📜  Mockito-JUnit集成

📅  最后修改于: 2020-12-06 10:12:53             🧑  作者: Mango


在本章中,我们将学习如何将JUnit和Mockito集成在一起。在这里,我们将创建一个数学应用程序,该应用程序使用CalculatorService执行基本的数学运算,例如加法,减法,乘法和除法。

我们将使用Mockito模拟CalculatorService的虚拟实现。另外,我们广泛使用了注释,以展示它们与JUnit和Mockito的兼容性。

下面将逐步讨论该过程。

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

import static org.mockito.Mockito.when;

import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.runners.MockitoJUnitRunner;

// @RunWith attaches a runner with the test class to initialize the test data
@RunWith(MockitoJUnitRunner.class)
public class MathApplicationTester {
    
   //@InjectMocks annotation is used to create and inject the mock object
   @InjectMocks 
   MathApplication mathApplication = new MathApplication();

   //@Mock annotation is used to create the mock object to be injected
   @Mock
   CalculatorService calcService;

   @Test
   public void testAdd(){
      //add the behavior of calc service to add two numbers
      when(calcService.add(10.0,20.0)).thenReturn(30.00);
        
      //test the add functionality
      Assert.assertEquals(mathApplication.add(10.0, 20.0),30.0,0);
   }
}

步骤4-创建要执行以测试案例的类

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

要了解有关JUnit的更多信息,请参考Tutorials Point上的JUnit Tutorial。