Return to site

SpringExtension in Spring app testing: ๐Ÿ††๐Ÿ…ท๐Ÿ†ˆ?

ยท spring,java,testing

๐‘‡โ„Ž๐‘’ ๐‘†๐‘๐‘Ÿ๐‘–๐‘›๐‘”๐ธ๐‘ฅ๐‘ก๐‘’๐‘›๐‘ ๐‘–๐‘œ๐‘› ๐‘“๐‘Ž๐‘๐‘–๐‘™๐‘–๐‘ก๐‘Ž๐‘ก๐‘’๐‘  ๐‘กโ„Ž๐‘’ ๐‘ ๐‘š๐‘œ๐‘œ๐‘กโ„Ž ๐‘–๐‘›๐‘ก๐‘’๐‘”๐‘Ÿ๐‘Ž๐‘ก๐‘–๐‘œ๐‘› ๐‘œ๐‘“ ๐ฝ๐‘ˆ๐‘›๐‘–๐‘ก ๐ฝ๐‘ข๐‘๐‘–๐‘ก๐‘’๐‘Ÿ ๐‘ก๐‘’๐‘ ๐‘ก๐‘  ๐‘ค๐‘–๐‘กโ„Ž ๐‘†๐‘๐‘Ÿ๐‘–๐‘›๐‘”'๐‘  ๐‘‡๐‘’๐‘ ๐‘ก๐ถ๐‘œ๐‘›๐‘ก๐‘’๐‘ฅ๐‘ก ๐‘“๐‘Ÿ๐‘Ž๐‘š๐‘’๐‘ค๐‘œ๐‘Ÿ๐‘˜.

๐ผ๐‘› ๐‘š๐‘œ๐‘ ๐‘ก ๐‘๐‘Ž๐‘ ๐‘’๐‘ , ๐‘กโ„Ž๐‘’๐‘Ÿ๐‘’ ๐‘–๐‘  ๐‘›๐‘œ ๐‘›๐‘’๐‘’๐‘‘ ๐‘ก๐‘œ ๐‘š๐‘Ž๐‘›๐‘ข๐‘Ž๐‘™๐‘™๐‘ฆ ๐‘Ÿ๐‘’๐‘”๐‘–๐‘ ๐‘ก๐‘’๐‘Ÿ ๐‘กโ„Ž๐‘’ ๐‘†๐‘๐‘Ÿ๐‘–๐‘›๐‘”๐ธ๐‘ฅ๐‘ก๐‘’๐‘›๐‘ ๐‘–๐‘œ๐‘› ๐‘ ๐‘–๐‘›๐‘๐‘’ ๐‘Ž๐‘™๐‘™ ๐‘†๐‘๐‘Ÿ๐‘–๐‘›๐‘” ๐ต๐‘œ๐‘œ๐‘ก ๐‘ก๐‘’๐‘ ๐‘ก ๐‘ ๐‘™๐‘–๐‘๐‘’ ๐‘Ž๐‘›๐‘›๐‘œ๐‘ก๐‘Ž๐‘ก๐‘–๐‘œ๐‘›๐‘  ๐‘Ž๐‘ข๐‘ก๐‘œ๐‘š๐‘Ž๐‘ก๐‘–๐‘๐‘Ž๐‘™๐‘™๐‘ฆ โ„Ž๐‘Ž๐‘›๐‘‘๐‘™๐‘’ ๐‘กโ„Ž๐‘–๐‘  ๐‘๐‘Ÿ๐‘œ๐‘๐‘’๐‘ ๐‘ .



๐Ÿ…ฐ๏ธ What is the purpose of a JUnit Jupiter Extension?

The JUnit Jupiter extension model is a unified concept that enhances testing ๐Ÿงช functionality and allows for programmatic interception of test lifecycles.

It is a replacement ๐Ÿ”„๏ธ for JUnit 4's Runner and Rule API.

Typically, extensions are implemented to address cross-cutting concerns that apply to multiple tests.

Numerous frameworks and testing libraries provide their own custom JUnit Jupiter extensions, such as

* ๐Ÿธ MockitoExtension for streamlined mock setup,

* ๐Ÿณ TestcontainersExtension (used with @Testcontainers) for managing Docker containers, and

* ๐Ÿƒ SpringExtension for seamless integration with Spring.



๐Ÿ…ฑ๏ธ What is the purpose of the SpringExtension?

The SpringExtension serves several cross-cutting functionalities, as evidenced by its implementation in the source code.

It implements various interfaces๐Ÿคน , including BeforeAllCallback, AfterAllCallback, TestInstancePostProcessor, BeforeEachCallback, AfterEachCallback, BeforeTestExecutionCallback, AfterTestExecutionCallback, and ParameterResolver.

Its main responsibilities are as follows:

1. Managing the lifecycle ๐Ÿ’— of the Spring TestContext:

The SpringExtension ensures proper initialization, setup, and teardown of the Spring TestContext for test execution.

2. Supporting dependency injection ๐Ÿ’‰ for parameters:

It facilitates the injection of dependencies into test methods or constructors by resolving the required parameters.

3. Performing cleanup and housekeeping ๐Ÿงน tasks after the test:

The SpringExtension handles necessary cleanup ๐Ÿงผ operations, ensuring that resources are properly released and any necessary cleanup tasks are performed.

The SpringExtension acts as a bridge ๐ŸŒ‰ between JUnit Jupiter and the Spring Test framework.

In most cases, it delegates its responsibilities to the TestContextManager, which takes care of managing a single 1๏ธโƒฃ TestContext.



โบ๏ธ When is it necessary to register the SpringExtension?

In most scenarios, explicit registration of the SpringExtension is not โŒ required as it is already activated ๐Ÿ‘ by default.

This activation occurs whenever we utilize a Spring Boot test annotation such as @WebMvcTest, @DataJpaTest, @JdbcTest, @DataMongoTest, @JsonTest, @RestClientTest, or @SpringBootTest.

However, there are certain limited situations where manual registration of the SpringExtension becomes necessary.

One example is when we create a custom test slice annotation, in which case we would need to explicitly register the SpringExtension to ensure its functionality is applied.



๐‘‡โ„Ž๐‘’ ๐‘†๐‘๐‘Ÿ๐‘–๐‘›๐‘”๐ธ๐‘ฅ๐‘ก๐‘’๐‘›๐‘ ๐‘–๐‘œ๐‘› ๐‘–๐‘š๐‘๐‘™๐‘’๐‘š๐‘’๐‘›๐‘ก๐‘  ๐‘ฃ๐‘Ž๐‘Ÿ๐‘–๐‘œ๐‘ข๐‘  ๐‘๐‘Ž๐‘™๐‘™๐‘๐‘Ž๐‘๐‘˜ ๐‘š๐‘’๐‘กโ„Ž๐‘œ๐‘‘๐‘  ๐‘œ๐‘“ ๐‘กโ„Ž๐‘’ ๐ฝ๐‘ˆ๐‘›๐‘–๐‘ก ๐ฝ๐‘ข๐‘๐‘–๐‘ก๐‘’๐‘Ÿ ๐‘’๐‘ฅ๐‘ก๐‘’๐‘›๐‘ ๐‘–๐‘œ๐‘› ๐‘š๐‘œ๐‘‘๐‘’๐‘™, ๐‘’๐‘›๐‘Ž๐‘๐‘™๐‘–๐‘›๐‘” ๐‘ ๐‘š๐‘œ๐‘œ๐‘กโ„Ž ๐‘–๐‘›๐‘ก๐‘’๐‘”๐‘Ÿ๐‘Ž๐‘ก๐‘–๐‘œ๐‘› ๐‘๐‘’๐‘ก๐‘ค๐‘’๐‘’๐‘› ๐ฝ๐‘ˆ๐‘›๐‘–๐‘ก ๐‘Ž๐‘›๐‘‘ ๐‘†๐‘๐‘Ÿ๐‘–๐‘›๐‘”.

๐ผ๐‘› ๐‘กโ„Ž๐‘’ ๐‘๐‘œ๐‘›๐‘ก๐‘’๐‘ฅ๐‘ก ๐‘œ๐‘“ ๐‘ก๐‘’๐‘ ๐‘ก๐‘–๐‘›๐‘” ๐‘†๐‘๐‘Ÿ๐‘–๐‘›๐‘” ๐ต๐‘œ๐‘œ๐‘ก ๐‘Ž๐‘๐‘๐‘™๐‘–๐‘๐‘Ž๐‘ก๐‘–๐‘œ๐‘›๐‘ , ๐‘กโ„Ž๐‘’๐‘Ÿ๐‘’ ๐‘–๐‘  ๐‘ข๐‘ ๐‘ข๐‘Ž๐‘™๐‘™๐‘ฆ ๐‘›๐‘œ ๐‘›๐‘’๐‘’๐‘‘ ๐‘ก๐‘œ ๐‘š๐‘Ž๐‘›๐‘ข๐‘Ž๐‘™๐‘™๐‘ฆ ๐‘Ÿ๐‘’๐‘”๐‘–๐‘ ๐‘ก๐‘’๐‘Ÿ ๐‘กโ„Ž๐‘–๐‘  ๐‘’๐‘ฅ๐‘ก๐‘’๐‘›๐‘ ๐‘–๐‘œ๐‘› ๐‘๐‘’๐‘๐‘Ž๐‘ข๐‘ ๐‘’ ๐‘–๐‘ก ๐‘–๐‘  ๐‘Ž๐‘ข๐‘ก๐‘œ๐‘š๐‘Ž๐‘ก๐‘–๐‘๐‘Ž๐‘™๐‘™๐‘ฆ โ„Ž๐‘Ž๐‘›๐‘‘๐‘™๐‘’๐‘‘ ๐‘๐‘ฆ ๐‘กโ„Ž๐‘’ ๐‘ ๐‘™๐‘–๐‘๐‘’๐‘‘ ๐‘๐‘œ๐‘›๐‘ก๐‘’๐‘ฅ๐‘ก ๐‘Ž๐‘›๐‘›๐‘œ๐‘ก๐‘Ž๐‘ก๐‘–๐‘œ๐‘›๐‘  ๐‘ ๐‘ข๐‘โ„Ž ๐‘Ž๐‘  @๐‘Š๐‘’๐‘๐‘€๐‘ฃ๐‘๐‘‡๐‘’๐‘ ๐‘ก.

๐ผ๐‘“ ๐‘ฆ๐‘œ๐‘ข ๐‘ค๐‘–๐‘ โ„Ž ๐‘ก๐‘œ ๐‘’๐‘ฅ๐‘๐‘™๐‘œ๐‘Ÿ๐‘’ ๐‘กโ„Ž๐‘–๐‘  ๐‘ก๐‘œ๐‘๐‘–๐‘ ๐‘“๐‘ข๐‘Ÿ๐‘กโ„Ž๐‘’๐‘Ÿ, ๐‘Ÿ๐‘’๐‘“๐‘’๐‘Ÿ๐‘Ÿ๐‘–๐‘›๐‘” ๐‘ก๐‘œ ๐‘กโ„Ž๐‘’ ๐‘œ๐‘“๐‘“๐‘–๐‘๐‘–๐‘Ž๐‘™ ๐‘‘๐‘œ๐‘๐‘ข๐‘š๐‘’๐‘›๐‘ก๐‘Ž๐‘ก๐‘–๐‘œ๐‘› ๐‘–๐‘  โ„Ž๐‘–๐‘”โ„Ž๐‘™๐‘ฆ ๐‘Ÿ๐‘’๐‘๐‘œ๐‘š๐‘š๐‘’๐‘›๐‘‘๐‘’๐‘‘ ๐‘Ž๐‘  ๐‘–๐‘ก ๐‘๐‘Ÿ๐‘œ๐‘ฃ๐‘–๐‘‘๐‘’๐‘  ๐‘๐‘œ๐‘š๐‘๐‘Ÿ๐‘’โ„Ž๐‘’๐‘›๐‘ ๐‘–๐‘ฃ๐‘’ ๐‘–๐‘›๐‘“๐‘œ๐‘Ÿ๐‘š๐‘Ž๐‘ก๐‘–๐‘œ๐‘› ๐‘œ๐‘› ๐‘กโ„Ž๐‘’ ๐‘ ๐‘ข๐‘๐‘—๐‘’๐‘๐‘ก.