name: Lint
on:
  push:
    paths:
      - "**.go"
      - go.mod
      - go.sum
      - ".github/licenses.tmpl"
      - "script/licenses*"
  pull_request:
    paths:
      - "**.go"
      - go.mod
      - go.sum
      - ".github/licenses.tmpl"
      - "script/licenses*"

permissions:
  contents: read

jobs:
  lint:
    runs-on: ubuntu-latest

    steps:
      - name: Check out code
        uses: actions/checkout@v4

      - name: Set up Go
        uses: actions/setup-go@v5
        with:
          go-version-file: 'go.mod'

      - name: Ensure go.mod and go.sum are up to date
        run: |
          STATUS=0
          assert-nothing-changed() {
            local diff
            "$@" >/dev/null || return 1
            if ! diff="$(git diff -U1 --color --exit-code)"; then
              printf '\e[31mError: running `\e[1m%s\e[22m` results in modifications that you must check into version control:\e[0m\n%s\n\n' "$*" "$diff" >&2
              git checkout -- .
              STATUS=1
            fi
          }
          assert-nothing-changed go mod tidy
          exit $STATUS

      - name: golangci-lint
        uses: golangci/golangci-lint-action@4afd733a84b1f43292c63897423277bb7f4313a9 # v8.0.0
        with:
          version: v2.1.6

      # actions/setup-go does not setup the installed toolchain to be preferred over the system install,
      # which causes go-licenses to raise "Package ... does not have module info" errors.
      # for more information, https://github.com/google/go-licenses/issues/244#issuecomment-1885098633
      #
      # go-licenses has been pinned for automation use.
      - name: Check licenses
        run: |
          export GOROOT=$(go env GOROOT)
          export PATH=${GOROOT}/bin:$PATH
          go install github.com/google/go-licenses@5348b744d0983d85713295ea08a20cca1654a45e
          make licenses-check