53 lines
1.4 KiB
TypeScript
53 lines
1.4 KiB
TypeScript
// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
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// See LICENSE.txt for license information.
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import {renderHook, act} from '@testing-library/react-native';
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import useDidUpdate from './did_update';
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describe('useDidUpdate', () => {
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test('should not call callback on mount', () => {
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const callback = jest.fn();
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renderHook(() => useDidUpdate(callback));
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expect(callback).not.toHaveBeenCalled();
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});
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test('should call callback when dependencies change', () => {
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const callback = jest.fn();
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const {rerender} = renderHook(({dep}) => useDidUpdate(callback, [dep]), {
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initialProps: {dep: 1},
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});
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expect(callback).not.toHaveBeenCalled();
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act(() => {
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rerender({dep: 2});
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});
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expect(callback).toHaveBeenCalledTimes(1);
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});
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test('should maintain mounted state across re-renders with same deps', () => {
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const callback = jest.fn();
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const {rerender} = renderHook(({dep}) => useDidUpdate(callback, [dep]), {
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initialProps: {dep: 1},
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});
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expect(callback).not.toHaveBeenCalled();
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// Re-render with same dependency
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act(() => {
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rerender({dep: 1});
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});
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expect(callback).not.toHaveBeenCalled();
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// Change dependency
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act(() => {
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rerender({dep: 2});
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});
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expect(callback).toHaveBeenCalledTimes(1);
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});
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});
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