This commit migrates parameterized tests in spring-core using the
"composed @ParameterizedTest" approach. This approach is reused in
follow-up commits for the migration of the remaining modules.
For a concrete example, see AbstractDataBufferAllocatingTests and its
subclasses (e.g., DataBufferTests).
Specifically, AbstractDataBufferAllocatingTests declares a custom
@ParameterizedDataBufferAllocatingTest annotation that is
meta-annotated with @ParameterizedTest and
@MethodSource("org.springframework.core.io.buffer.AbstractDataBufferAllocatingTests#dataBufferFactories()").
Individual methods in concrete subclasses are then annotated with
@ParameterizedDataBufferAllocatingTest instead of @ParameterizedTest or
@Test.
The approach makes the migration from JUnit 4 to JUnit Jupiter rather
straightforward; however, there is one major downside. The arguments
for a @ParameterizedTest test method can only be accessed by the test
method itself. It is not possible to access them in an @BeforeEach
method (see https://github.com/junit-team/junit5/issues/944).
Consequently, we are forced to declare the parameters in each such
method and delegate to a custom "setup" method. Although this is a bit
cumbersome, I feel it is currently the best way to achieve fine grained
parameterized tests within our test suite without implementing a custom
TestTemplateInvocationContextProvider for each specific use case.
Once https://github.com/junit-team/junit5/issues/878 is resolved, we
should consider migrating to parameterized test classes.
See gh-23451
3df85c783f