(译) 08-Mockito-预期的调用次数

Mockito 对可对特定方法进行的调用数检查。假设 MathApplication 只调用 CalculatorService. serviceUsed () 方法一次, 则它不应该能够调用 CalculatorService. serviceUsed () 多余一次。

//add the behavior of calc service to add two numbers
when(calcService.add(10.0,20.0)).thenReturn(30.00);

//limit the method call to 1, no less and no more calls are allowed
verify(calcService, times(1)).add(10.0, 20.0);

创建 CalculatorService 接口, 如下所示。

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);
}

例如

步骤1−创建一个 CalculatorService 接口, 以提供数学函数

文件: CalculatorService. java

/**
 * 计算相关服务
 */
public interface CalculatorService {
    /**
     * 加法
     *
     * @param input1
     * @param input2
     * @return
     */
    public double add(double input1, double input2);

    /**
     * 减法
     *
     * @param input1
     * @param input2
     * @return
     */
    public double subtract(double input1, double input2);

    /**
     * 乘法
     *
     * @param input1
     * @param input2
     * @return
     */
    public double multiply(double input1, double input2);

    /**
     * 除法
     *
     * @param input1
     * @param input2
     * @return
     */
    public double divide(double input1, double input2);
}

步骤2−创建一个 JAVA 类来表示 MathApplication

文件: MathApplication. java

/**
 * 数学应用
 */
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);
    }
}

步骤3−测试 MathApplication 类

让我们测试 MathApplication 类, 通过注入 calculatorService 的Mock。Mock将由 Mockito 创建。

文件: MathApplicationTester. java

import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.never;

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);

        //add the behavior of calc service to subtract two numbers
        when(calcService.subtract(20.0,10.0)).thenReturn(10.00);

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

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

        //default call count is 1
        verify(calcService).subtract(20.0, 10.0);

        //check if add function is called three times
        verify(calcService, times(3)).add(10.0, 20.0);

        //verify that method was never called on a mock
        verify(calcService, never()).multiply(10.0,20.0);
    }
}

步骤4−执行测试用例

在C: \ > Mockito_WORKSPACE中创建名为 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TestRunner以查看结果−

C:\Mockito_WORKSPACE>java TestRunner

验证输出。

true

翻译自：https://www.tutorialspoint.com/mockito/mockito_expecting_calls.htm