Prior to this commit, if a developer accidentally copied and pasted the
same @ContextConfiguration or @TestPropertySource declaration from a
test class to one of its subclasses or nested test classes, the Spring
TestContext Framework (TCF) would merge the inherited configuration
with the local configuration, resulting in different sets of
configuration metadata which in turn resulted in a different
ApplicationContext instance being loaded for the test classes. This
behavior led to unnecessary creation of identical application contexts
in the context cache for the TCF stored under different keys.
This commit ignores duplicate configuration metadata when generating
the ApplicationContext cache key (i.e., MergedContextConfiguration) in
the TCF. This is performed for the following annotations.
- @ContextConfiguration
- @ActiveProfiles (support already existed prior to this commit)
- @TestPropertySource
Specifically, if @ContextConfiguration or @TestPropertySource is
declared on a test class and its subclass or nested test class with the
exact same attributes, only one instance of the annotation will be used
to generate the cache key for the resulting ApplicationContext. The
exception to this rule is an "empty" annotation declaration. An empty
@ContextConfiguration or @TestPropertySource declaration signals that
Spring (or a third-party SmartContextLoader) should detect default
configuration specific to the annotated class. Thus, multiple empty
@ContextConfiguration or @TestPropertySource declarations within a test
class hierarchy are not considered to be duplicate configuration and
are therefore not ignored.
Since @TestPropertySource is a @Repeatable annotation, the same
duplicate configuration detection logic is applied for multiple
@TestPropertySource declarations on a single test class or test
interface.
In addition, this commit reinstates validation of the rules for
repeated @TestPropertySource annotations that was removed when support
for @NestedTestConfiguration was introduced.
Closes gh-25800
ada255d584