add lint

.eslintrc.js

@@ -0,0 +1,18 @@
+
+// TODO: also check .d.ts files
+module.exports = {
+    ignorePatterns: ['applications/*'],
+    env: {
+        commonjs: true,
+        es2021: true,
+        node: true,
+        browser: true
+    },
+    parserOptions: {
+        ecmaVersion: 12,
+        sourceType: 'module'
+    },
+    rules: {
+        'max-len': [2, 120]
+    }
+};

.github/workflows/node.js.yml

@@ -10,10 +10,19 @@ on:
     branches: [ main ]
 
 jobs:
-  build:
-
+  lint:
     runs-on: ubuntu-latest
+    - uses: actions/checkout@v2
+    - name: Use Node.js 16
+    uses: actions/setup-node@v2
+    with:
+      node-version: 16
+      cache: 'npm'
+    - run: npm ci
+    - run: npm run lint
 
+  test:
+    runs-on: ubuntu-latest
     strategy:
       matrix:
         node-version: [12.x, 14.x, 16.x]