Implement scroll position management for navigation (#73)

* feat: implement scroll position management for main page navigation

* fix: import saveMainPageScrollPosition in ServerCard and ServerCardInline components

* feat: save scroll position when navigating to server from DashCommand

* fix: prevent restoring stale scroll positions without main page origin

src/test/components/dash-command.test.tsx

@@ -83,8 +83,14 @@ describe("DashCommand", () => {
 		expect(screen.getByText("edge-7")).toBeInTheDocument();
 		expect(screen.getByText("ToggleDarkMode")).toBeInTheDocument();
 
+		Object.defineProperty(window, "scrollY", {
+			configurable: true,
+			value: 256,
+		});
 		await user.click(screen.getByText("edge-7"));
 		expect(dashMocks.navigate).toHaveBeenCalledWith("/server/7");
+		expect(sessionStorage.getItem("fromMainPage")).toBe("true");
+		expect(sessionStorage.getItem("scrollPosition")).toBe("256");
 		expect(dashMocks.closeCommand).toHaveBeenCalled();
 
 		await user.click(screen.getByText("ToggleDarkMode"));

src/test/components/header.test.tsx

@@ -179,6 +179,19 @@ describe("Header", () => {
 		).toBeInTheDocument();
 	});
 
+	it("ignores invalid custom links instead of crashing", async () => {
+		Object.assign(window, {
+			CustomLinks: "{bad-json",
+		});
+
+		renderHeader();
+
+		expect(await screen.findByText("Nezha")).toBeInTheDocument();
+		expect(
+			screen.queryByRole("link", { name: "Docs" }),
+		).not.toBeInTheDocument();
+	});
+
 	it("stores and removes the active custom background", async () => {
 		const user = userEvent.setup();
 		headerMocks.backgroundImage = "/desktop.png";

src/test/components/navigation-and-footer.test.tsx

@@ -104,6 +104,7 @@ describe("Tab and group switches", () => {
 	it("scrolls overflowing group tabs and applies custom background styling", async () => {
 		const user = userEvent.setup();
 		const setCurrentTab = vi.fn();
+		const scrollIntoView = vi.spyOn(HTMLElement.prototype, "scrollIntoView");
 		vi.spyOn(HTMLElement.prototype, "scrollWidth", "get").mockReturnValue(320);
 		vi.spyOn(HTMLElement.prototype, "clientWidth", "get").mockReturnValue(120);
 		window.CustomBackgroundImage = "/background.jpg";
@@ -125,6 +126,7 @@ describe("Tab and group switches", () => {
 
 		expect(scrollContainer.scrollLeft).toBe(42);
 		expect(setCurrentTab).toHaveBeenCalledWith("Asia");
+		expect(scrollIntoView).not.toHaveBeenCalled();
 		expect(
 			container.querySelector(".relative.flex.items-center")?.className,
 		).toContain("bg-stone-100/70");

src/test/components/server-cards.test.tsx

@@ -72,9 +72,14 @@ describe("ServerCard", () => {
 			screen.getAllByText(/billingInfo.remaining: 16/).length,
 		).toBeGreaterThan(0);
 
+		Object.defineProperty(window, "scrollY", {
+			configurable: true,
+			value: 432,
+		});
 		fireEvent.click(screen.getByText("edge-online"));
 
 		expect(sessionStorage.getItem("fromMainPage")).toBe("true");
+		expect(sessionStorage.getItem("scrollPosition")).toBe("432");
 		expect(screen.getByText("/server/7")).toBeInTheDocument();
 	});
 

src/test/components/server-detail-components.test.tsx

@@ -99,6 +99,7 @@ describe("ServerDetailOverview", () => {
 
 	it("renders server identity, hardware, traffic, and temperature details", async () => {
 		const user = userEvent.setup();
+		sessionStorage.setItem("fromMainPage", "true");
 		seedWebSocketData({
 			server: createServer({
 				id: 7,
@@ -113,8 +114,8 @@ describe("ServerDetailOverview", () => {
 			}),
 		});
 
-		render(
-			<MemoryRouter initialEntries={["/server/7"]}>
+		const { unmount } = render(
+			<MemoryRouter initialEntries={["/", "/server/7"]} initialIndex={1}>
 				<ServerDetailOverview server_id="7" />
 				<LocationProbe />
 			</MemoryRouter>,
@@ -139,5 +140,8 @@ describe("ServerDetailOverview", () => {
 
 		await user.click(screen.getByText("edge-detail"));
 		expect(screen.getByText("/")).toBeInTheDocument();
+
+		unmount();
+		expect(sessionStorage.getItem("fromMainPage")).toBeNull();
 	});
 });

src/test/components/service-tracker.test.tsx

@@ -93,6 +93,31 @@ describe("ServiceTracker", () => {
 		expect(screen.getByText("Monthly")).toBeInTheDocument();
 		expect(screen.queryByText("hidden-server")).not.toBeInTheDocument();
 	});
+
+	it("falls back to zero uptime when a service has no checks", async () => {
+		apiMocks.fetchService.mockResolvedValue({
+			success: true,
+			data: {
+				services: {
+					http: {
+						service_name: "HTTP Ping",
+						current_up: 0,
+						current_down: 0,
+						total_up: 0,
+						total_down: 0,
+						delay: [],
+						up: [0, 0],
+						down: [0, 0],
+					},
+				},
+			},
+		});
+
+		renderWithQuery(<ServiceTracker serverList={[createServer()]} />);
+
+		expect(await screen.findByText("HTTP Ping")).toBeInTheDocument();
+		expect(screen.getByText("0.0% serviceTracker.uptime")).toBeInTheDocument();
+	});
 });
 
 describe("CycleTransferStatsCard", () => {

src/test/lib/nezha-api.test.ts

@@ -81,6 +81,9 @@ describe("nezha api fetchers", () => {
 	});
 
 	it("refreshes the token when a logged-in browser session has cookies", async () => {
+		const consoleLog = vi
+			.spyOn(console, "log")
+			.mockImplementation(() => undefined);
 		Object.defineProperty(document, "cookie", {
 			configurable: true,
 			value: "nezha_token=token; nz-csrf=test-csrf-token",
@@ -108,5 +111,6 @@ describe("nezha api fetchers", () => {
 				"X-CSRF-Token": "test-csrf-token",
 			},
 		});
+		expect(consoleLog).not.toHaveBeenCalled();
 	});
 });

src/test/pages/Server.test.tsx

@@ -275,6 +275,73 @@ describe("Servers page", () => {
 		expect(screen.getAllByTestId("server-card")[0]).toHaveTextContent("alpha");
 	});
 
+	it("sorts by system even when a platform value is missing", async () => {
+		const missingPlatform = createServer({
+			id: 1,
+			name: "alpha",
+			host: { platform: undefined },
+		});
+		const linux = createServer({
+			id: 2,
+			name: "beta",
+			host: { platform: "linux" },
+		});
+		const user = userEvent.setup();
+
+		renderServerPage({
+			connected: true,
+			lastData: websocketPayload([missingPlatform, linux]),
+		});
+
+		await user.selectOptions(screen.getByLabelText("Sort metric"), "system");
+
+		const cards = screen.getAllByTestId("server-card");
+		expect(cards).toHaveLength(2);
+		expect(cards[0]).toHaveTextContent("beta");
+		expect(cards[1]).toHaveTextContent("alpha");
+	});
+
+	it("restores the saved main page scroll position after data is ready", async () => {
+		const scrollTo = vi.fn();
+		vi.stubGlobal("scrollTo", scrollTo);
+		vi.spyOn(window, "requestAnimationFrame").mockImplementation((callback) => {
+			callback(0);
+			return 0;
+		});
+		sessionStorage.setItem("fromMainPage", "true");
+		sessionStorage.setItem("scrollPosition", "345");
+
+		renderServerPage({
+			connected: true,
+			lastData: websocketPayload([createServer({ id: 1, name: "alpha" })]),
+		});
+
+		await waitFor(() => {
+			expect(scrollTo).toHaveBeenCalledWith({
+				top: 345,
+				left: 0,
+				behavior: "auto",
+			});
+		});
+	});
+
+	it("does not restore stale scroll positions without a main page origin", () => {
+		const scrollTo = vi.fn();
+		vi.stubGlobal("scrollTo", scrollTo);
+		vi.spyOn(window, "requestAnimationFrame").mockImplementation((callback) => {
+			callback(0);
+			return 0;
+		});
+		sessionStorage.setItem("scrollPosition", "345");
+
+		renderServerPage({
+			connected: true,
+			lastData: websocketPayload([createServer({ id: 1, name: "alpha" })]),
+		});
+
+		expect(scrollTo).not.toHaveBeenCalled();
+	});
+
 	it("toggles map and service tracker controls when service data exists", async () => {
 		apiMocks.fetchService.mockResolvedValue({
 			success: true,