📜  Mockito-行为驱动开发

📅  最后修改于: 2020-12-06 10:17:29             🧑  作者: Mango


行为驱动开发是编写测试的样式使用给定的格式的测试方法。 Mockito提供了特殊的方法。看一下下面的代码片段。

//Given
given(calcService.add(20.0,10.0)).willReturn(30.0);

//when
double result = calcService.add(20.0,10.0);

//then
Assert.assertEquals(result,30.0,0);         

在这里,我们使用给定的BDDMockito类方法,而不是when方法。

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。

文件:MathApplicationTester.java

package com.tutorialspoint.mock;

import static org.mockito.BDDMockito.*;

import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
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(){

      //Given
      given(calcService.add(20.0,10.0)).willReturn(30.0);

      //when
      double result = calcService.add(20.0,10.0);

      //then
      Assert.assertEquals(result,30.0,0);   
   }
}

步骤4-执行测试用例

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