差異處
這裏顯示兩個版本的差異處。
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java:junit:powermock:mockconsctructor [2013/02/24 23:01] 127.0.0.1 外部編輯 |
java:junit:powermock:mockconsctructor [2023/06/25 09:48] |
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| - | {{tag>java powermock}} | ||
| - | ====== Mock Constructor ====== | ||
| - | ===== Problem ===== | ||
| - | 在[[.:mocksystemexit|Mock System.exit]]中，我們有遇到exception path該如何測的問題。第一個方法是將new Example抽出為static的createExample，再用powermock去mock它 (記得在efficiency java中看過，它建議你將new Example寫成createExample的method去產生instance)；第二個方法是直接使用powermock的mock construcor功能。無論如何，在mock出example instance後，都需要再mock doSomething讓它拋出exception。在這我使用第二個方法為大家做說明。 | ||
| - | <code java> | ||
| - | package org.tonylin.powermock; | ||
| - | |||
| - | public class Example { | ||
| - | |||
| - | public Example(){ | ||
| - | |||
| - | } | ||
| - | |||
| - | public void doSomething(){ | ||
| - | |||
| - | } | ||
| - | |||
| - | public static void main(String[] args) { | ||
| - | try { | ||
| - | new Example().doSomething(); | ||
| - | } catch( Exception e ){ | ||
| - | System.exit(1); | ||
| - | } finally { | ||
| - | System.exit(0); | ||
| - | } | ||
| - | } | ||
| - | |||
| - | } | ||
| - | </code> | ||
| - | ===== How to solve? ===== | ||
| - | 首先我們需mock System.exit為1的情況，接著透過PowerMock.createMockAndExpectNew(Example.class)讓new Example都會產生這個mock object。在example.doSomething()後，透過PowerMock.expectLastCall().andStubThrow去拋出RuntimeException，這能夠讓main程式出現exception情況。最後reply再執行。 | ||
| - | <code java> | ||
| - | @RunWith(PowerMockRunner.class) | ||
| - | @PrepareForTest({Example.class}) | ||
| - | public class TestExample { | ||
| - | @Test | ||
| - | public void testMainWithException() throws Exception{ | ||
| - | // mock System.exit | ||
| - | PowerMock.mockStatic(System.class); | ||
| - | System.exit(1); | ||
| - | PowerMock.expectLastCall().times(1); | ||
| - | |||
| - | // mock constructor | ||
| - | Example example = PowerMock.createMockAndExpectNew(Example.class); | ||
| - | example.doSomething(); | ||
| - | PowerMock.expectLastCall().andStubThrow(new RuntimeException()); | ||
| - | |||
| - | PowerMock.replayAll(); | ||
| - | |||
| - | Example.main(new String[0]); | ||
| - | } | ||
| - | } | ||
| - | </code> | ||
| - | |||
| - | 如果你使用的情況是Class A去new Class B，而你要mock Class B，要記得把Class A加到**PrepareForTest**中喔!\\ | ||
| - | |||
| - | PowerMock.createMockAndExpectNew(Example.class)的寫法，也可改為這種寫法: | ||
| - | <code java> | ||
| - | Example example = PowerMock.createNiceMock(Example.class); | ||
| - | PowerMock.expectNew(Example.class).andReturn(example); | ||
| - | </code> | ||
| - | 但我想沒人會想做多寫一行的事情吧? (一行也是生產力嗎?) | ||
| - | |||
| - | ===== Reference ===== | ||
| - | * [[http://code.google.com/p/powermock/wiki/MockConstructor|MockConstructor]] | ||
