frontend/src/shared/api/client.test.ts

import { http, HttpResponse } from "msw";
import { afterEach, describe, expect, it, vi } from "vitest";

import { resource } from "@/test/resource";
import { server } from "@/test/server";

import { apiClient, configureAuthClient } from "./client";

async function advanceReadDeadlineRecovery() {
	await vi.advanceTimersByTimeAsync(15_000);
	await vi.advanceTimersByTimeAsync(1000);
}

async function advanceTransportRecovery() {
	await vi.advanceTimersByTimeAsync(1000);
	await vi.advanceTimersByTimeAsync(2000);
}

describe("apiClient authentication", () => {
	afterEach(() => {
		vi.useRealTimers();
	});

	it("refreshes once and retries an unauthorized protected request", async () => {
		let token = "expired";

		const refresh = vi.fn(() => {
			token = "fresh";

			return Promise.resolve(true);
		});

		const authorization: string[] = [];
		server.use(
			http.get("*/api/v1/brokerage-accounts", ({ request }) => {
				authorization.push(request.headers.get("Authorization") ?? "");

				return authorization.length === 1
					? HttpResponse.json({ code: "UNAUTHORIZED" }, { status: 401 })
					: HttpResponse.json(resource([]));
			}),
		);
		configureAuthClient({ accessToken: () => token, clear: vi.fn(), refresh });

		const { data } = await apiClient.GET("/api/v1/brokerage-accounts");

		expect(data?.data).toEqual([]);
		expect(refresh).toHaveBeenCalledOnce();
		expect(authorization).toEqual(["Bearer expired", "Bearer fresh"]);
	});

	it("clears the session when refresh cannot restore it", async () => {
		const clear = vi.fn();
		server.use(
			http.get("*/api/v1/brokerage-accounts", () =>
				HttpResponse.json({ code: "UNAUTHORIZED" }, { status: 401 }),
			),
		);
		configureAuthClient({
			accessToken: () => "expired",
			clear,
			refresh: () => Promise.resolve(false),
		});

		await apiClient.GET("/api/v1/brokerage-accounts");

		expect(clear).toHaveBeenCalledOnce();
	});

	it("keeps the session when refresh failed because the server was unreachable", async () => {
		const clear = vi.fn();
		server.use(
			http.get("*/api/v1/brokerage-accounts", () =>
				HttpResponse.json({ code: "UNAUTHORIZED" }, { status: 401 }),
			),
		);
		configureAuthClient({
			accessToken: () => "expired",
			clear,
			refresh: () => Promise.resolve(false),
			unavailable: () => true,
		});

		await apiClient.GET("/api/v1/brokerage-accounts");

		expect(clear).not.toHaveBeenCalled();
	});

	it("does not attach Bearer auth to authentication endpoints", async () => {
		let authorization: null | string

			= null;

		server.use(
			http.post("*/api/v1/auth/refresh", ({ request }) => {
				authorization = request.headers.get("Authorization");

				return HttpResponse.json({ code: "UNAUTHORIZED" }, { status: 401 });
			}),
		);
		configureAuthClient({
			accessToken: () => "token",
			clear: vi.fn(),
			refresh: vi.fn(),
		});

		await apiClient.POST("/api/v1/auth/refresh");

		expect(authorization).toBeNull();
	});
	it("discards a retried request response after another session takes over", async () => {
		let generation = 0;
		let calls = 0;

		const { promise: pending, resolve: release }
			= Promise.withResolvers<void>();

		server.use(
			http.get("*/api/v1/brokerage-accounts", async () => {
				if (++calls === 1)
					return HttpResponse.json({ code: "UNAUTHORIZED" }, { status: 401 });
				await pending;

				return HttpResponse.json(resource([{ id: "previous-user-account" }]));
			}),
		);
		configureAuthClient({
			accessToken: () => "synthetic",
			clear: vi.fn(),
			generation: () => generation,
			refresh: () => Promise.resolve(true),
		});

		// eslint-disable-next-line vitest/valid-expect -- Attach rejection handling before releasing the request; the assertion is awaited below.
		const response = expect(
			apiClient.GET("/api/v1/brokerage-accounts"),
		).rejects.toMatchObject({ name: "AbortError" });

		await vi.waitFor(() => expect(calls).toBe(2));
		generation += 1;
		release();
		await response;
	});
});

describe("apiClient transient read recovery", () => {
	afterEach(() => {
		vi.useRealTimers();
	});

	it("recovers a protected GET after transient server failures", async () => {
		vi.useFakeTimers();
		let requests = 0;
		server.use(
			http.get("*/api/v1/brokerage-accounts", () => {
				requests += 1;

				return requests < 3
					? HttpResponse.json({ code: "TBANK_UNAVAILABLE" }, { status: 503 })
					: HttpResponse.json(resource([{ id: "account-1" }]));
			}),
		);
		configureAuthClient({
			accessToken: () => "token",
			clear: vi.fn(),
			refresh: () => Promise.resolve(true),
		});

		const response = apiClient.GET("/api/v1/brokerage-accounts");
		await advanceTransportRecovery();

		await expect(response).resolves.toMatchObject({
			data: { data: [{ id: "account-1" }] },
		});
		expect(requests).toBe(3);
	});

	it("recovers a protected GET after network failure", async () => {
		vi.useFakeTimers();
		let requests = 0;
		server.use(
			http.get("*/api/v1/brokerage-accounts", () => {
				requests += 1;

				return requests === 1
					? HttpResponse.error()
					: HttpResponse.json(resource([{ id: "account-1" }]));
			}),
		);
		configureAuthClient({
			accessToken: () => "token",
			clear: vi.fn(),
			refresh: () => Promise.resolve(true),
		});

		const response = apiClient.GET("/api/v1/brokerage-accounts");
		await advanceTransportRecovery();

		await expect(response).resolves.toMatchObject({
			data: { data: [{ id: "account-1" }] },
		});
		expect(requests).toBe(2);
	});

	it("times out a stalled response body before retrying", async () => {
		vi.useFakeTimers();
		let requests = 0;
		server.use(
			http.get("*/api/v1/brokerage-accounts", () => {
				requests += 1;

				return requests === 1
					? new Response(new ReadableStream())
					: HttpResponse.json(resource([{ id: "account-1" }]));
			}),
		);
		configureAuthClient({
			accessToken: () => "token",
			clear: vi.fn(),
			refresh: () => Promise.resolve(true),
		});

		const response = apiClient.GET("/api/v1/brokerage-accounts");
		await advanceReadDeadlineRecovery();

		await expect(response).resolves.toMatchObject({
			data: { data: [{ id: "account-1" }] },
		});
		expect(requests).toBe(2);
	});

	it("does not retry rate limited reads before the server delay", async () => {
		let requests = 0;
		server.use(
			http.get("*/api/v1/brokerage-accounts", () => {
				requests += 1;

				return HttpResponse.json(
					{ code: "RATE_LIMITED" },
					{ headers: { "Retry-After": "60" }, status: 429 },
				);
			}),
		);
		configureAuthClient({
			accessToken: () => "token",
			clear: vi.fn(),
			refresh: () => Promise.resolve(true),
		});

		await apiClient.GET("/api/v1/brokerage-accounts");

		expect(requests).toBe(1);
	});

	it("does not retry malformed successful responses as transport failures", async () => {
		let requests = 0;
		server.use(
			http.get("*/api/v1/brokerage-accounts", () => {
				requests += 1;

				return new Response("not json", {
					headers: { "Content-Type": "application/json" },
					status: 200,
				});
			}),
		);
		configureAuthClient({
			accessToken: () => "token",
			clear: vi.fn(),
			refresh: () => Promise.resolve(true),
		});

		await expect(
			apiClient.GET("/api/v1/brokerage-accounts"),
		).rejects.toThrow(SyntaxError);

		expect(requests).toBe(1);
	});

	it.each([401, 403, 404, 409])(
		"does not retry permanent HTTP %s responses",
		async (status) => {
			let requests = 0;
			server.use(
				http.get("*/api/v1/brokerage-accounts", () => {
					requests += 1;

					// Any non-transient code; status alone must prevent the retry.
					return HttpResponse.json(
						{ code: "INTERNAL_SERVER_ERROR", status },
						{ status },
					);
				}),
			);
			configureAuthClient({
				accessToken: () => "token",
				clear: vi.fn(),
				refresh: () => Promise.resolve(false),
			});

			await apiClient.GET("/api/v1/brokerage-accounts");

			expect(requests).toBe(1);
		},
	);

	it("does not retry a read refused with INVALID_TBANK_TOKEN", async () => {
		let requests = 0;
		server.use(
			http.get("*/api/v1/brokerage-accounts", () => {
				requests += 1;

				return HttpResponse.json(
					{ code: "INVALID_TBANK_TOKEN", status: 400 },
					{ status: 400 },
				);
			}),
		);
		configureAuthClient({
			accessToken: () => "token",
			clear: vi.fn(),
			refresh: () => Promise.resolve(false),
		});

		const { error, response } = await apiClient.GET(
			"/api/v1/brokerage-accounts",
		);

		expect(response.status).toBe(400);
		expect(error).toMatchObject({ code: "INVALID_TBANK_TOKEN" });
		expect(requests).toBe(1);
	});

	it("does not retry mutations", async () => {
		let requests = 0;
		server.use(
			http.put("*/api/v1/tbank-connection", () => {
				requests += 1;

				return HttpResponse.json(
					{ code: "TBANK_UNAVAILABLE" },
					{ status: 503 },
				);
			}),
		);
		configureAuthClient({
			accessToken: () => "token",
			clear: vi.fn(),
			refresh: () => Promise.resolve(true),
		});

		await apiClient.PUT("/api/v1/tbank-connection", {
			body: { token: "token" },
		});

		expect(requests).toBe(1);
	});
});