JMockitを使ってprivateメソッドをモックにしてみた話

ユニットテスト書いてて、関係ないprivateメソッド通りたくないな〜と思ってググってたらJMockitなるすばらしいものがあったので忘れないうちに！

まず、
Maven Repository: org.jmockit » jmockitからpom.xmlにjMockitを追加！

<dependency>
    <groupId>org.jmockit</groupId>
    <artifactId>jmockit</artifactId>
    <version>1.30</version>
</dependency>

JmockitSample.class

package com.example;

public class JmockitSample {
	public static void main(String[] args){
		System.out.println(new JmockitSample().methodPublic());
		System.out.println(methodPublicStatic());
		System.out.println(new JmockitSample().callPrivateMethod());
		System.out.println(callPrivateStaticMethod());
	}

	public String methodPublic() {
		return "methodPublic";
	}

	public static String methodPublicStatic() {
		return "methodPublicStatic";
	}

	public String callPrivateMethod(){
		return new JmockitSample().methodPrivate();
	}

	private String methodPrivate() {
		return "methodPrivate";
	}

	public String callPrivateMethodTwoArgs(){
		return new JmockitSample().methodPrivate("TEST", 1);
	}

	private String methodPrivate(String value, Integer no) {
		return value + no;
	}

	public static String callPrivateStaticMethod(){
		return JmockitSample.methodPrivateStatic();
	}
	private static String methodPrivateStatic() {
		return "methodPrivateStatic";
	}

	public void callPrivateVoidMethod(){
		new JmockitSample().voidMethodPrivate(1);
	}

	private void voidMethodPrivate(int no) {}
}

JmockitSampleTest.java

package com.example;

import mockit.Mock;
import mockit.MockUp;
import org.junit.Before;
import org.junit.Test;
import org.mockito.InjectMocks;

import static org.junit.Assert.assertEquals;
import static org.mockito.MockitoAnnotations.initMocks;

public class JmockitSampleTest {

	@InjectMocks
	JmockitSample jmockitSample;

	private int sum = 0;

	@Before
	public void setup() {
		initMocks(this);
	}

	@Test
	public void mockTest(){

		new MockUp<JmockitSample>() {
			@Mock
			private String methodPrivate() {
				return "mocked methodPrivate";
			}

			@Mock
			private String methodPrivate(String value, Integer no) {
				return "mocked methodPrivate two args";
			}

			@Mock
			private String methodPrivateStatic() {
				return "mocked methodPrivateStatic";
			}

			@Mock
			private void voidMethodPrivate(int no) {
				sum += 5;
			}
		};

		assertEquals(new JmockitSample().methodPublic(), "methodPublic");
		assertEquals(JmockitSample.methodPublicStatic(), "methodPublicStatic");
		assertEquals(new JmockitSample().callPrivateMethod(), "mocked methodPrivate");
		assertEquals(new JmockitSample().callPrivateMethodTwoArgs(), "mocked methodPrivate two args");
		assertEquals(JmockitSample.callPrivateStaticMethod(), "mocked methodPrivateStatic");

		new JmockitSample().callPrivateVoidMethod();
		assertEquals(5, sum);
	}
}

privateメソッドのモックができましたー