switch unit test framework to jest,

remove framework unittest,
add helper module to create unit testing environment

testenv/package.json

@@ -0,0 +1,10 @@
+{
+  "name": "testenv",
+  "version": "1.0.0",
+  "scripts": {
+    "test": "jest"
+  },
+  "dependencies": {
+    "jest": "24"
+  }
+}

testenv/testenv.js

@@ -0,0 +1,28 @@
+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;
+}

testenv/testenv.test.js

@@ -0,0 +1,86 @@
+const {environment} = require("./testenv.js");
+
+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();
+} 
+
+describe("test localStorage mock", () => {
+	test("test save and fetch", () => {
+		let window = environment();
+		saveToLocal("testkey1", "testvalue1");
+		saveToLocal("testkey2", "testvalue2");
+		saveToLocal("testkey3", "testvalue3");
+		saveToLocal("testkey4", "testvalue4");
+
+		expect(getFromLocal("testkey1")).toBe("testvalue1");
+		expect(getFromLocal("testkey2")).toBe("testvalue2");
+		expect(getFromLocal("testkey3")).toBe("testvalue3");
+		expect(getFromLocal("testkey4")).toBe("testvalue4");
+
+		saveToLocal("testkey6", "testvalue5");
+		expect(getFromLocal("testkey6")).toBe("testvalue5");
+	});
+
+	test("test delete and fetch", () => {
+		let window = environment();
+		saveToLocal("testkey1", "testvalue1");
+		saveToLocal("testkey2", "testvalue2");
+		saveToLocal("testkey3", "testvalue3");
+		saveToLocal("testkey4", "testvalue4");
+
+		removeFromLocal("testkey3");
+
+		expect(getFromLocal("testkey1")).toBe("testvalue1");
+		expect(getFromLocal("testkey2")).toBe("testvalue2");
+		expect(getFromLocal("testkey3")).toBe(null);
+		expect(getFromLocal("testkey4")).toBe("testvalue4");
+
+		removeFromLocal("testkey1");
+
+		expect(getFromLocal("testkey1")).toBe(null);
+		expect(getFromLocal("testkey2")).toBe("testvalue2");
+		expect(getFromLocal("testkey3")).toBe(null);
+		expect(getFromLocal("testkey4")).toBe("testvalue4");
+
+		removeFromLocal("testkey4");
+		
+		expect(getFromLocal("testkey1")).toBe(null);
+		expect(getFromLocal("testkey2")).toBe("testvalue2");
+		expect(getFromLocal("testkey3")).toBe(null);
+		expect(getFromLocal("testkey4")).toBe(null);
+
+		removeFromLocal("testkey2");
+		
+		expect(getFromLocal("testkey1")).toBe(null);
+		expect(getFromLocal("testkey2")).toBe(null);
+		expect(getFromLocal("testkey3")).toBe(null);
+		expect(getFromLocal("testkey4")).toBe(null);
+	});
+
+	test("test delete and fetch", () => {
+		let window = environment();
+		saveToLocal("testkey1", "testvalue1");
+		saveToLocal("testkey2", "testvalue2");
+		saveToLocal("testkey3", "testvalue3");
+		saveToLocal("testkey4", "testvalue4");
+
+		clearLocal();
+
+		expect(getFromLocal("testkey1")).toBe(null);
+		expect(getFromLocal("testkey2")).toBe(null);
+		expect(getFromLocal("testkey3")).toBe(null);
+		expect(getFromLocal("testkey4")).toBe(null);
+	});
+});