Add eslint for server

eslint.config.mjs

@@ -0,0 +1,59 @@
+const nodeGlobals = {
+  AbortController: 'readonly',
+  Buffer: 'readonly',
+  TextDecoder: 'readonly',
+  URL: 'readonly',
+  URLSearchParams: 'readonly',
+  __dirname: 'readonly',
+  clearInterval: 'readonly',
+  clearTimeout: 'readonly',
+  console: 'readonly',
+  process: 'readonly',
+  setInterval: 'readonly',
+  setTimeout: 'readonly',
+  structuredClone: 'readonly'
+}
+
+const mochaGlobals = {
+  after: 'readonly',
+  afterEach: 'readonly',
+  before: 'readonly',
+  beforeEach: 'readonly',
+  describe: 'readonly',
+  it: 'readonly'
+}
+
+const rules = {
+  'no-undef': 'error',
+  'no-redeclare': 'error',
+  'no-dupe-keys': 'error',
+  'no-dupe-class-members': 'error',
+  'no-global-assign': 'error'
+}
+
+export default [
+  {
+    ignores: ['**/node_modules/**', 'client/**', 'dist/**', 'dist-server/**', 'coverage/**', 'server/libs/**']
+  },
+  {
+    files: ['index.js', 'prod.js', 'dev.js', 'server/**/*.js'],
+    languageOptions: {
+      ecmaVersion: 'latest',
+      sourceType: 'commonjs',
+      globals: nodeGlobals
+    },
+    rules
+  },
+  {
+    files: ['test/**/*.js'],
+    languageOptions: {
+      ecmaVersion: 'latest',
+      sourceType: 'commonjs',
+      globals: {
+        ...nodeGlobals,
+        ...mochaGlobals
+      }
+    },
+    rules
+  }
+]

package.json

@@ -19,7 +19,8 @@
     "docker-arm64-local": "docker buildx build --platform linux/arm64 --load .  -t advplyr/audiobookshelf-arm64-local",
     "deploy-linux": "node deploy/linux",
     "test": "npm run build:server && mocha dist-server/test",
-    "coverage": "npm run build:server && nyc mocha dist-server/test"
+    "coverage": "npm run build:server && nyc mocha dist-server/test",
+    "lint": "eslint ."
   },
   "bin": "dist-server/index.js",
   "pkg": {
@@ -63,6 +64,7 @@
   "devDependencies": {
     "@types/node": "^20.17.0",
     "chai": "^4.3.10",
+    "eslint": "^10.11.0",
     "mocha": "^10.2.0",
     "nodemon": "^2.0.20",
     "nyc": "^15.1.0",