Easymock 简明教程

EasyMock - createNiceMock

EasyMock.createNiceMock() 创建一个模拟，并为模拟的每个方法设置默认实现。如果使用了 EasyMock.createMock()，那么调用模拟方法会抛出断言错误。

Syntax

calcService = EasyMock.createNiceMock(CalculatorService.class);

Example

Step 1: Create an interface called CalculatorService to provide mathematical functions.

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);
}

Step 2: Create a JAVA class to represent 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);
   }
}

Step 3: Test the MathApplication class

让我们测试 MathApplication 类，并注入一个 calculatorService 模拟。模拟将由 EasyMock 创建。

这里我们通过 expect() 添加了一个模拟方法调用 add()。然而，在测试期间，我们还调用了 subtract() 和其他方法。当我们使用 EasyMock.createNiceMock() 创建模拟对象时，可以使用具有默认值的默认实现。

文件: MathApplicationTester.java

import org.easymock.EasyMock;
import org.easymock.EasyMockRunner;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;

@RunWith(EasyMockRunner.class)
public class MathApplicationTester {
   private MathApplication mathApplication;
   private CalculatorService calcService;

   @Before
   public void setUp(){
      mathApplication = new MathApplication();
      calcService = EasyMock.createNiceMock(CalculatorService.class);
      mathApplication.setCalculatorService(calcService);
   }
   @Test
   public void testCalcService(){
      //add the behavior to add numbers
      EasyMock.expect(calcService.add(20.0,10.0)).andReturn(30.0);

      //activate the mock
      EasyMock.replay(calcService);

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

      //test the subtract functionality
      Assert.assertEquals(mathApplication.subtract(20.0, 10.0),0.0,0);

      //test the multiply functionality
      Assert.assertEquals(mathApplication.divide(20.0, 10.0),0.0,0);

      //test the divide functionality
      Assert.assertEquals(mathApplication.multiply(20.0, 10.0),0.0,0);

      //verify call to calcService is made or not
      EasyMock.verify(calcService);
   }
}

Step 4: Execute test cases

在 *C:\> EasyMock_WORKSPACE * 中创建一个名为 TestRunner 的 Java 类文件来执行测试用例。

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:\EasyMock_WORKSPACE>javac MathApplicationTester.java现在运行测试运行器以查看结果 −C:\EasyMock_WORKSPACE>java TestRunner

Output

验证输出。

true