Mockito mock record

Contents

Introduction

This article looks at how to mock a Record in Java. Mockito 5 made this very easy. Using Mockito 5 you can mock a Record as you would mock any other class. If you are using Mockito 4, you need to enable the mock-maker-inline to mock Records.

Setup using Mockito 5

Mockito 5 has the mock-maker-inline enabled by default. When using Mockito version 5 or higher, you don't have to add a new dependency or add a text file to the test resources. Mocking records will work out of the box.

The maven dependency for mockito 5:

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<dependency>
    <groupId>org.mockito</groupId>
    <artifactId>mockito-core</artifactId>
    <version>5.0.0</version>
    <scope>test</scope>
</dependency>

Setup using Mockito 4

If you are already using mockito 4 and can't upgrade, you need to enable the mock-maker-inline first. There are two ways to do so: by adding a dependency or by creating a file.

Option 1: Mock maker inline dependency

Add this dependency in your pom.xml to enable Mockito's Mock maker inline. We need the Mock maker inline to mock constructors.

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<dependency>
    <groupId>org.mockito</groupId>
    <artifactId>mockito-inline</artifactId>
    <version>4.2.0</version>
    <scope>test</scope>
</dependency>

Option 2: Adding a file to enable the Mock maker inline

If you don't want to or can't add a dependency, you can also use a file to enable the mock maker inline. Create a resources directory in your test directory if you do not have one already. Inside the resources create the directory mockito-extensions and in that directory the file org.mockito.plugins.MockMaker. The complete path with file should look like this: src/test/resources/mockito-extensions/org.mockito.plugins.MockMaker.

in the file org.mockito.plugins.MockMaker paste this text mock-maker-inline, now the mock maker is available during tests.

Testing code

The following piece of code is the Record we are going to mock inside the testing class.

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public record Person(String name, String lastname) {

    public String getFullName(){
        return this.name + " " + this.lastname;
    }
}

With the mock maker inline enabled, which is the default in Mockito 5. We can mock the record class in the test method. In the following example, we have a test method that creates two mocks of the Record Person.

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import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.*;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

public class TestClass {
    
    @Test
    void mockingRecord(){

        // Given
        Person david = mock(Person.class);
        // Mockito 4.9.0 and higher don't need to specify the class
        Person john = mock();

        when(david.getFullName()).thenReturn("David Vlijmincx");

        // When
        String fullName = david.getFullName();

        // Then
        assertEquals("David Vlijmincx",fullName);
    }

}

Conclusion

In this post, we enabled the inline mock maker to mock constructors. We saw that with Mockito version 5, we no longer need to enable the mock-maker-inline ourselves because it is enabled by default. With Mockito 4, we need to enable the mock-maker-inline before we can write our tests. In the last example, we saw how to mock a Record in Java with Mockito.