Used GitHub actions for JavaScript tests.

.editorconfig

@@ -42,3 +42,6 @@ indent_style = tab
 
 [docs/**.txt]
 max_line_length = 79
+
+[*.yml]
+indent_size = 2

.github/workflows/tests.yml

@@ -0,0 +1,25 @@
+name: Tests
+
+on:
+  pull_request:
+
+jobs:
+  javascript-tests:
+    runs-on: ubuntu-latest
+    name: JavaScript tests
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+      - name: Set up Node.js
+        uses: actions/setup-node@v2
+        with:
+          node-version: '12'
+      - name: Cache dependencies
+        uses: actions/cache@v2
+        with:
+          path: ~/.npm
+          key: ${{ runner.os }}-node-${{ hashFiles('**/package.json') }}
+          restore-keys: |
+            ${{ runner.os }}-node-
+      - run: npm install
+      - run: npm test