GitHub Workflow to cache node_modules and run Jest.

github_test_ci_workflow.yml

name: Test

on: [push]

jobs:
  test:
    runs-on: ubuntu-latest

    strategy:
      matrix:
        node-version: [12.16.1]

    steps:
      - uses: actions/checkout@v2

      - name: Use Node.js ${{ matrix.node-version }}
        uses: actions/setup-node@v1
        with:
          node-version: ${{ matrix.node-version }}

      - name: Get yarn cache directory path
        id: yarn-cache-dir-path
        run: echo "::set-output name=dir::$(yarn cache dir)"

      - name: Cache Node modules
        id: yarn-cache # use this to check for `cache-hit` (`steps.yarn-cache.outputs.cache-hit != 'true'`)
        uses: actions/cache@v1
        env:
          cache-name: cache-node-modules
        with:
          path: ${{ steps.yarn-cache-dir-path.outputs.dir }}
          key: ${{ runner.os }}-yarn-${{ env.cache-name }}-${{ hashFiles('**/yarn.lock') }}
          restore-keys: |
            ${{ runner.os }}-yarn-${{ env.cache-name }}-
            ${{ runner.os }}-yarn-
            ${{ runner.os }}-

      - name: Install Dependencies
        run: |
          echo "node version: $(node --version)"
          echo "npm version: $(npm --version)"
          echo CI=$CI
          yarn install --frozen-lockfile

      - name: Test App
        run: |
          echo CI=$CI
          yarn test
        env:
          CI: true # default: true - causes warnings during build to fail the build.