問題描述

我正在使用 PowerMock 編寫單元測試，模擬一些實用程序類的行為.為測試類定義一次行為(通過@BeforeClass 注解)原因:

I'm writing unit tests using PowerMock, mocking behaviour of some util classes. Defining behaviour once for test class (by @BeforeClass annotation) causes:

• 第一次測試調用以返回模擬值
• 第二次測試調用返回真正的方法返回值

示例代碼:

import org.junit.Assert;
import org.junit.BeforeClass;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.powermock.api.mockito.PowerMockito;
import org.powermock.core.classloader.annotations.PrepareForTest;
import org.powermock.modules.junit4.PowerMockRunner;

@RunWith(PowerMockRunner.class)
@PrepareForTest( {A.class, B.class})
public class TestMockedMethods {

private static B b;

@BeforeClass
public static void setUp() {
    PowerMockito.mockStatic(A.class);
    PowerMockito.when(A.getVal()).thenReturn("X");

    b = PowerMockito.mock(B.class);
    PowerMockito.when(b.getVal()).thenReturn("Y");
}

@Test
public void test1() { // PASS
    Assert.assertEquals("X", A.getVal());
    Assert.assertEquals("Y", b.getVal());
}

@Test
public void test2() { // FAIL
    Assert.assertEquals("X", A.getVal()); // actual="A"
    Assert.assertEquals("Y", b.getVal()); // actual="B"
}

}
class A {
  static String getVal() {
    return "A";
  }
}
class B {
  String getVal() {
    return "B";
  }
}

知道第二次測試失敗的原因嗎?

Any ideas why second test is failing?

推薦答案

PowerMockito.mockStatic(...)方法調用MockCreator.mock(...).此方法注冊一個 Runnable，將在 每次測試后執行:

The method PowerMockito.mockStatic(...) invokes MockCreator.mock(...). This method regsiters a Runnable that will be executed after each test :

MockRepository.addAfterMethodRunner(new MockitoStateCleaner());

這個runnable清除了Mockito的內部狀態:

This runnable cleans the internal state of Mockito :

private static class MockitoStateCleaner implements Runnable {
    public void run() {
        clearMockProgress();
        clearConfiguration();
    }

    private void clearMockProgress() {
        clearThreadLocalIn(ThreadSafeMockingProgress.class);
    }

    private void clearConfiguration() {
        clearThreadLocalIn(GlobalConfiguration.class);
    }

    private void clearThreadLocalIn(Class<?> cls) {
        Whitebox.getInternalState(cls, ThreadLocal.class).set(null);
        final Class<?> clazz = ClassLoaderUtil.loadClass(cls, ClassLoader.getSystemClassLoader());
        Whitebox.getInternalState(clazz, ThreadLocal.class).set(null);
    }
}

所以你應該在每次測試之前執行你的設置.

So you should execute your setUp before each test.

@Before
public void setUp() {
    PowerMockito.mockStatic(A.class);
    PowerMockito.when(A.getVal()).thenReturn("X");

    b = PowerMockito.mock(B.class);
    PowerMockito.when(b.getVal()).thenReturn("Y");
}

這篇關于每次使用 PowerMock 進行測試后，模擬行為都會重置的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！