| 1 | /** |
| 2 | * Copyright (c) Meta Platforms, Inc. and affiliates. |
| 3 | * |
| 4 | * This source code is licensed under the MIT license found in the |
| 5 | * LICENSE file in the root directory of this source tree. |
| 6 | * |
| 7 | * @flow |
| 8 | */ |
| 9 | |
| 10 | describe('Bridge', () => { |
| 11 | let Bridge; |
| 12 | |
| 13 | beforeEach(() => { |
| 14 | Bridge = require('react-devtools-shared/src/bridge').default; |
| 15 | }); |
| 16 | |
| 17 | // @reactVersion >=16.0 |
| 18 | it('should shutdown properly', () => { |
| 19 | const wall = { |
| 20 | listen: jest.fn(() => () => {}), |
| 21 | send: jest.fn(), |
| 22 | }; |
| 23 | const bridge = new Bridge(wall); |
| 24 | const shutdownCallback = jest.fn(); |
| 25 | bridge.addListener('shutdown', shutdownCallback); |
| 26 | |
| 27 | // Check that we're wired up correctly. |
| 28 | bridge.send('reloadAppForProfiling'); |
| 29 | jest.runAllTimers(); |
| 30 | expect(wall.send).toHaveBeenCalledWith('reloadAppForProfiling', undefined); |
| 31 | |
| 32 | // Should flush pending messages and then shut down. |
| 33 | wall.send.mockClear(); |
| 34 | bridge.send('update', '1'); |
| 35 | bridge.send('update', '2'); |
| 36 | bridge.shutdown(); |
| 37 | jest.runAllTimers(); |
| 38 | expect(wall.send).toHaveBeenCalledWith('update', '1'); |
| 39 | expect(wall.send).toHaveBeenCalledWith('update', '2'); |
| 40 | expect(wall.send).toHaveBeenCalledWith('shutdown', undefined); |
| 41 | expect(shutdownCallback).toHaveBeenCalledTimes(1); |
| 42 | |
| 43 | // Using a Bridge after shutdown is a lifecycle error. |
| 44 | wall.send.mockClear(); |
| 45 | expect(() => bridge.send('should not send')).toThrow( |
| 46 | 'Cannot send a message through a Bridge that has been shut down.', |
| 47 | ); |
| 48 | expect(() => bridge.addListener('event', () => {})).toThrow( |
| 49 | 'Cannot add a listener through a Bridge that has been shut down.', |
| 50 | ); |
| 51 | expect(() => bridge.emit('event')).toThrow( |
| 52 | 'Cannot emit an event through a Bridge that has been shut down.', |
| 53 | ); |
| 54 | expect(() => bridge.shutdown()).toThrow( |
| 55 | 'Cannot shut down through a Bridge that has been shut down.', |
| 56 | ); |
| 57 | jest.runAllTimers(); |
| 58 | expect(wall.send).not.toHaveBeenCalled(); |
| 59 | }); |
| 60 | |
| 61 | // @reactVersion >=16.0 |
| 62 | it('validates messages received from the wall', () => { |
| 63 | let wallListener: ((message: mixed) => void) | null = null; |
| 64 | const wall = { |
| 65 | listen: jest.fn(listener => { |
| 66 | wallListener = listener; |
| 67 | return () => {}; |
| 68 | }), |
| 69 | send: jest.fn(), |
| 70 | }; |
| 71 | const bridge = new Bridge(wall); |
| 72 | const listener = jest.fn(); |
| 73 | bridge.addListener('event', listener); |
| 74 | |
| 75 | const dispatch = (message: mixed) => { |
| 76 | if (wallListener === null) { |
| 77 | throw new Error('Expected the Bridge to subscribe to the wall.'); |
| 78 | } |
| 79 | wallListener(message); |
| 80 | }; |
| 81 | |
| 82 | // Walls may share their transport with unrelated or legacy messages. |
| 83 | dispatch(null); |
| 84 | dispatch({type: 'event'}); |
| 85 | expect(listener).not.toHaveBeenCalled(); |
| 86 | |
| 87 | expect(() => dispatch({event: 123})).toThrow( |
| 88 | 'Bridge event names must be non-empty strings.', |
| 89 | ); |
| 90 | expect(() => dispatch({event: ''})).toThrow( |
| 91 | 'Bridge event names must be non-empty strings.', |
| 92 | ); |
| 93 | |
| 94 | dispatch({event: 'event', payload: 123}); |
| 95 | expect(listener).toHaveBeenCalledWith(123); |
| 96 | }); |
| 97 | |
| 98 | // @reactVersion >=16.0 |
| 99 | it('requires Wall.listen to return a cleanup function', () => { |
| 100 | expect( |
| 101 | () => |
| 102 | new Bridge({ |
| 103 | listen: () => undefined, |
| 104 | send: jest.fn(), |
| 105 | }), |
| 106 | ).toThrow('Wall.listen() must return an unlisten function.'); |
| 107 | }); |
| 108 | |
| 109 | // @reactVersion >=16.0 |
| 110 | it('flushes pending messages when wall cleanup throws', () => { |
| 111 | const expectedError = new Error('Failed to unsubscribe'); |
| 112 | const wall = { |
| 113 | listen: jest.fn(() => () => { |
| 114 | throw expectedError; |
| 115 | }), |
| 116 | send: jest.fn(), |
| 117 | }; |
| 118 | const bridge = new Bridge(wall); |
| 119 | |
| 120 | bridge.send('update', 'value'); |
| 121 | expect(() => bridge.shutdown()).toThrow(expectedError); |
| 122 | expect(wall.send).toHaveBeenCalledWith('update', 'value'); |
| 123 | expect(wall.send).toHaveBeenCalledWith('shutdown', undefined); |
| 124 | }); |
| 125 | }); |