Mockito-回调 - 芒果文档

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📜 Mockito-回调

📅 最后修改于: 2020-12-06 10:16:20 🧑 作者: Mango

Mockito提供了一个Answer接口，该接口允许使用通用接口进行存根。

句法

//add the behavior to add numbers
when(calcService.add(20.0,10.0)).thenAnswer(new Answer() {
   @Override
   public Double answer(InvocationOnMock invocation) throws Throwable {
      //get the arguments passed to mock
      Object[] args = invocation.getArguments();
      //get the mock 
      Object mock = invocation.getMock();    
      //return the result
      return 30.0;
   }
});

例

步骤1-创建一个名为CalculatorService的接口以提供数学函数

文件：CalculatorService.java

public interface CalculatorService {
   public double add(double input1, double input2);
   public double subtract(double input1, double input2);
   public double multiply(double input1, double input2);
   public double divide(double input1, double input2);
}

第2步-创建一个JAVA类来表示MathApplication

文件：MathApplication.java

public class MathApplication {
   private CalculatorService calcService;

   public void setCalculatorService(CalculatorService calcService){
      this.calcService = calcService;
   }
   
   public double add(double input1, double input2){
      return calcService.add(input1, input2);        
   }
   
   public double subtract(double input1, double input2){
      return calcService.subtract(input1, input2);
   }
   
   public double multiply(double input1, double input2){
      return calcService.multiply(input1, input2);
   }
   
   public double divide(double input1, double input2){
      return calcService.divide(input1, input2);
   }
}

第3步-测试MathApplication类

让我们通过向其注入一个CalculatorService模拟来测试MathApplication类。模拟将由Mockito创建。

在这里，我们通过when()向模拟对象添加了一个模拟方法调用add()。但是，在测试过程中，我们在调用add()之前先调用了减去()。当我们使用Mockito.createStrictMock()创建模拟对象时，方法的执行顺序很重要。

文件：MathApplicationTester.java

import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;
import static org.mockito.Mockito.inOrder;

import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.InOrder;
import org.mockito.runners.MockitoJUnitRunner;

// @RunWith attaches a runner with the test class to initialize the test data
@RunWith(MockitoJUnitRunner.class)
public class MathApplicationTester {
    
   private MathApplication mathApplication;
   private CalculatorService calcService;

   @Before
   public void setUp(){
      mathApplication = new MathApplication();
      calcService = mock(CalculatorService.class);
      mathApplication.setCalculatorService(calcService);
   }

   @Test
   public void testAdd(){

      //add the behavior to add numbers
      when(calcService.add(20.0,10.0)).thenAnswer(new Answer() {

         @Override
         public Double answer(InvocationOnMock invocation) throws Throwable {
            //get the arguments passed to mock
            Object[] args = invocation.getArguments();
            
            //get the mock 
            Object mock = invocation.getMock();    
            
            //return the result
            return 30.0;
         }
      });

      //test the add functionality
      Assert.assertEquals(mathApplication.add(20.0, 10.0),30.0,0);
   }
}

步骤4-执行测试用例

在C：\> Mockito_WORKSPACE中创建一个名为TestRunner的Java类文件以执行测试用例。

文件：TestRunner.java

import org.junit.runner.JUnitCore;
import org.junit.runner.Result;
import org.junit.runner.notification.Failure;

public class TestRunner {
   public static void main(String[] args) {
      Result result = JUnitCore.runClasses(MathApplicationTester.class);
      
      for (Failure failure : result.getFailures()) {
         System.out.println(failure.toString());
      }
      
      System.out.println(result.wasSuccessful());
   }
}

步骤5-验证结果

使用javac编译器编译类，如下所示：

C:\Mockito_WORKSPACE>javac CalculatorService.java MathApplication.
   java MathApplicationTester.java TestRunner.java

现在运行测试运行器以查看结果-

C:\Mockito_WORKSPACE>java TestRunner

验证输出。

true