diff --git a/package.json b/package.json
index 0d02693..c1b3cec 100644
--- a/package.json
+++ b/package.json
@@ -1,13 +1,15 @@
 {
   "name": "food-journal",
   "version": "1.0.0",
+  "type": "module",
   "scripts": {
-    "test": "mocha --recursive './{,!(node_modules)/**}/*.test.js'",
+    "test": "mocha --recursive --require mock-local-storage './{,!(node_modules)/**}/*.test.js'",
     "lint": "eslint **/*.js",
     "fix-style": "eslint --fix '**/*.js'"
   },
   "devDependencies": {
     "eslint": "^8.27.0",
-    "mocha": "10"
+    "mocha": "10",
+    "mock-local-storage": "^1.1.23"
   }
 }
diff --git a/source/assets/scripts/localStorage.js b/source/assets/scripts/localStorage.js
index 7495993..29a72ce 100644
--- a/source/assets/scripts/localStorage.js
+++ b/source/assets/scripts/localStorage.js
@@ -1,6 +1,3 @@
-//
-//module.exports = {getReviewsFromStorage, saveReviewsToStorage};
-
 /**
  * @returns {Array<Object>} An array of reviews found in localStorage
  */
diff --git a/source/assets/scripts/localStorage.test.js b/source/assets/scripts/localStorage.test.js
index ae9554b..ed11bb5 100644
--- a/source/assets/scripts/localStorage.test.js
+++ b/source/assets/scripts/localStorage.test.js
@@ -1,11 +1,9 @@
-const {getReviewsFromStorage, saveReviewsToStorage} = require("./localStorage");
-const {environment} = require("./testenv");
-const assert = require("assert");
-const {describe, it, beforeEach} = require("mocha");
+import {strict as assert} from "node:assert"
+import {describe, it, beforeEach} from "mocha";
+import {saveReviewsToStorage, getReviewsFromStorage} from "./localStorage.js";
 
 beforeEach(() => {
-	window = environment();
-	localStorage = window.localStorage;
+	localStorage.clear();
 });
 
 describe("test app localStorage interaction", () => {
@@ -26,7 +24,8 @@ describe("test app localStorage interaction", () => {
 		assert.deepEqual(getReviewsFromStorage(), reviews);
 	});
 	it("repeated store one more and get", () => {
-		saveReviewsToStorage(reviews);
+		let reviews = [];
+
 		assert.deepEqual(getReviewsFromStorage(), reviews);
 
 		for(let i = 0; i < 1000; i++){
diff --git a/source/assets/scripts/testenv.js b/source/assets/scripts/testenv.js
deleted file mode 100644
index 01b6e4c..0000000
--- a/source/assets/scripts/testenv.js
+++ /dev/null
@@ -1,28 +0,0 @@
-module.exports = {environment};
-
-function environment () {
-	const localStorageMock = (function () {
-		let store = {};
-		return {
-			getItem(key) {
-				return store[key];
-			},
-			setItem(key, value) {
-				store[key] = value;
-			},
-			clear() {
-				store = {};
-			},
-			removeItem(key) {
-				delete store[key];
-			},
-			getAll() {
-				return store;
-			},
-		};
-	})();
-
-	let window = {};
-	Object.defineProperty(window, "localStorage", { value: localStorageMock });
-	return window;
-}
\ No newline at end of file
diff --git a/testenv/testenv.js b/testenv/testenv.js
deleted file mode 100644
index 01b6e4c..0000000
--- a/testenv/testenv.js
+++ /dev/null
@@ -1,28 +0,0 @@
-module.exports = {environment};
-
-function environment () {
-	const localStorageMock = (function () {
-		let store = {};
-		return {
-			getItem(key) {
-				return store[key];
-			},
-			setItem(key, value) {
-				store[key] = value;
-			},
-			clear() {
-				store = {};
-			},
-			removeItem(key) {
-				delete store[key];
-			},
-			getAll() {
-				return store;
-			},
-		};
-	})();
-
-	let window = {};
-	Object.defineProperty(window, "localStorage", { value: localStorageMock });
-	return window;
-}
\ No newline at end of file
diff --git a/testenv/testenv.test.js b/testenv/testenv.test.js
deleted file mode 100644
index 91bf30b..0000000
--- a/testenv/testenv.test.js
+++ /dev/null
@@ -1,81 +0,0 @@
-const {environment} = require("./testenv.js");
-var assert = require("assert");
-var {describe, it, beforeEach} = require("mocha");
-var {saveToLocal, getFromLocal, removeFromLocal, clearLocal} = require("./testenv_helpers");
-
-beforeEach(() => {
-	window = environment();
-});
-
-describe("test localStorage mock", () => {
-	it("test save and fetch", () => {
-		saveToLocal("testkey1", "testvalue1");
-		saveToLocal("testkey2", "testvalue2");
-		saveToLocal("testkey3", "testvalue3");
-		saveToLocal("testkey4", "testvalue4");
-
-		assert.equal(getFromLocal("testkey1"), "testvalue1");
-		assert.equal(getFromLocal("testkey2"), "testvalue2");
-		assert.equal(getFromLocal("testkey3"), "testvalue3");
-		assert.equal(getFromLocal("testkey4"), "testvalue4");
-
-		saveToLocal("testkey6", "testvalue5");
-		assert.equal(getFromLocal("testkey6"), "testvalue5");
-	});
-
-	it("test window locality", () => {
-		assert.equal(getFromLocal("testkey1"), null);
-		assert.equal(getFromLocal("testkey2"), null);
-		assert.equal(getFromLocal("testkey3"), null);
-		assert.equal(getFromLocal("testkey4"), null);
-	});
-
-	it("test delete and fetch", () => {
-		saveToLocal("testkey1", "testvalue1");
-		saveToLocal("testkey2", "testvalue2");
-		saveToLocal("testkey3", "testvalue3");
-		saveToLocal("testkey4", "testvalue4");
-
-		removeFromLocal("testkey3");
-
-		assert.equal(getFromLocal("testkey1"), "testvalue1");
-		assert.equal(getFromLocal("testkey2"), "testvalue2");
-		assert.equal(getFromLocal("testkey3"), null);
-		assert.equal(getFromLocal("testkey4"), "testvalue4");
-
-		removeFromLocal("testkey1");
-
-		assert.equal(getFromLocal("testkey1"), null);
-		assert.equal(getFromLocal("testkey2"), "testvalue2");
-		assert.equal(getFromLocal("testkey3"), null);
-		assert.equal(getFromLocal("testkey4"), "testvalue4");
-
-		removeFromLocal("testkey4");
-		
-		assert.equal(getFromLocal("testkey1"), null);
-		assert.equal(getFromLocal("testkey2"), "testvalue2");
-		assert.equal(getFromLocal("testkey3"), null);
-		assert.equal(getFromLocal("testkey4"), null);
-
-		removeFromLocal("testkey2");
-		
-		assert.equal(getFromLocal("testkey1"), null);
-		assert.equal(getFromLocal("testkey2"), null);
-		assert.equal(getFromLocal("testkey3"), null);
-		assert.equal(getFromLocal("testkey4"), null);
-	});
-
-	it("test clear and fetch", () => {
-		saveToLocal("testkey1", "testvalue1");
-		saveToLocal("testkey2", "testvalue2");
-		saveToLocal("testkey3", "testvalue3");
-		saveToLocal("testkey4", "testvalue4");
-
-		clearLocal();
-
-		assert.equal(getFromLocal("testkey1"), null);
-		assert.equal(getFromLocal("testkey2"), null);
-		assert.equal(getFromLocal("testkey3"), null);
-		assert.equal(getFromLocal("testkey4"), null);
-	});
-});
\ No newline at end of file
diff --git a/testenv/testenv_helpers.js b/testenv/testenv_helpers.js
deleted file mode 100644
index 469adc5..0000000
--- a/testenv/testenv_helpers.js
+++ /dev/null
@@ -1,17 +0,0 @@
-module.exports = {saveToLocal, getFromLocal, removeFromLocal, clearLocal};
-
-function saveToLocal (k, v) {
-	window.localStorage.setItem(k, v);
-}
-
-function getFromLocal (k) {
-	return window.localStorage.getItem(k);
-}
-
-function removeFromLocal (k) {
-	window.localStorage.removeItem(k);
-}
-
-function clearLocal () {
-	window.localStorage.clear();
-} 
\ No newline at end of file