SPR-12429 introduced various `BEFORE_*` modes in `@DirtiesContext`. To
support these new modes, `DirtiesContextTestExecutionListener` (DCTEL)
was updated to support both `BEFORE_*` and `AFTER_*` modes. However,
there is a problem with having DCTEL support `BEFORE_*` modes since it
is typically configured to execute after the
`DependencyInjectionTestExecutionListener` (DITEL), and this leads to
several undesired side effects:
- The test's `ApplicationContext` is closed by DCTEL *after*
dependencies have been injected into the test instance.
- Injected dependencies may therefore attempt to interact with an
`ApplicationContext` that is no longer _active_.
- If a test has its `ApplicationContext` injected as a dependency,
interaction with the context will likely fail since the context has
been closed.
- Any `TestExecutionListeners` registered after DCTEL will get a _new_
`ApplicationContext` if they invoke `getApplicationContext()` on the
`TestContext`.
This commit fixes these issues by introducing a new
`DirtiesContextBeforeModesTestExecutionListener` (DCBMTEL) that is
registered by default before DITEL. The previous support for `BEFORE_*`
modes has been moved from DCTEL to DCBMTEL. In addition, an
`AbstractDirtiesContextTestExecutionListener` has been extracted from
DCTEL in order to avoid code duplication.
Issue: SPR-13180
Prior to this commit, there was no declarative mechanism for a custom
TestExecutionListener to be registered as a default
TestExecutionListener.
This commit introduces support for discovering default
TestExecutionListener implementations via the SpringFactoriesLoader
mechanism. Specifically, the spring-test module declares all core
default TestExecutionListeners under the
org.springframework.test.context.TestExecutionListener key in its
META-INF/spring.factories properties file, and third-party frameworks
and developers can contribute to the list of default
TestExecutionListeners in the same manner.
- AbstractTestContextBootstrapper uses the SpringFactoriesLoader to
look up the class names of all registered default
TestExecutionListeners and sorts the instantiated listeners using
AnnotationAwareOrderComparator.
- DefaultTestContextBootstrapper and WebTestContextBootstrapper now
rely on the SpringFactoriesLoader mechanism for finding default
TestExecutionListeners instead of hard coding fully qualified class
names.
- To ensure that default TestExecutionListeners are registered in the
correct order, each can implement Ordered or declare @Order.
- AbstractTestExecutionListener and all default TestExecutionListeners
provided by Spring now implement Ordered with appropriate values.
- Introduced "copy constructors" in MergedContextConfiguration and
WebMergedContextConfiguration
- SpringFactoriesLoader now uses AnnotationAwareOrderComparator
instead of OrderComparator.
Issue: SPR-11466
