feat: establish frontend foundation

src/app/routes/AppRoutes.test.tsx

@@ -0,0 +1,81 @@
+import { MantineProvider } from "@mantine/core";
+import { cleanup, render, screen } from "@testing-library/react";
+import { MemoryRouter } from "react-router";
+import { afterEach, describe, expect, it } from "vitest";
+import {
+	AccountsPageEmpty,
+	AccountsPageError,
+	AccountsPageLoading,
+} from "../../pages/accounts";
+import { theme } from "../theme";
+import { AppRoutes } from "./AppRoutes";
+
+describe("AppRoutes", () => {
+	afterEach(cleanup);
+
+	it.each([
+		["/", "Счета"],
+		["/login", "Вход"],
+		["/register", "Регистрация"],
+		["/accounts", "Счета"],
+		["/accounts/demo", "Счет"],
+		["/settings", "Настройки"],
+		["/unknown", "Страница не найдена"],
+	])("renders %s with its page title", (path, title) => {
+		render(
+			<MemoryRouter initialEntries={[path]}>
+				<MantineProvider theme={theme}>
+					<AppRoutes />
+				</MantineProvider>
+			</MemoryRouter>,
+		);
+
+		expect(
+			screen.getByRole("heading", { level: 1, name: title }),
+		).toBeInTheDocument();
+	});
+
+	it("renders only the empty state for accounts by default", () => {
+		render(
+			<MemoryRouter initialEntries={["/accounts"]}>
+				<MantineProvider theme={theme}>
+					<AppRoutes />
+				</MantineProvider>
+			</MemoryRouter>,
+		);
+
+		expect(
+			screen.getByRole("heading", { level: 2, name: "Пока ничего нет" }),
+		).toBeInTheDocument();
+		expect(screen.queryByText("Загрузка")).not.toBeInTheDocument();
+		expect(screen.queryByText("Что-то пошло не так")).not.toBeInTheDocument();
+	});
+
+	it.each([
+		["loading", AccountsPageLoading, "status"],
+		["error", AccountsPageError, "alert"],
+		["empty", AccountsPageEmpty, undefined],
+	] as const)("renders only the Accounts %s state", (_name, State, role) => {
+		render(
+			<MantineProvider theme={theme}>
+				<State />
+			</MantineProvider>,
+		);
+
+		if (role) {
+			expect(screen.getByRole(role)).toBeInTheDocument();
+		} else {
+			expect(
+				screen.getByRole("heading", { level: 2, name: "Пока ничего нет" }),
+			).toBeInTheDocument();
+		}
+
+		expect(screen.queryAllByRole("status")).toHaveLength(
+			role === "status" ? 1 : 0,
+		);
+		expect(screen.queryAllByRole("alert")).toHaveLength(
+			role === "alert" ? 1 : 0,
+		);
+		expect(screen.queryAllByText("Пока ничего нет")).toHaveLength(role ? 0 : 1);
+	});
+});