Add linter for web folder

test.sh

@@ -39,6 +39,10 @@ fi
 echo "=== Installing web dependencies ==="
 cd "$SCRIPT_DIR/web" && npm install
 
+echo ""
+echo "=== Linting ==="
+cd "$SCRIPT_DIR/web" && npx eslint .
+
 echo ""
 echo "=== Building web app ==="
 cd "$SCRIPT_DIR/web" && node build.mjs

web/eslint.config.mjs

@@ -0,0 +1,55 @@
+export default [
+    {
+        files: ['src/**/*.js'],
+        ignores: ['src/js/wasm_exec.js'],
+        languageOptions: {
+            ecmaVersion: 2022,
+            sourceType: 'module',
+            globals: {
+                // Browser globals
+                window: 'readonly',
+                document: 'readonly',
+                console: 'readonly',
+                fetch: 'readonly',
+                URL: 'readonly',
+                Blob: 'readonly',
+                Uint8Array: 'readonly',
+                TextEncoder: 'readonly',
+                TextDecoder: 'readonly',
+                Event: 'readonly',
+                DOMException: 'readonly',
+                HTMLElement: 'readonly',
+                Worker: 'readonly',
+                requestAnimationFrame: 'readonly',
+                // JSZip loaded via script tag
+                JSZip: 'readonly',
+            },
+        },
+        rules: {
+            'no-unused-vars': ['warn', { argsIgnorePattern: '^_' }],
+            'no-undef': 'error',
+            'no-constant-condition': 'warn',
+            'eqeqeq': ['error', 'always'],
+            'no-var': 'error',
+            'prefer-const': 'warn',
+        },
+    },
+    {
+        // Worker script uses importScripts, self, Go, globalThis, WebAssembly
+        files: ['src/js/patch-worker.js'],
+        languageOptions: {
+            globals: {
+                self: 'readonly',
+                importScripts: 'readonly',
+                Go: 'readonly',
+                globalThis: 'readonly',
+                WebAssembly: 'readonly',
+                fetch: 'readonly',
+                console: 'readonly',
+            },
+        },
+    },
+    {
+        ignores: ['src/js/wasm_exec.js', 'dist/**', 'node_modules/**'],
+    },
+];

web/package.json

@@ -3,10 +3,12 @@
   "private": true,
   "scripts": {
     "build": "node build.mjs",
-    "dev": "node build.mjs --dev"
+    "dev": "node build.mjs --dev",
+    "lint": "eslint ."
   },
   "devDependencies": {
-    "esbuild": "^0.27.4"
+    "esbuild": "^0.27.4",
+    "eslint": "^9.0.0"
   },
   "dependencies": {
     "jszip": "^3.10.1"

web/src/js/app.js

@@ -36,7 +36,7 @@ import JSZip from 'jszip';
 
     // Check KOReader availability and mark the feature (best-effort, non-blocking).
     const koreaderFeature = ALL_FEATURES.find(f => f.id === 'koreader');
-    const koreaderVersionReady = fetch('/koreader/release.json')
+    const koreaderVersionReady = fetch('/koreader/release.json') // eslint-disable-line no-unused-vars -- fire-and-forget; availability resolves before user reaches features step
         .then(r => r.ok ? r.json() : null)
         .then(meta => {
             if (meta && meta.version) {
@@ -148,7 +148,7 @@ import JSZip from 'jszip';
 
     // --- Step navigation ---
 
-    let currentNavLabels = TL.NAV_DEFAULT;
+    let currentNavLabels = TL.NAV_DEFAULT; // eslint-disable-line no-unused-vars -- kept for debuggability; tracks which label set is active
 
     const stepHistory = [stepConnect];