test(web): update tasks page tests for real API integration (#475)

Co-authored-by: Jason Woltje <jason@diversecanvas.com>
Co-committed-by: Jason Woltje <jason@diversecanvas.com>

apps/web/src/app/(authenticated)/tasks/page.test.tsx

@@ -1,5 +1,8 @@
-import { describe, it, expect, vi } from "vitest";
+import { describe, it, expect, vi, beforeEach } from "vitest";
 import { render, screen, waitFor } from "@testing-library/react";
+import userEvent from "@testing-library/user-event";
+import type { Task } from "@mosaic/shared";
+import { TaskStatus, TaskPriority } from "@mosaic/shared";
 import TasksPage from "./page";
 
 // Mock the TaskList component
@@ -9,21 +12,121 @@ vi.mock("@/components/tasks/TaskList", () => ({
   ),
 }));
 
+// Mock MosaicSpinner
+vi.mock("@/components/ui/MosaicSpinner", () => ({
+  MosaicSpinner: ({ label }: { label?: string }): React.JSX.Element => (
+    <div data-testid="mosaic-spinner">{label ?? "Loading..."}</div>
+  ),
+}));
+
+// Mock useWorkspaceId
+const mockUseWorkspaceId = vi.fn<() => string | null>();
+vi.mock("@/lib/hooks", () => ({
+  useWorkspaceId: (): string | null => mockUseWorkspaceId(),
+}));
+
+// Mock fetchTasks
+const mockFetchTasks = vi.fn<() => Promise<Task[]>>();
+vi.mock("@/lib/api/tasks", () => ({
+  fetchTasks: (...args: unknown[]): Promise<Task[]> => mockFetchTasks(...(args as [])),
+}));
+
+const fakeTasks: Task[] = [
+  {
+    id: "task-1",
+    title: "Test task 1",
+    description: "Description 1",
+    status: TaskStatus.IN_PROGRESS,
+    priority: TaskPriority.HIGH,
+    dueDate: new Date("2026-02-01"),
+    creatorId: "user-1",
+    assigneeId: "user-1",
+    workspaceId: "ws-1",
+    projectId: null,
+    parentId: null,
+    sortOrder: 0,
+    metadata: {},
+    completedAt: null,
+    createdAt: new Date("2026-01-28"),
+    updatedAt: new Date("2026-01-28"),
+  },
+  {
+    id: "task-2",
+    title: "Test task 2",
+    description: "Description 2",
+    status: TaskStatus.NOT_STARTED,
+    priority: TaskPriority.MEDIUM,
+    dueDate: new Date("2026-02-02"),
+    creatorId: "user-1",
+    assigneeId: "user-1",
+    workspaceId: "ws-1",
+    projectId: null,
+    parentId: null,
+    sortOrder: 1,
+    metadata: {},
+    completedAt: null,
+    createdAt: new Date("2026-01-28"),
+    updatedAt: new Date("2026-01-28"),
+  },
+];
+
 describe("TasksPage", (): void => {
+  beforeEach((): void => {
+    vi.clearAllMocks();
+    mockUseWorkspaceId.mockReturnValue("ws-1");
+    mockFetchTasks.mockResolvedValue(fakeTasks);
+  });
+
   it("should render the page title", (): void => {
     render(<TasksPage />);
     expect(screen.getByRole("heading", { level: 1 })).toHaveTextContent("Tasks");
   });
 
-  it("should show loading state initially", (): void => {
+  it("should show loading spinner initially", (): void => {
+    // Never resolve so we stay in loading state
+    // eslint-disable-next-line @typescript-eslint/no-empty-function
+    mockFetchTasks.mockReturnValue(new Promise<Task[]>(() => {}));
     render(<TasksPage />);
-    expect(screen.getByTestId("task-list")).toHaveTextContent("Loading");
+    expect(screen.getByTestId("mosaic-spinner")).toBeInTheDocument();
   });
 
   it("should render the TaskList with tasks after loading", async (): Promise<void> => {
     render(<TasksPage />);
     await waitFor((): void => {
-      expect(screen.getByTestId("task-list")).toHaveTextContent("4 tasks");
+      expect(screen.getByTestId("task-list")).toHaveTextContent("2 tasks");
+    });
+  });
+
+  it("should show empty state when no tasks exist", async (): Promise<void> => {
+    mockFetchTasks.mockResolvedValue([]);
+    render(<TasksPage />);
+    await waitFor((): void => {
+      expect(screen.getByText("No tasks found")).toBeInTheDocument();
+    });
+  });
+
+  it("should show error state on API failure", async (): Promise<void> => {
+    mockFetchTasks.mockRejectedValue(new Error("Network error"));
+    render(<TasksPage />);
+    await waitFor((): void => {
+      expect(screen.getByText("Network error")).toBeInTheDocument();
+    });
+    expect(screen.getByRole("button", { name: /try again/i })).toBeInTheDocument();
+  });
+
+  it("should retry fetching on retry button click", async (): Promise<void> => {
+    mockFetchTasks.mockRejectedValueOnce(new Error("Network error"));
+    render(<TasksPage />);
+    await waitFor((): void => {
+      expect(screen.getByText("Network error")).toBeInTheDocument();
+    });
+
+    mockFetchTasks.mockResolvedValueOnce(fakeTasks);
+    const user = userEvent.setup();
+    await user.click(screen.getByRole("button", { name: /try again/i }));
+
+    await waitFor((): void => {
+      expect(screen.getByTestId("task-list")).toHaveTextContent("2 tasks");
     });
   });
 
@@ -37,4 +140,14 @@ describe("TasksPage", (): void => {
     render(<TasksPage />);
     expect(screen.getByText("Organize your work at your own pace")).toBeInTheDocument();
   });
+
+  it("should not fetch when workspace ID is not available", async (): Promise<void> => {
+    mockUseWorkspaceId.mockReturnValue(null);
+    render(<TasksPage />);
+
+    // Wait a tick to ensure useEffect ran
+    await waitFor((): void => {
+      expect(mockFetchTasks).not.toHaveBeenCalled();
+    });
+  });
 });