Closes gh-23834

Centralized maxInMemorySize exposed via CodecConfigurer along with
ability to plug in an instance of MultipartHttpMessageWrite.

Closes gh-23884

- Add maxInMemorySize property to Decoder and HttpMessageReader
  implementations that aggregate input to trigger
  DataBufferLimitException when reached.

- For codecs that call DataBufferUtils#join, there is now an overloaded
  variant with a maxInMemorySize extra argument. Internally, a custom
  LimitedDataBufferList is used to count and enforce the limit.

- Jackson2Tokenizer and XmlEventDecoder support those limits per
  streamed JSON object.

See gh-23884

Update `AnnotationTypeMappings` so that a custom `RepeatableContainers`
instances can be used. Prior to this commit, only standard repeatables
were used when reading the annotations. This works in most situations,
but causes regressions for some `AnnotationUtils` methods.

Fixed gh-23856

Update `TypeMappedAnnotation` mirror resolution logic so that mapped
annotation values are also considered. Prior to this commit, mirrors
in more complex meta-annotation scenarios would not resolve correctly.

Specifically, given the following:

 @interface TestAliased {

 	@AliasFor(attribute = "qualifier")
 	String value() default "";

 	@AliasFor(attribute = "value")
 	String qualifier() default "";
 }

 @TestAliased
 @interface TestMetaAliased {

 	@AliasFor(annotation = Aliased.class, attribute = "value")
 	String value() default "";
 }

 @TestMetaAliased("test")
 @interface TestComposed {
 }

A merged `@TestAliased` annotation obtained from a `@TestComposed`
root annotation would return a `value` and `qualifier` of "".

This was because the "value" and "qualifier" mirrors needed to be
resolved against the `@TestMetaAliased` meta-annotation. They cannot be
resolved against the declared `@TestComposed` annotation because it
does not have any attributes. Our previous tests only covered a single
depth scenario where `@TestMetaAliased` was used directly on the
annotated element.

Closes gh-23767
Co-authored-by: NSam Brannen <sbrannen@pivotal.io>

See gh-23539
Co-authored-by: NSam Brannen <sbrannen@pivotal.io>

Ensure that results returned from keySet, entrySet & values are tracked
to remove case insensitive keys from the source map.

Closes gh-22821

Prior to this commit, a lot of work had been done to prevent improper
use of testing Framework APIs throughout the codebase; however, there
were still some loopholes.

This commit addresses these loopholes by introducing additional
Checkstyle rules (and modifying existing rules) to prevent improper use
of testing framework APIs in production code as well as in test code.

- Checkstyle rules for banned imports have been refactored into
  multiple rules specific to JUnit 3, JUnit 4, JUnit Jupiter, and
  TestNG.
- Accidental usage of org.junit.Assume has been switched to
  org.junit.jupiter.api.Assumptions.
- All test classes now reside under org.springframework packages.
- All test classes (including abstract test classes) now conform to the
  `*Tests` naming convention.
  - As an added bonus, tests in the renamed
    ScenariosForSpringSecurityExpressionTests are now included in the
    build.
- Dead JUnit 4 parameterized code has been removed from
  DefaultServerWebExchangeCheckNotModifiedTests.

Closes gh-22962

See gh-23605

Prior to this commit, Spring failed to determine that an XML config file
was DTD-based if the DTD declaration was followed by a comment.

This commit fixes this by modifying the consumeCommentTokens(String)
algorithm in XmlValidationModeDetector so that both leading and trailing
comments are properly consumed without losing any XML content.

Closes gh-23605

This commit revives some previously disabled tests and converts
some usage of @Disabled to @EnabledForTestGroups(...).

See gh-23539

The org.reactivestreams has 13 instead of 4 classes in 1.0.3 with the
addition of Java 9 Flow adapters. This commit switches to using a
different package reactor.util.annotation, also with a small number of
classes, for this test.

See gh-23572

Prior to this commit, ClassUtils.isPrimitiveOrWrapper() and
ClassUtils.isPrimitiveWrapper() did not return true for Void.class.
However, ClassUtils.isPrimitiveOrWrapper() did return true for
void.class. This lacking symmetry is inconsistent and can lead to bugs
in reflective code.

See: https://github.com/spring-projects/spring-data-r2dbc/issues/159

This commit addresses this by adding an entry for Void.class -> void.class
in the internal primitiveWrapperTypeMap in ClassUtils.

Closes gh-23572

Closes gh-23475

This commit prepends "[{index}] " to all custom display names
configured via @ParameterizedTest.

This provides better diagnostics between the "technical names" reported
on the CI server vs. the "display names" reported within a developer's
IDE.

See gh-23451

This commit introduces a test that verifies that
PathMatchingResourcePatternResolver can find files in the filesystem
that contain hashtags (#) in their names.

See gh-23532

This is an attempt to solve a build issue on Microsoft Windows.

See gh-23507

Due to a bug (or "unintentional feature") in JUnit 4, overridden test
methods not annotated with @test are still executed as test methods;
however, JUnit Jupiter does not support that. Thus, prior to this
commit, some overridden test methods in spring-core were no longer
executed after the migration from JUnit 4 to JUnit Jupiter.

This commit addresses this issue for such known use cases, but there
are likely other such use cases within Spring's test suite.

See gh-23451

See gh-23451

Closes gh-23476

This commit removes the JUnit 4 dependency from all modules except
spring-test which provides explicit JUnit 4 support.

This commit also includes the following.

- migration from JUnit 4 assertions to JUnit Jupiter assertions in all
  Kotlin tests
- migration from JUnit 4 assumptions in Spring's TestGroup support to
  JUnit Jupiter assumptions, based on org.opentest4j.TestAbortedException
- introduction of a new TestGroups utility class than can be used from
  existing JUnit 4 tests in the spring-test module in order to perform
  assumptions using JUnit 4's Assume class

See gh-23451

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

This first commit for this issue:

- allows JUnit Jupiter to be used for all tests
- adds a dependency on mockito-junit-jupiter
- migrates tests in spring-core to JUnit Jupiter, except parameterized
  tests

The following script was developed in order to semi-automate the
migration process.

https://github.com/sbrannen/junit-converters/blob/master/junit4ToJUnitJupiter.zsh

See gh-23451

See gh-23451

Prior to this commit, StopWatch used System.currentTimeMillis() to
track and report running time in milliseconds.

This commit updates the internals of StopWatch to use System.nanoTime()
instead of System.currentTimeMillis(). Consequently, running time is
now tracked and reported in nanoseconds; however, users still have the
option to retrieve running time in milliseconds or seconds.

Closes gh-23235

Since arbitrary levels of proxies do not occur, this commit replaces
the `while` loop in SerializableTypeWrapper.unwrap() with a simple
`if` statement.

Closes gh-23415

Prior to this commit, AnnotationAttributes#assertNotException checked if
the attribute value was an instance of Exception. Although this was
typically sufficient, the scope was not always broad enough -- for
example, if AnnotationReadingVisitorUtils#convertClassValues stored a
Throwable in the map (such as a LinkageError).

This commit fixes this by checking for an instance of Throwable in
AnnotationAttributes#assertNotException.

Closes gh-23424

Deprecate all mutation methods in `MethodParameter` in favor of factory
methods that return a new instance. Existing code that previously relied
on mutation has been updated to use the replacement methods.

Closes gh-23385