未完成的刺激感

Question

我是Android的单位测试中的新手。我的问题是我有一个从DP获得像素的帮助人课。该代码效果很好，并具有一种静态方法。当我想为此课程写测试时，我会给这个错误：

org.mockito.exceptions.misusing.UnfinishedStubbingException: 
Unfinished stubbing detected here:
-> at com.sooran.emdad.ExampleUnitTest.setup(ExampleUnitTest.java:70)
E.g. thenReturn() may be missing.
Examples of correct stubbing:
when(mock.isOk()).thenReturn(true);
when(mock.isOk()).thenThrow(exception);
doThrow(exception).when(mock).someVoidMethod();
Hints:
1. missing thenReturn()
2. you are trying to stub a final method, which is not supported
3: you are stubbing the behaviour of another mock inside before 'thenReturn' 
instruction is completed

at com.sooran.emdad.Util.DpUtil2.toPixels(DpUtil2.java:10)
at com.sooran.emdad.ExampleUnitTest.setup(ExampleUnitTest.java:70)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at 
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:24)
    at org.mockito.internal.runners.DefaultInternalRunner$1$1.evaluate(DefaultInternalRunner.java:44)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.mockito.internal.runners.DefaultInternalRunner$1.run(DefaultInternalRunner.java:74)
    at org.mockito.internal.runners.DefaultInternalRunner.run(DefaultInternalRunner.java:80)
    at org.mockito.internal.runners.StrictRunner.run(StrictRunner.java:39)
    at org.mockito.junit.MockitoJUnitRunner.run(MockitoJUnitRunner.java:163)
    at org.mockito.runners.MockitoJUnitRunner.run(MockitoJUnitRunner.java:53)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

这是我的班级：

public class DpUtil2 {
public static int toPixels(int dp, Context context) {
    DisplayMetrics metrics = context.getResources().getDisplayMetrics();
    float value=TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp, metrics);
    return (int) value;
}

这是我的测试代码：

@RunWith(MockitoJUnitRunner.class)
public class ExampleUnitTest {
@Mock
Context context;
@Mock
Resources resources;
@Mock
DisplayMetrics displayMetrics=new DisplayMetrics();
@Mock
DpUtil2 dpUtil;
@Test
public void addition_isCorrect() {
    assertEquals(4, 2 + 2);
}
@Test
public void dpTest(){
    assertEquals(dpUtil.toPixels(64,context),168);
}
@Before
public void setup(){
    displayMetrics.setToDefaults();
    displayMetrics.density=2.625f;
    displayMetrics.widthPixels=1080;
    displayMetrics.heightPixels=1794;
    displayMetrics.scaledDensity=2.625f;
    displayMetrics.xdpi=422.03f;
    displayMetrics.ydpi=424.069f;
    displayMetrics.densityDpi=420;
    int x=168;
    doReturn(resources).when(context).getResources();
    doReturn(displayMetrics).when(resources).getDisplayMetrics();
    doReturn(x).when(dpUtil).toPixels(64,context);
    }

我可以通过删除第三次返回正确通过测试但是为什么第三回报给出此错误

Answer 1

好吧，要测试静态方法，您需要使用PowerMock，我使用了您的样本并修改了。

   package com.sample.mass;
    import android.content.Context;
    import android.content.res.Resources;
    import android.util.DisplayMetrics;
    import org.junit.Assert;
    import org.junit.Before;
    import org.junit.Test;
    import org.junit.runner.RunWith;
    import org.mockito.Mock;
    import org.mockito.Mockito;
    import org.mockito.MockitoAnnotations;
    import org.powermock.api.mockito.PowerMockito;
    import org.powermock.core.classloader.annotations.PrepareForTest;
    import org.powermock.modules.junit4.PowerMockRunner;
@RunWith(PowerMockRunner.class)
@PrepareForTest({DpUtil2.class})
public class DpUtil2Test {

    private DpUtil2 mDpUtil2;
    @Mock
    Context mContext;
    @Mock
    Resources mResources;
    @Mock
    DisplayMetrics mDisplayMetrics;

    private int dp = 20;
    @Before
    public void setup() {
        MockitoAnnotations.initMocks(this);
        Mockito.when(mResources.getDisplayMetrics()).thenReturn(mDisplayMetrics);
        Mockito.when(mContext.getResources()).thenReturn(mResources);
    }
    @Test
    public void testToPixels() throws Exception {
        System.out.println("yes");
        PowerMockito.mockStatic(DpUtil2.class);
        PowerMockito.when(DpUtil2.toPixels(dp, mContext)).thenReturn(dp);
        int actualResult = DpUtil2.toPixels(dp, mContext);
        //expected, actual
        Assert.assertEquals(dp, actualResult);
        PowerMockito.verifyStatic(DpUtil2.class);
        DpUtil2.toPixels(dp, mContext);
        System.out.println("-----------we are done--------------------");
    }
}

并将其在gradle中使用，

 testImplementation 'org.mockito:mockito-core:2.2.0'
    testImplementation 'org.powermock:powermock-core:1.7.1'
    testImplementation 'org.powermock:powermock-module-junit4:1.7.1'
    testImplementation 'org.powermock:powermock-api-mockito2:1.7.1'