When developers run integration and unit tests on their local machines, everything often seems great until they push their code to Jenkins. Suddenly, they face integration or unit test failures that simply didn’t appear locally. This frustrating phenomenon recently occurred for many developers when upgrading to Spring Boot 3.4.0 and migrating Mockito annotations. Specifically, developers encountered unexpected issues with the new @MockitoBean which worked fine locally but failed mysteriously on Jenkins.
Let’s look closely at what might have gone wrong and how to tackle this Jenkins-specific issue.
Background of Current Versions
In modern Java applications, Spring Boot remains a popular choice due to its simplicity and efficient usage. With the recent release of Spring Boot 3.4.0, several changes were introduced. Alongside Spring Boot, many projects use TestNG for handling test suites or the Spring Test module to provide integration testing tools. It’s essential to keep these dependencies updated and correctly configured:
- Spring Boot 3.4.0 (Spring official website)
- TestNG 7.9.0 (TestNG official site)
- Spring Test 6.x latest (Spring Test)
Updating these dependencies might sometimes introduce subtle issues—such as the current difficulty with mocking annotations.
Transition from @MockBean to @MockitoBean
Prior to Spring Boot 3.4.0, developers relied heavily on @MockBean and @SpyBean. Spring introduced a gradual deprecation of these two annotations, promoting instead the new and improved annotation @MockitoBean. This annotation aims to simplify integration testing by reducing complexity and providing clearer mock integrations.
Discrepancy: Local vs Jenkins Environment
A confusing phenomenon occurs when your test code passes beautifully on your local machine but explodes spectacularly when pushed to Jenkins pipelines. Locally, your Spring Boot tests run successfully—your mocks are working as expected, injection is flawless. But Jenkins continuously throws errors—typically around bean injection and dependency initialization.
This unfortunately common scenario happened again after migrating tests to @MockitoBean. What works seamlessly on your machine causes confusion when executed on Jenkins—leading to failures and wasted hours.
Class Structure & Hierarchy Explanation
The structure typically consists of a few layers of abstraction to reuse mocks and testing context:
- DefaultTestConfig.java annotation class to create a default context and configuration shared across tests.
- BaseAPITest.java abstract class responsible for common functionality and base mock setups required for all API tests.
- SomeBaseAPITest.java intermediate-level abstraction, further customized to specific modules or contexts.
- MyTest.java specific implementations dedicated to testing a particular feature or endpoint.
Such hierarchy allows tests to remain clean, readable, and efficient—maintaining a consistent testing context across multiple test cases.
Example Code Snippets and Usage Overview
Below are simplified examples demonstrating the core of the structure:
DefaultTestConfig.java:
@Retention(RetentionPolicy.RUNTIME)
@ExtendWith(SpringExtension.class)
@ContextConfiguration(classes = { MyApp.class })
public @interface DefaultTestConfig {}
BaseAPITest.java:
@DefaultTestConfig
public abstract class BaseAPITest {
@BeforeSuite
public void setup() { /* shared mock setup */ }
}
SomeBaseAPITest.java:
public abstract class SomeBaseAPITest extends BaseAPITest {
@MockitoBean
protected SomeService someService;
}
MyTest.java:
public class MyTest extends SomeBaseAPITest {
@Test
public void testMyStuff() {
when(someService.performAction()).thenReturn("expectedResult");
// Test assertions here
}
}
Error Analysis & Troubleshooting Insights
When running the test suite on Jenkins, developers encounter error messages along these lines:
No qualifying bean of type 'SomeService' available: expected single matching bean but found none
This typically indicates that the context is somehow not picking up or creating the mock bean correctly in Jenkins, despite it functioning locally.
The problematic piece relates directly to @MockitoBean initialization:
@MockitoBean
protected SomeService someService;
Understanding Class Hierarchy Benefits & Context Retention
Why create multiple abstract layers? Mainly context reuse and cleaner maintenance. By abstracting mocked beans and configurations into parent test classes, you reuse test contexts and mocks globally. This significantly reduces redundancy.
The @BeforeSuite method provided by TestNG (official TestNG docs) ensures shared configuration setups once per suite.
Debugging & Attempted Solutions
Several debugging attempts usually seen include:
- Explicitly declaring mocks using AppContext configurations.
- Trying alternative ways of initializing mocks rather than leaning on annotations.
- Adding explicit package-scan configuration in Jenkins jobs.
- Reverting to older annotations temporarily to confirm environmental issues.
Despite attempts, developers often continue hitting the same issue due to environmental specifics within the Jenkins pipeline.
Jenkins Pipeline Structure & Configuration
Your Jenkins pipeline is typically configured like this for running integration tests:
- Checkout Stage
- Maven Build Stage (with test profile)
- Docker Compose or Kubernetes initialization stage (for dependencies)
- Report publication Stage
Example pipeline snippet:
stage ('Tests') {
steps {
sh 'mvn clean verify -P integration-tests'
}
}
Confirm your configuration (profiles activated, environment variables set) matches exactly with local runs to avoid disparities.
Challenges & Real-World Limitations
Main challenges identified during this transition include:
- Issues specifically related to bean initialization timing differences between local and Jenkins environments.
- @MockitoBean annotation handling differences due to stricter context loading in newer Spring Boot versions.
- Nested abstract class initializations might behave differently due to JVM/class-loading intricacies seen on Jenkins due to classloader sensitivity.
Why Does This Occur on Jenkins Only?
The environment difference is mainly due to class loading and annotation scanning discrepancies between local IDE/transient JVM and the persistent Jenkins build environment. Jenkins might impose stricter or different class loader and dependency scopes (such as timing or resource-loading differences), causing the unexpected bean initialization behavior.
What You Expect & Recommended Fixes
Ideally, your Jenkins environment should exactly mirror local setups. However, due to hardware, networking, or classloading intricacies, differences often occur unexpectedly. To resolve this issue, here are recommended actionable tips:
- Explicitly define Mockito initialization via test-specific Spring configurations rather than implicitly relying on annotations alone.
- Use Jenkins pipeline tools or plugins to control environments explicitly.
- Force consistent bean initialization by explicitly loading mock contexts or overriding contexts for problematic classes. See solutions on StackOverflow Spring Boot Tests section.
- If migration issues for annotations persist, consider sticking temporarily with @MockBean until the @MockitoBean approach stabilizes further.
Remember, verify dependencies are identical locally and remotely—this one step often reveals hidden discrepancies.
Facing environment-specific issues like this? Feel free to share your experiences or comment below on how you’ve successfully tackled similar Jenkins and Spring Boot issues—Together, we can find a robust solution.
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