test: remove timing races from screen-sync and route transition tests (#138) (#166)

src/features/tbank-connection/model/screen-sync.test.tsx

@@ -10,6 +10,9 @@ import { server } from "@/test/server";
 
 import { useScreenSync } from "../index";
 
+const TRANSPORT_ATTEMPTS = 3;
+const TRANSPORT_RECOVERY_MS = 3000;
+
 function auth() {
 	configureAuthClient({
 		accessToken: () => "synthetic",
@@ -28,11 +31,13 @@ describe("read-only screen synchronization", () => {
 				gets += 1;
 				syncModes.push(new URL(request.url).searchParams.get("sync"));
 
-				return gets === 1
+				// The transport retries a transient read twice (1 s, 2 s) on its own.
+				return gets <= TRANSPORT_ATTEMPTS
 					? HttpResponse.json({ code: "TBANK_UNAVAILABLE" }, { status: 503 })
 					: HttpResponse.json(resource([]));
 			}),
 		);
+		vi.useFakeTimers();
 
 		const { result } = renderHook(
 			() => {
@@ -46,12 +51,26 @@ describe("read-only screen synchronization", () => {
 			{ wrapper: createQueryWrapper().wrapper },
 		);
 
-		await waitFor(() => expect(gets).toBe(1));
-		await act(async () => result.current.sync.retry());
-		await waitFor(() => expect(result.current.accounts.data).toEqual([]));
+		try {
+			// Exhaust the transport back-off so the query settles in error.
+			await vi.waitFor(async () => {
+				await act(() => vi.advanceTimersByTimeAsync(TRANSPORT_RECOVERY_MS));
+				expect(result.current.sync.transportError).toBe(true);
+			});
+			expect(gets).toBe(TRANSPORT_ATTEMPTS);
 
-		expect(gets).toBe(2);
-		expect(syncModes).toEqual([null, null]);
+			await act(async () => result.current.sync.retry());
+			await vi.waitFor(async () => {
+				await act(() => vi.advanceTimersByTimeAsync(0));
+				expect(result.current.accounts.data).toEqual([]);
+			});
+		}
+		finally {
+			vi.useRealTimers();
+		}
+
+		expect(gets).toBe(TRANSPORT_ATTEMPTS + 1);
+		expect(syncModes).toEqual(Array.from({ length: gets }, () => null));
 	});
 
 	it("refreshes the currently open resources together", async () => {