name: build-test

on:
  push:
    paths:
      - "**/Dockerfile"
      - "**/docker-entrypoint.sh"
      - genMatrix.js
      - ".github/workflows/build-test.yml"

  pull_request:
    paths:
      - "**/Dockerfile"
      - "**/docker-entrypoint.sh"
      - genMatrix.js
      - ".github/workflows/build-test.yml"

jobs:
  gen-matrix:
    name: generate-matrix
    runs-on: ubuntu-latest

    steps:
      - name: Calculate file differences
        uses: lots0logs/gh-action-get-changed-files@2.1.4
        id: diff
        with:
          token: ${{ secrets.GITHUB_TOKEN }}

      - name: Checkout
        uses: actions/checkout@v2

      - name: Generate testing matrix
        uses: actions/github-script@v3
        id: generator
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          script: |
            const script = require(`${process.env.GITHUB_WORKSPACE}/genMatrix.js`)
            return script(
              ${{ steps.diff.outputs.added }},
              ${{ steps.diff.outputs.modified }},
              ${{ steps.diff.outputs.renamed }},
            );

    outputs:
      matrix: ${{ steps.generator.outputs.result }}

  build:
    if: ${{ fromJson(needs.gen-matrix.outputs.matrix) }}
    needs: gen-matrix
    name: build
    runs-on: ubuntu-latest
    timeout-minutes: 60
    strategy:
      fail-fast: false
      matrix: ${{ fromJson(needs.gen-matrix.outputs.matrix) }}

    steps:
      - name: Get short node version
        uses: actions/github-script@v3
        id: short-version
        with:
          result-encoding: string
          script: return "${{ matrix.version }}".split('.')[0]

      - name: Checkout
        uses: actions/checkout@v2

      - name: Build image
        uses: docker/build-push-action@v2
        with:
          push: false
          load: true
          context: .
          file: ./${{ steps.short-version.outputs.result }}/${{ matrix.variant }}/Dockerfile
          tags: node:${{ matrix.version }}-${{ matrix.variant }}

      - name: Test for node version
        run: |
          image_node_version=$(docker run --rm node:${{ matrix.version }}-${{ matrix.variant }} node --print "process.versions.node")
          echo "Expected: \"${{ matrix.version }}\", Got: \"${image_node_version}\""
          [ "${image_node_version}" == "${{ matrix.version }}" ]

      - name: Test for npm
        run: docker run --rm node:${{ matrix.version }}-${{ matrix.variant }} npm --version

      - name: Test for yarn
        run: docker run --rm node:${{ matrix.version }}-${{ matrix.variant }} yarn --version