feat: add UI toast notification for missing Firefox browser

test/unit/toastNotifier.test.js

@@ -0,0 +1,38 @@
+const mockSend = jest.fn();
+const mockGetMainWindow = jest.fn();
+
+jest.mock("../../app/windowManager", () => ({
+    getMainWindow: mockGetMainWindow,
+}));
+
+const {sendToast} = require("../../app/toastNotifier");
+
+describe("toastNotifier", () => {
+    beforeEach(() => {
+        jest.clearAllMocks();
+    });
+
+    test("sends a toast to the active renderer", () => {
+        mockGetMainWindow.mockReturnValue({
+            isDestroyed: () => false,
+            webContents: {
+                isDestroyed: () => false,
+                send: mockSend,
+            },
+        });
+
+        expect(sendToast("Firefox is missing", "error", 5000)).toBe(true);
+        expect(mockSend).toHaveBeenCalledWith("show-toast", {
+            message: "Firefox is missing",
+            type: "error",
+            duration: 5000,
+        });
+    });
+
+    test("does not throw when the renderer is unavailable", () => {
+        mockGetMainWindow.mockReturnValue(null);
+
+        expect(sendToast("Firefox is missing", "error")).toBe(false);
+        expect(mockSend).not.toHaveBeenCalled();
+    });
+});