Spring Boot @SpringBootTest in JUnit - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the @SpringBootTest annotation in Spring Boot testing?

@SpringBootTest tells Spring Boot to start the full application context for integration testing. It helps test how components work together in a real environment.

intermediate

How does @SpringBootTest differ from unit testing annotations like @WebMvcTest?

@SpringBootTest loads the entire application context, while @WebMvcTest loads only web layer components for focused controller tests.

intermediate

What does the webEnvironment attribute in @SpringBootTest control?

It controls how the embedded web server is started during tests. Options include MOCK (no real server), RANDOM_PORT, DEFINED_PORT, and NONE.

beginner

Why should you avoid using @SpringBootTest for simple unit tests?

Because it loads the full application context, which is slow and resource-heavy. For simple unit tests, use lighter annotations or plain JUnit tests.

intermediate

How can you use @SpringBootTest to run tests with a specific profile?

<p>You can add <code>@ActiveProfiles("test")</code> on the test class to activate the <code>test</code> profile during the test run.</p>

What does @SpringBootTest do when placed on a test class?

A Loads the full Spring application context for integration testing

B Mocks all dependencies automatically

C Runs only unit tests without Spring context

D Starts only the web layer for testing

@SpringBootTest loads the full application context to test integration of components.

Which webEnvironment option starts a real server on a random port during @SpringBootTest?

A MOCK

B DEFINED_PORT

C NONE

D RANDOM_PORT

RANDOM_PORT starts an embedded server on a random port for real HTTP testing.

Which annotation activates a specific Spring profile during a @SpringBootTest?

A @ActiveProfiles

B @TestProfile

C @Profile

D @SpringProfile

@ActiveProfiles sets the active profile(s) for the test context.

Why might @SpringBootTest tests run slower than unit tests?

A Because they run in a separate JVM

B Because they use more CPU-intensive assertions

C Because they load the full Spring application context

D Because they skip dependency injection

Loading the full application context takes more time and resources, slowing tests.

Which annotation is best for testing only Spring MVC controllers without loading the full context?

A @SpringBootTest

B @WebMvcTest

C @DataJpaTest

D @RestControllerTest

@WebMvcTest loads only web layer components for focused controller tests.

Explain what @SpringBootTest does and when you should use it.

Think about testing the whole app versus parts.

Describe how to configure @SpringBootTest to run tests with a specific Spring profile and why this is useful.

Profiles help customize app behavior for tests.