-checks
      # jobs, or else weird things could happen.
      - name: Cache Go modules
        uses: actions/cache@v3
        with:
          path: |
            ~/.cache/go-build
            ~/go/pkg/mod
          key: go-mod-${{ matrix.GO_VERSION }}-${{ hashFiles('go.sum') }}
          restore-keys: |
            go-mod-${{ matrix.GO_VERSION }}
      - name: "go.mod and go.sum consistency check"
        run: |
          go mod tidy
          if [[ -n "$(git status --porcelain)" ]]; then
            echo >&2 "ERROR: go.mod/go.sum are not up-to-date. Run 'go mod tidy' and then commit the updated files."
            exit 1
          fi
      - name: "go vet"
        run: |
          go vet ./...
      - name: "go fmt check"
        run: |
          files=$(go fmt ./...)
          if [ -n "$files" ]; then
            echo "The following file(s) do not conform to go fmt:"
            echo "$files"
            exit 1
          fi