@SpringBootTest for integration tests - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What does @SpringBootTest do in a test class?

Consider a test class annotated with @SpringBootTest. What is the main effect of this annotation when running the test?

A It loads the full Spring application context for integration testing.

B It only loads the web layer components without starting the full context.

C It mocks all Spring beans automatically to isolate the test.

D It disables Spring context loading and runs tests as plain unit tests.

💡 Hint

Think about whether the whole app context is started or just parts of it.

@SpringBootTest tells Spring Boot to start the entire application context, allowing integration tests to run with all beans loaded as in a real app.

📝 Syntax

intermediate

Which @SpringBootTest property controls the web environment?

Look at these options for @SpringBootTest(webEnvironment = ...). Which one starts the embedded server on a random port?

A WebEnvironment.DEFINED_PORT

B WebEnvironment.MOCK

C WebEnvironment.NONE

D WebEnvironment.RANDOM_PORT

💡 Hint

Random port means the server starts on any free port to avoid conflicts.

WebEnvironment.RANDOM_PORT starts the embedded server on a random free port, useful for real HTTP integration tests.

🔧 Debug

advanced

Why does this @SpringBootTest fail to inject a bean?

Given this test class:

  @SpringBootTest
  public class MyServiceTest {
    @Autowired
    private MyService myService;

    @Test
    void testService() {
      assertNotNull(myService);
    }
  }

The test fails because myService is null. What is the likely cause?

A The <code>@SpringBootTest</code> annotation is missing the <code>classes</code> attribute specifying the config.

B The <code>MyService</code> bean is not annotated with <code>@Service</code> or <code>@Component</code>.

C The <code>myService</code> field should be static for injection to work.

D The test class is missing <code>@RunWith(SpringRunner.class)</code> annotation.

💡 Hint

Check if the bean is properly registered in the Spring context.

If MyService is not annotated with @Service or @Component, Spring will not create a bean for it, so injection fails.

❓ state_output

advanced

What is the output of this @SpringBootTest with properties override?

Consider this test class:

@SpringBootTest(properties = {"app.feature.enabled=false"})
public class FeatureTest {

  @Value("${app.feature.enabled}")
  private boolean featureEnabled;

  @Test
  void testFeatureFlag() {
    System.out.println(featureEnabled);
  }
}

What will be printed when the test runs?

A false

B true

C null

D Throws an exception due to missing property

💡 Hint

Properties in @SpringBootTest override application properties.

The properties attribute sets app.feature.enabled to false, so featureEnabled is false.

🧠 Conceptual

expert

Why prefer @SpringBootTest over @WebMvcTest for full integration tests?

Which reason best explains why @SpringBootTest is preferred over @WebMvcTest for full integration testing?

A @WebMvcTest disables Spring Security, so it cannot test secured endpoints.

B @SpringBootTest runs tests faster because it loads fewer beans than @WebMvcTest.

C @SpringBootTest loads the entire application context including services and repositories, enabling end-to-end testing.

D @WebMvcTest automatically mocks all dependencies, so it cannot test real database interactions.

💡 Hint

Think about how much of the app is loaded and tested.

@SpringBootTest loads the full app context, allowing tests to cover all layers including database and services, unlike @WebMvcTest which only loads web layer beans.