Mockito verifyNoMoreInteractions Method

The verifyNoMoreInteractions method in Mockito is used to check if there are any unverified interactions on the specified mock objects. This method helps ensure that all interactions with the mocks have been explicitly verified, improving the reliability and accuracy of your tests.

Table of Contents

1. Introduction
2. verifyNoMoreInteractions Method Syntax
3. Examples
   • Basic Usage
   • Verifying Multiple Mocks
4. Real-World Use Case
5. Conclusion

Introduction

Mockito is a popular library in Java for creating and managing mock objects. The verifyNoMoreInteractions method allows you to ensure that all interactions with the specified mock objects have been verified. This is useful for catching unexpected interactions and ensuring that your tests are thorough.

verifyNoMoreInteractions Method Syntax

Checking for Unverified Interactions

static void verifyNoMoreInteractions(Object... mocks)

Checks if any of the given mocks have any unverified interactions.

Parameters:

• mocks: The mock objects to check for unverified interactions.

Returns:

• Nothing. If any unverified interactions are found, an org.mockito.exceptions.verification.NoInteractionsWanted exception is thrown.

Examples

Basic Usage

Verify that there are no unverified interactions on a single mock object.

import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.verifyNoMoreInteractions;
import org.junit.jupiter.api.Test;

public class BasicVerifyNoMoreInteractionsTest {
    @Test
    void testVerifyNoMoreInteractions() {
        UserService mockUserService = mock(UserService.class);
        
        // Perform some interactions
        mockUserService.deleteUser("123");

        // Verify the interaction
        verify(mockUserService).deleteUser("123");

        // Verify that there are no more interactions
        verifyNoMoreInteractions(mockUserService);
    }
}

class UserService {
    public void deleteUser(String userId) {
        // Method implementation
    }
}

Verifying Multiple Mocks

Verify that there are no unverified interactions on multiple mock objects.

import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.verifyNoMoreInteractions;
import org.junit.jupiter.api.Test;

public class MultipleVerifyNoMoreInteractionsTest {
    @Test
    void testVerifyNoMoreInteractionsMultipleMocks() {
        UserService mockUserService = mock(UserService.class);
        NotificationService mockNotificationService = mock(NotificationService.class);
        
        // Perform some interactions
        mockUserService.deleteUser("123");
        mockNotificationService.sendNotification("User 123 deleted");

        // Verify the interactions
        verify(mockUserService).deleteUser("123");
        verify(mockNotificationService).sendNotification("User 123 deleted");

        // Verify that there are no more interactions
        verifyNoMoreInteractions(mockUserService, mockNotificationService);
    }
}

class UserService {
    public void deleteUser(String userId) {
        // Method implementation
    }
}

interface NotificationService {
    void sendNotification(String message);
}

Real-World Use Case

Ensuring No Unintended Calls in Complex Interactions

In a real-world scenario, you might want to ensure that all interactions with your mocks are accounted for, especially in complex tests with multiple interactions. Using verifyNoMoreInteractions, you can catch any unexpected interactions that might indicate a bug in your code.

import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.verifyNoMoreInteractions;
import org.junit.jupiter.api.Test;

interface NotificationService {
    void sendNotification(String message);
}

class UserService {
    private final NotificationService notificationService;

    public UserService(NotificationService notificationService) {
        this.notificationService = notificationService;
    }

    public void deleteUser(String userId) {
        // Perform user deletion logic
        notificationService.sendNotification("User " + userId + " deleted");
    }

    public void addUser(String userId) {
        // Perform user addition logic
        notificationService.sendNotification("User " + userId + " added");
    }
}

public class UserServiceTest {
    @Test
    void testUserServiceInteractions() {
        NotificationService mockNotificationService = mock(NotificationService.class);
        UserService userService = new UserService(mockNotificationService);
        
        // Call methods on UserService
        userService.deleteUser("123");
        userService.addUser("456");

        // Verify the interactions
        verify(mockNotificationService).sendNotification("User 123 deleted");
        verify(mockNotificationService).sendNotification("User 456 added");

        // Verify that there are no more interactions
        verifyNoMoreInteractions(mockNotificationService);
    }
}

In this example, the UserServiceTest class uses Mockito’s verifyNoMoreInteractions method to ensure that there are no unverified interactions with the NotificationService mock. This helps ensure that all expected interactions are verified and no unexpected calls are made.

Conclusion

The verifyNoMoreInteractions method in Mockito is used for ensuring that all interactions with mock objects are explicitly verified. By using verifyNoMoreInteractions, you can catch unexpected interactions and improve the thoroughness and reliability of your tests. This helps ensure that your tests accurately reflect the behavior of your code.