feat(client): add create deck modal with form validation

Add CreateDeckModal component that allows users to create new decks
with name and optional description fields. Integrates with HomePage
via a "Create Deck" button that opens the modal, and refreshes the
deck list after successful creation.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

1 files changed, 401 insertions, 0 deletions

diff --git a/src/client/components/CreateDeckModal.test.tsx b/src/client/components/CreateDeckModal.test.tsx
new file mode 100644
index 0000000..984f6d0
--- /dev/null
+++ b/src/client/components/CreateDeckModal.test.tsx
@@ -0,0 +1,401 @@
+/**
+ * @vitest-environment jsdom
+ */
+import { cleanup, render, screen, waitFor } from "@testing-library/react";
+import userEvent from "@testing-library/user-event";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+import { apiClient } from "../api/client";
+
+vi.mock("../api/client", () => ({
+	apiClient: {
+		getAuthHeader: vi.fn(),
+		rpc: {
+			api: {
+				decks: {
+					$post: vi.fn(),
+				},
+			},
+		},
+	},
+	ApiClientError: class ApiClientError extends Error {
+		constructor(
+			message: string,
+			public status: number,
+			public code?: string,
+		) {
+			super(message);
+			this.name = "ApiClientError";
+		}
+	},
+}));
+
+// Import after mock is set up
+import { CreateDeckModal } from "./CreateDeckModal";
+
+// Helper to create mock responses
+function mockResponse(data: {
+	ok: boolean;
+	status?: number;
+	// biome-ignore lint/suspicious/noExplicitAny: Test helper needs flexible typing
+	json: () => Promise<any>;
+}) {
+	return data as unknown as Awaited<
+		ReturnType<typeof apiClient.rpc.api.decks.$post>
+	>;
+}
+
+describe("CreateDeckModal", () => {
+	const defaultProps = {
+		isOpen: true,
+		onClose: vi.fn(),
+		onDeckCreated: vi.fn(),
+	};
+
+	beforeEach(() => {
+		vi.clearAllMocks();
+		vi.mocked(apiClient.getAuthHeader).mockReturnValue({
+			Authorization: "Bearer access-token",
+		});
+	});
+
+	afterEach(() => {
+		cleanup();
+		vi.restoreAllMocks();
+	});
+
+	it("does not render when closed", () => {
+		render(<CreateDeckModal {...defaultProps} isOpen={false} />);
+
+		expect(screen.queryByRole("dialog")).toBeNull();
+	});
+
+	it("renders modal when open", () => {
+		render(<CreateDeckModal {...defaultProps} />);
+
+		expect(screen.getByRole("dialog")).toBeDefined();
+		expect(
+			screen.getByRole("heading", { name: "Create New Deck" }),
+		).toBeDefined();
+		expect(screen.getByLabelText("Name")).toBeDefined();
+		expect(screen.getByLabelText("Description (optional)")).toBeDefined();
+		expect(screen.getByRole("button", { name: "Cancel" })).toBeDefined();
+		expect(screen.getByRole("button", { name: "Create" })).toBeDefined();
+	});
+
+	it("disables create button when name is empty", () => {
+		render(<CreateDeckModal {...defaultProps} />);
+
+		const createButton = screen.getByRole("button", { name: "Create" });
+		expect(createButton).toHaveProperty("disabled", true);
+	});
+
+	it("enables create button when name has content", async () => {
+		const user = userEvent.setup();
+		render(<CreateDeckModal {...defaultProps} />);
+
+		const nameInput = screen.getByLabelText("Name");
+		await user.type(nameInput, "My Deck");
+
+		const createButton = screen.getByRole("button", { name: "Create" });
+		expect(createButton).toHaveProperty("disabled", false);
+	});
+
+	it("calls onClose when Cancel is clicked", async () => {
+		const user = userEvent.setup();
+		const onClose = vi.fn();
+		render(<CreateDeckModal {...defaultProps} onClose={onClose} />);
+
+		await user.click(screen.getByRole("button", { name: "Cancel" }));
+
+		expect(onClose).toHaveBeenCalledTimes(1);
+	});
+
+	it("calls onClose when clicking outside the modal", async () => {
+		const user = userEvent.setup();
+		const onClose = vi.fn();
+		render(<CreateDeckModal {...defaultProps} onClose={onClose} />);
+
+		// Click on the backdrop (the dialog element itself)
+		const dialog = screen.getByRole("dialog");
+		await user.click(dialog);
+
+		expect(onClose).toHaveBeenCalledTimes(1);
+	});
+
+	it("does not call onClose when clicking inside the modal content", async () => {
+		const user = userEvent.setup();
+		const onClose = vi.fn();
+		render(<CreateDeckModal {...defaultProps} onClose={onClose} />);
+
+		// Click on an element inside the modal
+		await user.click(screen.getByLabelText("Name"));
+
+		expect(onClose).not.toHaveBeenCalled();
+	});
+
+	it("creates deck with name only", async () => {
+		const user = userEvent.setup();
+		const onClose = vi.fn();
+		const onDeckCreated = vi.fn();
+
+		vi.mocked(apiClient.rpc.api.decks.$post).mockResolvedValue(
+			mockResponse({
+				ok: true,
+				json: async () => ({
+					deck: {
+						id: "deck-1",
+						name: "Test Deck",
+						description: null,
+						newCardsPerDay: 20,
+					},
+				}),
+			}),
+		);
+
+		render(
+			<CreateDeckModal
+				isOpen={true}
+				onClose={onClose}
+				onDeckCreated={onDeckCreated}
+			/>,
+		);
+
+		await user.type(screen.getByLabelText("Name"), "Test Deck");
+		await user.click(screen.getByRole("button", { name: "Create" }));
+
+		await waitFor(() => {
+			expect(apiClient.rpc.api.decks.$post).toHaveBeenCalledWith(
+				{ json: { name: "Test Deck", description: null } },
+				{ headers: { Authorization: "Bearer access-token" } },
+			);
+		});
+
+		expect(onDeckCreated).toHaveBeenCalledTimes(1);
+		expect(onClose).toHaveBeenCalledTimes(1);
+	});
+
+	it("creates deck with name and description", async () => {
+		const user = userEvent.setup();
+		const onClose = vi.fn();
+		const onDeckCreated = vi.fn();
+
+		vi.mocked(apiClient.rpc.api.decks.$post).mockResolvedValue(
+			mockResponse({
+				ok: true,
+				json: async () => ({
+					deck: {
+						id: "deck-1",
+						name: "Test Deck",
+						description: "A test description",
+						newCardsPerDay: 20,
+					},
+				}),
+			}),
+		);
+
+		render(
+			<CreateDeckModal
+				isOpen={true}
+				onClose={onClose}
+				onDeckCreated={onDeckCreated}
+			/>,
+		);
+
+		await user.type(screen.getByLabelText("Name"), "Test Deck");
+		await user.type(
+			screen.getByLabelText("Description (optional)"),
+			"A test description",
+		);
+		await user.click(screen.getByRole("button", { name: "Create" }));
+
+		await waitFor(() => {
+			expect(apiClient.rpc.api.decks.$post).toHaveBeenCalledWith(
+				{ json: { name: "Test Deck", description: "A test description" } },
+				{ headers: { Authorization: "Bearer access-token" } },
+			);
+		});
+
+		expect(onDeckCreated).toHaveBeenCalledTimes(1);
+		expect(onClose).toHaveBeenCalledTimes(1);
+	});
+
+	it("trims whitespace from name and description", async () => {
+		const user = userEvent.setup();
+
+		vi.mocked(apiClient.rpc.api.decks.$post).mockResolvedValue(
+			mockResponse({
+				ok: true,
+				json: async () => ({ deck: { id: "deck-1" } }),
+			}),
+		);
+
+		render(<CreateDeckModal {...defaultProps} />);
+
+		await user.type(screen.getByLabelText("Name"), "  Test Deck  ");
+		await user.type(
+			screen.getByLabelText("Description (optional)"),
+			"  Description  ",
+		);
+		await user.click(screen.getByRole("button", { name: "Create" }));
+
+		await waitFor(() => {
+			expect(apiClient.rpc.api.decks.$post).toHaveBeenCalledWith(
+				{ json: { name: "Test Deck", description: "Description" } },
+				{ headers: { Authorization: "Bearer access-token" } },
+			);
+		});
+	});
+
+	it("shows loading state during submission", async () => {
+		const user = userEvent.setup();
+
+		vi.mocked(apiClient.rpc.api.decks.$post).mockImplementation(
+			() => new Promise(() => {}), // Never resolves
+		);
+
+		render(<CreateDeckModal {...defaultProps} />);
+
+		await user.type(screen.getByLabelText("Name"), "Test Deck");
+		await user.click(screen.getByRole("button", { name: "Create" }));
+
+		expect(screen.getByRole("button", { name: "Creating..." })).toBeDefined();
+		expect(screen.getByRole("button", { name: "Creating..." })).toHaveProperty(
+			"disabled",
+			true,
+		);
+		expect(screen.getByRole("button", { name: "Cancel" })).toHaveProperty(
+			"disabled",
+			true,
+		);
+		expect(screen.getByLabelText("Name")).toHaveProperty("disabled", true);
+		expect(screen.getByLabelText("Description (optional)")).toHaveProperty(
+			"disabled",
+			true,
+		);
+	});
+
+	it("displays API error message", async () => {
+		const user = userEvent.setup();
+
+		vi.mocked(apiClient.rpc.api.decks.$post).mockResolvedValue(
+			mockResponse({
+				ok: false,
+				status: 400,
+				json: async () => ({ error: "Deck name already exists" }),
+			}),
+		);
+
+		render(<CreateDeckModal {...defaultProps} />);
+
+		await user.type(screen.getByLabelText("Name"), "Test Deck");
+		await user.click(screen.getByRole("button", { name: "Create" }));
+
+		await waitFor(() => {
+			expect(screen.getByRole("alert").textContent).toContain(
+				"Deck name already exists",
+			);
+		});
+	});
+
+	it("displays generic error on unexpected failure", async () => {
+		const user = userEvent.setup();
+
+		vi.mocked(apiClient.rpc.api.decks.$post).mockRejectedValue(
+			new Error("Network error"),
+		);
+
+		render(<CreateDeckModal {...defaultProps} />);
+
+		await user.type(screen.getByLabelText("Name"), "Test Deck");
+		await user.click(screen.getByRole("button", { name: "Create" }));
+
+		await waitFor(() => {
+			expect(screen.getByRole("alert").textContent).toContain(
+				"Failed to create deck. Please try again.",
+			);
+		});
+	});
+
+	it("resets form when closed and reopened", async () => {
+		const user = userEvent.setup();
+		const onClose = vi.fn();
+
+		const { rerender } = render(
+			<CreateDeckModal
+				isOpen={true}
+				onClose={onClose}
+				onDeckCreated={vi.fn()}
+			/>,
+		);
+
+		// Type something in the form
+		await user.type(screen.getByLabelText("Name"), "Test Deck");
+		await user.type(
+			screen.getByLabelText("Description (optional)"),
+			"Test Description",
+		);
+
+		// Click cancel to close
+		await user.click(screen.getByRole("button", { name: "Cancel" }));
+
+		// Reopen the modal
+		rerender(
+			<CreateDeckModal
+				isOpen={true}
+				onClose={onClose}
+				onDeckCreated={vi.fn()}
+			/>,
+		);
+
+		// Form should be reset
+		expect(screen.getByLabelText("Name")).toHaveProperty("value", "");
+		expect(screen.getByLabelText("Description (optional)")).toHaveProperty(
+			"value",
+			"",
+		);
+	});
+
+	it("resets form after successful creation", async () => {
+		const user = userEvent.setup();
+		const onClose = vi.fn();
+
+		vi.mocked(apiClient.rpc.api.decks.$post).mockResolvedValue(
+			mockResponse({
+				ok: true,
+				json: async () => ({ deck: { id: "deck-1" } }),
+			}),
+		);
+
+		const { rerender } = render(
+			<CreateDeckModal
+				isOpen={true}
+				onClose={onClose}
+				onDeckCreated={vi.fn()}
+			/>,
+		);
+
+		// Create a deck
+		await user.type(screen.getByLabelText("Name"), "Test Deck");
+		await user.click(screen.getByRole("button", { name: "Create" }));
+
+		await waitFor(() => {
+			expect(onClose).toHaveBeenCalled();
+		});
+
+		// Reopen the modal
+		rerender(
+			<CreateDeckModal
+				isOpen={true}
+				onClose={onClose}
+				onDeckCreated={vi.fn()}
+			/>,
+		);
+
+		// Form should be reset
+		expect(screen.getByLabelText("Name")).toHaveProperty("value", "");
+		expect(screen.getByLabelText("Description (optional)")).toHaveProperty(
+			"value",
+			"",
+		);
+	});
+});