Initialize Mockito Tests with JUnit
This example show you how to initialize mockito tests using annotations. First we can use the MockitoAnnotations.initMocks(this) method to explicitly initialize the annotated mocks. The MockitoJUnitRunner JUnit runner uses the MockitoAnnotations.initMocks(this) method to initialize the annotated mocks.
Dependencies
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.memorynotfound.test.mockito</groupId>
<artifactId>initialize-tests</artifactId>
<version>1.0.0-SNAPSHOT</version>
<name>MOCKITO - ${project.artifactId}</name>
<url>https://memorynotfound.com</url>
<properties>
<mockito.version>1.10.19</mockito.version>
<junit.version>4.12</junit.version>
</properties>
<dependencies>
<dependency>
<groupId>org.mockito</groupId>
<artifactId>mockito-all</artifactId>
<version>${mockito.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>${junit.version}</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>Initialize Mockito Tests with MockitoAnnotations
The MockitoAnnotations.initMocks(this) method is called in the @Before method. This method initializes the annotated mocks.
package com.memorynotfound.test;
import org.junit.Before;
import org.junit.Test;
import org.mockito.MockitoAnnotations;
import org.mockito.Spy;
import java.util.ArrayList;
import java.util.List;
import static org.junit.Assert.assertEquals;
import static org.mockito.Mockito.doReturn;
public class InitializeBeforeTest {
@Spy
List<String> messages = new ArrayList<String>();
@Before
public void setUp(){
MockitoAnnotations.initMocks(this);
}
@Test
public void testSpyOnList() {
String message = "Initialize Mockito Tests with MockitoAnnotations";
doReturn(message).when(messages).get(13);
assertEquals(message, messages.get(13));
}
}Initialize Mockito Tests with MockitoJUnitRunner
When using JUnit we can also register a MockitoJUnitRunner to the class. This method calls the MockitoAnnotations.initMocks(this) method to initialize the annotated mocks.
package com.memorynotfound.test;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Spy;
import org.mockito.runners.MockitoJUnitRunner;
import java.util.ArrayList;
import java.util.List;
import static org.junit.Assert.assertEquals;
import static org.mockito.Mockito.doReturn;
@RunWith(MockitoJUnitRunner.class)
public class InitializeJUnitRunnerTest {
@Spy
List<String> messages = new ArrayList<String>();
@Test
public void testSpyOnList() {
String message = "Initialize Mockito Tests with MockitoJUnitRunner";
doReturn(message).when(messages).get(74);
assertEquals(message, messages.get(74));
}
}
