Mockito

Mockito is a testing framework for Java that generates stubs and mocks for dependencies.

Language	Implementation	License	Current Version
Java	Java	MIT License	5.22.0

Table of Contents

• 1 Resources
• 2 Installation
  • 2.1 Maven
  • 2.2 Gradle
• 3 Mocking
• 4 Stubbing

1 Resources

• Official website: Mockito framework site
• Official documentation: Mockito Javadoc

2 Installation

2.1 Maven

This must be added to the pom.xml file:

<dependencies>
    <dependency>
        <groupId>org.mockito</groupId>
        <artifactId>mockito-code</artifactId>
        <version>5.22.0</version>
        <scope>test</scope>
    </dependency>
</dependencies>

2.2 Gradle

This must be added to the build.gradle or build.gradle.kts file:

dependencies {
    testImplementation("org.mockito:mockito-core:5.22.0")
}

3 Mocking

import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.verify;

// create mock objects of classes
List mockedList = mock();

// call methods on mock objects
mockedList.add("one");
mockedList.clear();

// verify that methods in mocks executed as expected
verify(mockedList).add("one");
verify(mockedList).clear();

4 Stubbing

import static org.mockito.Mockito.mock;

// create mock objects of classes
List mockedList = mock();

// create stubs for mock objects
when(mockedList.get(0)).thenReturn("first");

// use created stubs
mockedList.get(0).equals("first");
mockedList.get(100) == null;  // non-created stubs evaluate to null