Add test for ProductUpdateController form state preservation

libs/ui/src/presentation/controllers/ProductUpdateController.test.tsx

@@ -0,0 +1,55 @@
+import { renderHook, act } from '@testing-library/react';
+import { useProductUpdateController } from './ProductUpdateController';
+import {
+  MockCategoryRepository,
+  MockProductRepository,
+  MockVariantRepository,
+} from '../../data/mock';
+import { ProductUpdateUsecase } from '../../domain';
+import { flushPromises } from '../../utils/testUtils';
+
+jest.mock('@tamagui/toast', () => ({
+  useToastController: () => ({ show: jest.fn() }),
+}));
+
+describe('useProductUpdateController', () => {
+  it('keeps an in-progress name edit when a background refetch completes mid-edit', async () => {
+    const productRepo = new MockProductRepository();
+    const categoryRepo = new MockCategoryRepository();
+    const variantRepo = new MockVariantRepository();
+    const preloadedProduct = productRepo.products.find((p) => p.id === 1) ?? null;
+
+    const usecase = new ProductUpdateUsecase(productRepo, categoryRepo, variantRepo, {
+      productId: 1,
+      product: preloadedProduct,
+      categories: categoryRepo.categories,
+      variants: [],
+    });
+
+    const { result } = renderHook(() => useProductUpdateController(usecase));
+
+    expect(result.current.state.type).toBe('loaded');
+    expect(result.current.form.getValues('name')).toBe('Product 1');
+
+    // user starts editing the name field
+    act(() => {
+      result.current.form.setValue('name', 'My Typed Name');
+    });
+    expect(result.current.form.getValues('name')).toBe('My Typed Name');
+
+    // something else (e.g. deleting a variant, see ProductUpdateHandler's
+    // `deletingSuccess` effect) triggers a background refetch mid-edit
+    act(() => {
+      result.current.dispatch({ type: 'FETCH' });
+    });
+    expect(result.current.state.type).toBe('loading');
+
+    await act(async () => {
+      await flushPromises();
+    });
+    expect(result.current.state.type).toBe('loaded');
+
+    // the refetch must not clobber values the user already typed
+    expect(result.current.form.getValues('name')).toBe('My Typed Name');
+  });
+});