set up eslint and address some linting errors. add unix-mount test.

eslint.config.mjs

@@ -0,0 +1,9 @@
+import ts_eslint from "typescript-eslint";
+
+/** @type {import('eslint').Linter.Config[]} */
+export default [
+  {
+    files: ["src/**/*.ts}"],
+  },
+  ...ts_eslint.configs.recommended,
+];

package.json

@@ -16,8 +16,8 @@
     "test:coverage": "jest --coverage",
     "test:clear": "jest --clearCache",
     "test:debug": "node --inspect-brk jest --runInBand",
-    "lint": "eslint . --ext .ts",
-    "lint:fix": "eslint . --ext .ts --fix",
+    "lint": "eslint",
+    "lint:fix": "eslint --fix",
     "fmt": "prettier --write \"src/**/*.ts\" && npm run fmt:cpp",
     "fmt:cpp": "clang-format --style=LLVM -i src/*/*.cpp src/*/*.h"
   },
@@ -36,19 +36,20 @@
     "node-addon-api": "^8.2.2"
   },
   "devDependencies": {
+    "@eslint/js": "^9.14.0",
     "@types/jest": "^29.5.14",
     "@types/node": "^22.9.0",
     "@typescript-eslint/eslint-plugin": "^8.13.0",
     "@typescript-eslint/parser": "^8.13.0",
-    "eslint-config-prettier": "^9.1.0",
-    "eslint-plugin-prettier": "^5.2.1",
     "eslint": "^9.14.0",
+    "globals": "^15.12.0",
     "jest": "^29.7.0",
     "node-gyp": "^10.2.0",
-    "prettier-plugin-organize-imports": "4.1.0",
     "prettier": "^3.3.3",
+    "prettier-plugin-organize-imports": "4.1.0",
     "ts-jest": "^29.2.5",
     "typedoc": "^0.26.11",
-    "typescript": "^5.6.3"
+    "typescript": "^5.6.3",
+    "typescript-eslint": "^8.13.0"
   }
 }

src/DeepFreeze.ts

@@ -2,27 +2,46 @@
 
 export type DeepReadonly<T> = T extends (infer R)[]
   ? ReadonlyArray<DeepReadonly<R>>
+  // eslint-disable-next-line @typescript-eslint/no-unsafe-function-type
   : T extends Function
-    ? T
+    ? T 
     : T extends object
       ? { readonly [P in keyof T]: DeepReadonly<T[P]> }
       : T;
 
 export type OrDeepReadonly<T> = T | DeepReadonly<T>;
 
+/**
+ * Type guard to check if a value is an object (excluding null and arrays)
+ */
+function isObject(value: unknown): value is Record<string | symbol | number, unknown> {
+  return typeof value === 'object' && value !== null && !Array.isArray(value);
+}
+
 /**
  * Recursively freezes an object and all of its properties
  */
 export function deepFreeze<T>(obj: T): DeepReadonly<T> {
-  if (obj == null || typeof obj !== "object" || Object.isFrozen(obj)) {
-    return obj as any;
+  // Handle primitive types and frozen objects
+  if (obj === null || typeof obj !== 'object' || Object.isFrozen(obj)) {
+    return obj as DeepReadonly<T>;
   }
+
   if (Array.isArray(obj)) {
-    return Object.freeze(obj.map(deepFreeze)) as any;
+    const frozenArray = Object.freeze(obj.map(deepFreeze)) as ReadonlyArray<DeepReadonly<T extends (infer U)[] ? U : never>>;
+    return frozenArray as DeepReadonly<T>;
   }
-  const result = {} as any;
-  for (const [key, value] of Object.entries(obj)) {
-    result[key] = deepFreeze(value);
+
+  if (isObject(obj)) {
+    const result = {} as T;
+
+    Object.entries(obj as Record<string, unknown>).forEach(([key, value]) => {
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      (result as any)[key] = deepFreeze(value);
+    });
+
+    return Object.freeze(result) as DeepReadonly<T>;
   }
-  return Object.freeze(result);
-}
+
+  return obj as DeepReadonly<T>;
+}

src/__tests__/async-behavior.test.ts

@@ -5,10 +5,9 @@ import { describePlatform } from "../test-utils/platform";
 
 describe("Filesystem API Async Behavior", () => {
   const describeLinux = describePlatform("linux");
-  const describeWindows = describePlatform("win32");
 
   // Helper to measure execution time
-  const timeExecution = async (fn: () => Promise<any>): Promise<number> => {
+  const timeExecution = async (fn: () => Promise<unknown>): Promise<number> => {
     const start = process.hrtime();
     await fn();
     const [seconds, nanoseconds] = process.hrtime(start);