feat(investments): warn and offer retry after exhausted read retries (WealthLedger/frontend#55) (#136)

src/shared/api/read-failure.test.ts

@@ -0,0 +1,80 @@
+import { describe, expect, it, vi } from "vitest";
+
+import { isReadFailureExhausted, readRetry } from "./read-failure";
+
+const transient = { code: "TBANK_UNAVAILABLE", status: 503 };
+const settled = { isError: true, isFetching: false };
+
+describe("isReadFailureExhausted", () => {
+	it("is true for a settled transient failure, even without a code", () => {
+		expect(isReadFailureExhausted({ ...settled, error: transient })).toBe(true);
+		expect(
+			isReadFailureExhausted({
+				...settled,
+				error: new TypeError("Network request failed"),
+			}),
+		).toBe(true);
+	});
+
+	it("stays true while a manual retry runs and false without a failure", () => {
+		expect(
+			isReadFailureExhausted({
+				error: transient,
+				isError: true,
+				isFetching: true,
+			}),
+		).toBe(true);
+		expect(
+			isReadFailureExhausted({
+				error: null,
+				isError: false,
+				isFetching: false,
+			}),
+		).toBe(false);
+	});
+
+	it.each([
+		"INVALID_TBANK_TOKEN",
+		"NOT_FOUND",
+		"TBANK_NOT_CONNECTED",
+		"UNAUTHORIZED",
+	])("is false for %s, which has its own action", (code) => {
+		expect(isReadFailureExhausted({ ...settled, error: { code } })).toBe(false);
+	});
+});
+
+describe("readRetry", () => {
+	it("refetches only the failed reads and reports a running retry", () => {
+		const failedRefetch = vi.fn(() => Promise.resolve());
+		const healthyRefetch = vi.fn(() => Promise.resolve());
+
+		const retry = readRetry([
+			{ ...settled, error: transient, refetch: failedRefetch },
+			{
+				error: null,
+				isError: false,
+				isFetching: true,
+				refetch: healthyRefetch,
+			},
+			{ ...settled, error: { code: "NOT_FOUND" }, refetch: healthyRefetch },
+		]);
+
+		expect(retry).toMatchObject({ exhausted: true, retrying: false });
+		retry.onRetry();
+		expect(failedRefetch).toHaveBeenCalledOnce();
+		expect(healthyRefetch).not.toHaveBeenCalled();
+	});
+
+	it("is not exhausted while every read is healthy", () => {
+		expect(
+			readRetry([
+				{
+					error: null,
+					isError: false,
+					isFetching: false,
+					refetch: vi.fn(() => Promise.resolve()),
+				},
+			]).exhausted,
+		).toBe(false);
+	});
+});