fix: stabilize auth client registration (WealthLedger/frontend#95)

src/features/auth/model/auth.test.tsx

@@ -3,8 +3,9 @@ import type { FC, PropsWithChildren } from "react";
 import { QueryClientProvider, useQueryClient } from "@tanstack/react-query";
 import { act, renderHook, waitFor } from "@testing-library/react";
 import { http, HttpResponse } from "msw";
-import { describe, expect, it } from "vitest";
+import { describe, expect, it, onTestFinished, vi } from "vitest";
 
+import * as sharedApi from "@/shared/api";
 import { apiClient, apiQueryClient, useAuthenticatedQuery } from "@/shared/api";
 import { createTestQueryClient } from "@/test/query";
 import { resource } from "@/test/resource";
@@ -398,4 +399,23 @@ describe("AuthProvider", () => {
 			expect(result.current.cards.data?.[0]?.id).toBe("b-card"),
 		);
 	});
+
+	it("registers auth handlers once until unmount", async () => {
+		const configure = vi.spyOn(sharedApi, "configureAuthClient");
+		onTestFinished(() => configure.mockRestore());
+
+		const { rerender, result, unmount } = renderHook(useAuth, {
+			wrapper: createAuthWrapper(createTestQueryClient()),
+		});
+
+		await waitFor(() => expect(result.current.ready).toBe(true));
+		const registrations = configure.mock.calls.length;
+
+		rerender();
+		expect(configure).toHaveBeenCalledTimes(registrations);
+
+		unmount();
+		expect(configure).toHaveBeenCalledTimes(registrations + 1);
+		expect(configure).toHaveBeenLastCalledWith();
+	});
 });

src/features/auth/model/auth.vm.ts

@@ -161,7 +161,8 @@ function useAuthProviderVm() {
 			refresh,
 			unavailable: () => unavailableRef.current,
 		});
-	});
+		// `user` tracks access-token changes, which configureAuthClient publishes as session state.
+	}, [clearSession, refresh, user]);
 	useEffect(() => () => configureAuthClient(), []);
 
 	const authContextValue = {