test(frontend): add comprehensive tests for components, hooks, and state

Add 84 new tests covering Jotai atoms (play/watch state transitions,
game timing, score management), utility functions (calcCodeSize,
checkGameResultKind), UI components (SubmitStatusLabel, LeftTime,
SubmitButton, InputText, BorderedContainerWithCaption,
FoldableBorderedContainerWithCaption, UserIcon, PlayerNameAndIcon),
and the usePageTitle hook.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

1 files changed, 56 insertions, 0 deletions

diff --git a/frontend/app/components/FoldableBorderedContainerWithCaption.test.tsx b/frontend/app/components/FoldableBorderedContainerWithCaption.test.tsx
new file mode 100644
index 0000000..a4434ff
--- /dev/null
+++ b/frontend/app/components/FoldableBorderedContainerWithCaption.test.tsx
@@ -0,0 +1,56 @@
+/**
+ * @vitest-environment jsdom
+ */
+import { cleanup, fireEvent, render, screen } from "@testing-library/react";
+import { afterEach, describe, expect, test } from "vitest";
+import FoldableBorderedContainerWithCaption from "./FoldableBorderedContainerWithCaption";
+
+afterEach(() => {
+	cleanup();
+});
+
+describe("FoldableBorderedContainerWithCaption", () => {
+	test("renders caption", () => {
+		render(
+			<FoldableBorderedContainerWithCaption caption="Foldable Title">
+				Content
+			</FoldableBorderedContainerWithCaption>,
+		);
+		expect(screen.getByText("Foldable Title")).toBeDefined();
+	});
+
+	test("shows children by default (open state)", () => {
+		render(
+			<FoldableBorderedContainerWithCaption caption="Title">
+				<div data-testid="child">Visible</div>
+			</FoldableBorderedContainerWithCaption>,
+		);
+		const child = screen.getByTestId("child");
+		expect(child.parentElement?.className).not.toContain("hidden");
+	});
+
+	test("hides children when toggle button is clicked", () => {
+		render(
+			<FoldableBorderedContainerWithCaption caption="Title">
+				<div data-testid="child">Content</div>
+			</FoldableBorderedContainerWithCaption>,
+		);
+		const toggleButton = screen.getByRole("button");
+		fireEvent.click(toggleButton);
+		const child = screen.getByTestId("child");
+		expect(child.parentElement?.className).toContain("hidden");
+	});
+
+	test("shows children again when toggle button is clicked twice", () => {
+		render(
+			<FoldableBorderedContainerWithCaption caption="Title">
+				<div data-testid="child">Content</div>
+			</FoldableBorderedContainerWithCaption>,
+		);
+		const toggleButton = screen.getByRole("button");
+		fireEvent.click(toggleButton);
+		fireEvent.click(toggleButton);
+		const child = screen.getByTestId("child");
+		expect(child.parentElement?.className).not.toContain("hidden");
+	});
+});