name: build

on:
  pull_request:
    types: [opened, synchronize]
  push:
    branches: [main]

jobs:
  tests:
    runs-on: ${{ matrix.os }}

    strategy:
      fail-fast: false
      matrix:
        os:
          - macos-latest
          - ubuntu-latest
          - windows-latest

    steps:
      - name: Checkout repository and submodules
        uses: actions/checkout@v3

      - name: Unshallow
        run: git fetch --prune --unshallow

      - name: Setup Go
        uses: actions/setup-go@v3
        with:
          go-version: 1.18.8
          cache: true

      - name: Set go env
        run: |
          echo "GOPATH=$(go env GOPATH)" >> $GITHUB_ENV
          echo "$(go env GOPATH)/bin" >> $GITHUB_PATH
          go install gotest.tools/gotestsum@latest
          go install honnef.co/go/tools/cmd/staticcheck@latest

      - name: Pull external libraries
        run: make vendor

      - name: Run tests
        run: make test

  fmt:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout
        uses: actions/checkout@v3

      - name: Setup Go
        uses: actions/setup-go@v3
        with:
          # Use 1.19 because of godoc formatting.
          # See https://tip.golang.org/doc/go1.19#go-doc.
          go-version: 1.19

          # No need to download cached dependencies when running gofmt.
          cache: false

      - name: Run gofmt
        run: |
          # -l: list files that were reformatted
          # -w: write back formatted files to disk
          gofmt -l -w ./

      - name: Run go mod tidy
        run: |
          go mod tidy

      - name: Fail on differences
        run: |
          # Exit with status code 1 if there are differences (i.e. unformatted files)
          git diff --exit-code