set up ESLint

Author: mockdeep

.gitignore

@@ -29,3 +29,6 @@ spec/examples.txt
 # Ignore local .env files
 *.local
 .env
+
+# Node
+/node_modules

app/assets/javascripts/application.js

@@ -7,7 +7,7 @@
 //= require backbone-min.js
 
 _.templateSettings = {
-  interpolate: /\{\{\=(.+?)\}\}/g,
+  interpolate: /\{\{=(.+?)\}\}/g,
   evaluate: /\{\{(.+?)\}\}/g
 };
 

eslint.config.mjs

@@ -0,0 +1,45 @@
+import js from "@eslint/js";
+import globals from "globals";
+
+export default [
+  js.configs.recommended,
+  {
+    languageOptions: {
+      sourceType: "script",
+      globals: {
+        ...globals.browser,
+        Backbone: "readonly",
+        _: "readonly",
+        $: "readonly",
+        jQuery: "readonly",
+        Mousetrap: "readonly",
+      },
+    },
+    rules: {
+      "no-var": "off",
+      "no-unused-vars": "warn",
+    },
+  },
+  {
+    files: ["spec/javascript/spec/**"],
+    languageOptions: {
+      globals: {
+        describe: "readonly",
+        it: "readonly",
+        before: "readonly",
+        beforeEach: "readonly",
+        afterEach: "readonly",
+        sinon: "readonly",
+        chai: "readonly",
+        mocha: "readonly",
+        initMochaPhantomJS: "readonly",
+        Story: "readonly",
+        StoryView: "readonly",
+        StoryList: "readonly",
+      },
+    },
+  },
+  {
+    ignores: ["vendor/", "coverage/", "spec/javascript/support/", "public/"],
+  },
+];

package.json

@@ -0,0 +1,12 @@
+{
+  "private": true,
+  "scripts": {
+    "lint": "eslint app/assets/javascripts/ spec/javascript/spec/"
+  },
+  "devDependencies": {
+    "@eslint/js": "^9.21.0",
+    "eslint": "^9.21.0",
+    "globals": "^16.0.0"
+  },
+  "packageManager": "pnpm@10.4.1"
+}