Add worlflow for testing

Author: hankei6km

.github/workflows/test.yaml

@@ -0,0 +1,41 @@
+# https://github.com/marketplace/actions/run-jest
+name: test
+on:
+  push:
+    branches_ignore:
+      - master
+jobs:
+
+  jest:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [14.x]
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v1
+      with:
+         node-version: ${{ matrix.node-version }}
+
+    # https://docs.github.com/ja/free-pro-team@latest/actions/guides/caching-dependencies-to-speed-up-workflows
+    - name: Cache node modules
+      uses: actions/cache@v2
+      env:
+        cache-name: cache-node-modules
+      with:
+        # npm キャッシュファイルは Linux/macOS の「~/.npm」に保存される
+        path: ~/.npm
+        key: ${{ runner.os }}-build-${{ env.cache-name }}-${{ hashFiles('**/package-lock.json') }}
+        restore-keys: |
+          ${{ runner.os }}-build-${{ env.cache-name }}-
+          ${{ runner.os }}-build-
+
+    - name: Install modules
+      run: npm install
+
+    - name: Run tests
+      run: npm run test