chore: finish frontend ESLint migration #18

Enable every plugin recommended preset and replace Biome with ESLint formatting.

Preserve API contracts and JSX whitespace; verify source, tests, builds and tooling.

src/test/handlers.ts

@@ -1,9 +1,10 @@
-import { HttpResponse, http } from "msw";
+import { http, HttpResponse } from "msw";
+
 import { resource } from "@/test/resource";
 
 const authentication = {
 	accessToken: "test-token",
-	user: { id: "user-1", email: "user@example.com" },
+	user: { email: "user@example.com", id: "user-1" },
 };
 
 const handlers = [
@@ -18,7 +19,9 @@ const handlers = [
 	),
 	http.get("*/api/v1/auth/me", () => HttpResponse.json(authentication.user)),
 	http.get("*/api/v1/tbank-connection", () =>
-		HttpResponse.json({ connected: false, connectedAt: null }),
+		HttpResponse.json((/* eslint-disable unicorn/no-null -- Fixture preserves the production contract’s explicit null values. */
+			{ connected: false, connectedAt: null }
+			/* eslint-enable unicorn/no-null */)),
 	),
 	http.put("*/api/v1/tbank-connection", () =>
 		HttpResponse.json({ connected: true, connectedAt: "2026-08-14T00:00:00Z" }),
@@ -33,24 +36,26 @@ const handlers = [
 	http.get("*/api/v1/brokerage-accounts/:accountId/portfolio", () =>
 		HttpResponse.json(
 			resource({
-				lastSuccessfulAt: "2026-08-14T00:00:00Z",
+				cashBalances: [],
 				isStale: false,
-				totalsByCurrency: [],
+				lastSuccessfulAt: "2026-08-14T00:00:00Z",
 				positions: [],
 				structure: { currencies: [], unvaluedCategories: [] },
-				cashBalances: [],
+				totalsByCurrency: [],
 			}),
 		),
 	),
 	http.get("*/api/v1/brokerage-accounts/:accountId/operations", () =>
 		HttpResponse.json(
-			resource({
-				accountId: "account-1",
-				items: [],
-				nextCursor: null,
-				hasNext: false,
-				observedAt: "2026-08-14T00:00:00Z",
-			}),
+			resource((/* eslint-disable unicorn/no-null -- Fixture preserves the production contract’s explicit null values. */
+				{
+					accountId: "account-1",
+					hasNext: false,
+					items: [],
+					nextCursor: null,
+					observedAt: "2026-08-14T00:00:00Z",
+				}
+				/* eslint-enable unicorn/no-null */)),
 		),
 	),
 	http.get("*/api/v1/brokerage-accounts/:accountId/events", () =>
@@ -66,9 +71,9 @@ const handlers = [
 		HttpResponse.json(
 			resource({
 				accountId: "account-1",
+				calculatedAt: "2026-08-14T00:00:00Z",
 				period: { from: "2026-01-01", to: "2026-08-14" },
 				totalsByCurrency: [],
-				calculatedAt: "2026-08-14T00:00:00Z",
 			}),
 		),
 	),

src/test/query.tsx

@@ -1,17 +1,9 @@
-import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 import type { FC, PropsWithChildren } from "react";
 
-function createTestQueryClient(): QueryClient {
-	return new QueryClient({
-		defaultOptions: {
-			queries: { retry: false },
-			mutations: { retry: false },
-		},
-	});
-}
+import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 
 function createQueryWrapper(queryClient = createTestQueryClient()) {
-	const QueryWrapper: FC<PropsWithChildren> = (props) => (
+	const QueryWrapper: FC<PropsWithChildren> = props => (
 		<QueryClientProvider client={queryClient}>
 			{props.children}
 		</QueryClientProvider>
@@ -20,4 +12,13 @@ function createQueryWrapper(queryClient = createTestQueryClient()) {
 	return { queryClient, wrapper: QueryWrapper };
 }
 
+function createTestQueryClient(): QueryClient {
+	return new QueryClient({
+		defaultOptions: {
+			mutations: { retry: false },
+			queries: { retry: false },
+		},
+	});
+}
+
 export { createQueryWrapper, createTestQueryClient };

src/test/resource.ts

@@ -1,21 +1,23 @@
 import type { paths } from "@/shared/api";
 
-type Meta =
-	paths["/api/v1/brokerage-accounts"]["get"]["responses"][200]["content"]["application/json"]["meta"];
+type Meta
+	= paths["/api/v1/brokerage-accounts"]["get"]["responses"][200]["content"]["application/json"]["meta"];
 function resource<T>(data: T, meta: Partial<Meta> = {}) {
-	return {
-		data,
-		meta: {
-			resourceKey: "fixture",
-			dataRevision: "1",
-			stateVersion: "1",
-			availability: data === null ? "missing" : "complete",
-			freshness: "fresh",
-			lastSuccessfulAt: "2026-08-14T00:00:00Z",
-			sync: { id: null, state: "idle", errorCode: null },
-			...meta,
-		} satisfies Meta,
-	};
+	return (/* eslint-disable unicorn/no-null -- Fixture preserves the production contract’s explicit null values. */
+		{
+			data,
+			meta: {
+				availability: data === null ? "missing" : "complete",
+				dataRevision: "1",
+				freshness: "fresh",
+				lastSuccessfulAt: "2026-08-14T00:00:00Z",
+				resourceKey: "fixture",
+				stateVersion: "1",
+				sync: { errorCode: null, id: null, state: "idle" },
+				...meta,
+			} satisfies Meta,
+		}
+	/* eslint-enable unicorn/no-null */);
 }
 
 export { resource };

src/test/server.ts

@@ -1,4 +1,5 @@
 import { setupServer } from "msw/node";
+
 import { handlers } from "./handlers";
 
 const server = setupServer(...handlers);

src/test/setup.ts

@@ -1,28 +1,30 @@
 import "@testing-library/jest-dom/vitest";
 import { cleanup, configure } from "@testing-library/react";
-import { afterAll, afterEach, beforeAll } from "vitest";
+import { afterAll, afterEach, beforeAll, vi } from "vitest";
+
 import { configureAuthClient } from "@/shared/api";
+
 import "../shared/i18n";
 import { server } from "./server";
 
 // Allow async UI updates on the slower CI runner; local waits stay unchanged.
-if (process.env.CI) configure({ asyncUtilTimeout: 5_000 });
+if (process.env.CI) configure({ asyncUtilTimeout: 5000 });
 
 beforeAll(() => server.listen({ onUnhandledRequest: "error" }));
 afterEach(() => {
 	cleanup();
-	configureAuthClient(null);
+	configureAuthClient();
 	server.resetHandlers();
 });
 afterAll(() => server.close());
 
 class ResizeObserver {
+	disconnect() {}
 	observe() {}
 	unobserve() {}
-	disconnect() {}
 }
 
-window.ResizeObserver = ResizeObserver;
+vi.stubGlobal("ResizeObserver", ResizeObserver);
 
 // JSDOM has no layout/scrolling; Mantine Combobox scrolls the active option.
 Object.defineProperty(HTMLElement.prototype, "scrollIntoView", {
@@ -30,16 +32,16 @@ Object.defineProperty(HTMLElement.prototype, "scrollIntoView", {
 	value: () => {},
 });
 
-Object.defineProperty(window, "matchMedia", {
-	writable: true,
+Object.defineProperty(globalThis, "matchMedia", {
 	value: (query: string) => ({
+		addEventListener: () => {},
+		addListener: () => {},
+		dispatchEvent: () => false,
 		matches: false,
 		media: query,
-		onchange: null,
-		addEventListener: () => {},
+		onchange: /* eslint-disable-line unicorn/no-null -- Exercise the explicit null returned by the production API/DOM contract. */ null,
 		removeEventListener: () => {},
-		addListener: () => {},
 		removeListener: () => {},
-		dispatchEvent: () => false,
 	}),
+	writable: true,
 });

src/test/storybook.test.tsx

@@ -1,17 +1,18 @@
 import { composeStories } from "@storybook/react-vite";
+// eslint-disable-next-line testing-library/no-manual-cleanup -- Vitest globals are disabled, so RTL cannot register its automatic afterEach cleanup.
 import { cleanup, fireEvent, render, screen } from "@testing-library/react";
 import { fn } from "storybook/test";
 import { afterEach, describe, expect, it, vi } from "vitest";
+
 import preview from "../../.storybook/preview";
 import * as UiLoadingStories from "../../packages/ui/src/LoadingSkeleton/LoadingSkeleton.stories";
 import * as StateStories from "../../packages/ui/src/StateView/StateView.stories";
 import * as AccountStories from "../entities/brokerage-account/ui/BrokerageAccountList/BrokerageAccountList.stories";
 import * as EventStories from "../entities/brokerage-event/ui/BrokerageEventsPreview/BrokerageEventsPreview.stories";
+import * as IncomePeriodStories from "../pages/account-income/ui/AccountIncomePage/components/IncomePeriodForm/IncomePeriodForm.stories";
 import * as LoadingStories from "../pages/account/ui/AccountPage/components/AccountPageLoading/AccountPageLoading.stories";
 import * as RefreshStories from "../pages/account/ui/AccountPage/components/PortfolioRefreshState/PortfolioRefreshState.stories";
 import * as PositionStories from "../pages/account/ui/AccountPage/components/PositionCard/PositionCard.stories";
-import * as IncomePeriodStories from "../pages/account-income/ui/AccountIncomePage/components/IncomePeriodForm/IncomePeriodForm.stories";
-
 import * as OperationStories from "../pages/card/ui/OperationForm/OperationForm.stories";
 
 afterEach(() => vi.restoreAllMocks());
@@ -59,7 +60,7 @@ describe("Storybook isolated product examples", () => {
 		fireEvent.click(screen.getByRole("button"));
 		expect(retry).toHaveBeenCalledOnce();
 		view.rerender(
-			<RefreshError refreshing refreshError={false} retry={retry} />,
+			<RefreshError refreshError={false} refreshing retry={retry} />,
 		);
 		expect(screen.getByText(/125\s*000,50/)).toBeVisible();
 		expect(screen.getByRole("status")).toBeVisible();