chore: add eslint and fix linting errors

Author: lojjic

.eslintrc.js

@@ -0,0 +1,30 @@
+module.exports = {
+  "env": {
+    "browser": true,
+    "es2021": true,
+    "jest/globals": true
+  },
+  "extends": [
+    "eslint:recommended"
+  ],
+  "globals": {
+    "process": "readonly",
+    "importScripts": "readonly"
+  },
+  "overrides": [
+  ],
+  "parserOptions": {
+    "ecmaVersion": "latest",
+    "sourceType": "module",
+    "ecmaFeatures": {
+      "jsx": true
+    }
+  },
+  "plugins": [
+    "jest"
+  ],
+  "rules": {
+    "no-prototype-builtins": 0,
+    "no-unused-vars": ["error", { "vars": "all", "args": "none" }]
+  }
+}

.github/workflows/ci.yml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        node-version: [10.x, 12.x, 14.x, 15.x]
+        node-version: [16.x]
         # See supported Node.js release schedule at https://nodejs.org/en/about/releases/
     steps:
     - uses: actions/checkout@v2
@@ -25,5 +25,6 @@ jobs:
     - run: npm ci
     - run: npm run build
     - run: npm test
+    - run: npm run lint
     - run: npm run build-examples