Improved eslint config as proposed in #61

.eslintrc.js

@@ -2,11 +2,27 @@
 
 "use strict";
 
-/* All Mozilla specific rules and enviroments at:
- * http://firefox-source-docs.mozilla.org/tools/lint/linters/eslint-plugin-mozilla.html
- */
+// All Mozilla specific rules and environments at:
+// http://firefox-source-docs.mozilla.org/tools/lint/linters/eslint-plugin-mozilla.html
 
 module.exports = {
+  env: {
+    es6: true,
+  },
+  extends: [
+    "eslint:recommended",
+    // list of rules at: https://dxr.mozilla.org/mozilla-central/source/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/recommended.js
+    "plugin:mozilla/recommended",
+  ],
+  overrides: [
+    {
+      files: "src/**",
+      env: {
+        browser: true,
+        webextensions: true,
+      },
+    },
+  ],
   parserOptions: {
     ecmaVersion: 8,
     sourceType: "module",
@@ -15,31 +31,25 @@ module.exports = {
       experimentalObjectRestSpread: true,
     },
   },
-  env: {
-    es6: true,
-  },
-  extends: [
-    "eslint:recommended",
-    /* list of rules at:
-     * https://dxr.mozilla.org/mozilla-central/source/tools/lint/eslint/eslint-plugin-mozilla/lib/configs/recommended.js
-     */
-    "plugin:mozilla/recommended",
+  plugins: [
+    "json",
+    "mozilla",
   ],
-
-  plugins: ["json", "mozilla"],
-
+  root: true,
   rules: {
     "babel/new-cap": "off",
-    "comma-dangle": ["error", "always-multiline"],
-    eqeqeq: "error",
-    indent: ["warn", 2, { SwitchCase: 1 }],
     "mozilla/no-aArgs": "warn",
     "mozilla/balanced-listeners": "off",
+    "comma-dangle": ["error", "always-multiline"],
+    "eqeqeq": "error",
+    "indent": ["warn", 2, { SwitchCase: 1 }],
     "no-console": "warn",
+    "no-var": "error",
     "no-shadow": "error",
     "no-unused-vars": "error",
     "prefer-const": "warn",
     "prefer-spread": "error",
-    semi: ["error", "always"],
+    "semi": ["error", "always"],
+    "valid-jsdoc": "warn",
   },
 };