test: add unit test

packages/ui-client/src/hooks/useUserDisplayName.spec.ts

@@ -0,0 +1,36 @@
+import { mockAppRoot } from '@rocket.chat/mock-providers';
+import { renderHook } from '@testing-library/react';
+
+import { useUserDisplayName } from './useUserDisplayName';
+
+const fakeUser = {
+	name: 'John Doe',
+	username: 'john.doe',
+};
+
+it('should return username if UI_Use_Real_Name setting is false', () => {
+	const { result } = renderHook(() => useUserDisplayName(fakeUser), {
+		legacyRoot: true,
+		wrapper: mockAppRoot().withSetting('UI_Use_Real_Name', false).build(),
+	});
+
+	expect(result.current).toBe(fakeUser.username);
+});
+
+it('should return name if UI_Use_Real_Name setting is true', () => {
+	const { result } = renderHook(() => useUserDisplayName(fakeUser), {
+		legacyRoot: true,
+		wrapper: mockAppRoot().withSetting('UI_Use_Real_Name', true).build(),
+	});
+
+	expect(result.current).toBe(fakeUser.name);
+});
+
+it('should return username if UI_Use_Real_Name setting is true and user has no name', () => {
+	const { result } = renderHook(() => useUserDisplayName({ ...fakeUser, name: undefined }), {
+		legacyRoot: true,
+		wrapper: mockAppRoot().withSetting('UI_Use_Real_Name', true).build(),
+	});
+
+	expect(result.current).toBe(fakeUser.username);
+});