Creating test suite for js/themebox.js (#4377)

Author: omsuneri

js/__tests__/themebox.test.js

@@ -0,0 +1,62 @@
+global._ = jest.fn((str) => str); 
+const ThemeBox = require("../themebox");
+
+describe("ThemeBox", () => {
+    let mockActivity;
+    let themeBox;
+
+    beforeEach(() => {
+        mockActivity = {
+            storage: {
+                themePreference: "light"
+            },
+            textMsg: jest.fn()
+        };
+
+        jest.spyOn(global.Storage.prototype, "getItem").mockImplementation((key) => {
+            return key === "themePreference" ? "light" : null;
+        });
+        jest.spyOn(global.Storage.prototype, "setItem").mockImplementation(() => {});
+
+        Object.defineProperty(window, "location", {
+            value: { reload: jest.fn() },
+            writable: true,
+        });
+
+        themeBox = new ThemeBox(mockActivity);
+    });
+
+    afterEach(() => {
+        jest.restoreAllMocks();
+    });
+
+    test("constructor initializes theme from activity storage", () => {
+        expect(themeBox._theme).toBe("light");
+    });
+
+    test("light_onclick() sets theme to light and updates preference", () => {
+        themeBox.light_onclick();
+        expect(themeBox._theme).toBe("light");
+        expect(localStorage.getItem).toHaveBeenCalledWith("themePreference");
+        expect(mockActivity.textMsg).toHaveBeenCalledWith("Music Blocks is already set to this theme.");
+    });
+
+    test("dark_onclick() sets theme to dark and updates preference", () => {
+        themeBox.dark_onclick();
+        expect(themeBox._theme).toBe("dark");
+        expect(mockActivity.storage.themePreference).toBe("dark");
+        expect(window.location.reload).toHaveBeenCalled();
+    });
+
+    test("setPreference() updates theme and reloads if different", () => {
+        localStorage.getItem.mockReturnValue("dark"); // Correctly mocked now
+        themeBox.light_onclick();
+        expect(mockActivity.storage.themePreference).toBe("light");
+        expect(window.location.reload).toHaveBeenCalled();
+    });
+
+    test("setPreference() does not reload if theme is unchanged", () => {
+        themeBox.light_onclick();
+        expect(window.location.reload).not.toHaveBeenCalled();
+    });
+});