Merge branch '6.2.x'

This commit is contained in:
Sam Brannen
2025-02-12 15:55:33 +01:00
37 changed files with 1106 additions and 208 deletions

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@@ -1,34 +1,60 @@
[[spring-testing-annotation-beanoverriding-mockitobean]]
= `@MockitoBean` and `@MockitoSpyBean`
`@MockitoBean` and `@MockitoSpyBean` are used on non-static fields in test classes to
override beans in the test's `ApplicationContext` with a Mockito _mock_ or _spy_,
respectively. In the latter case, an early instance of the original bean is captured and
wrapped by the spy.
`@MockitoBean` and `@MockitoSpyBean` can be used in test classes to override a bean in
the test's `ApplicationContext` with a Mockito _mock_ or _spy_, respectively. In the
latter case, an early instance of the original bean is captured and wrapped by the spy.
By default, the annotated field's type is used to search for candidate beans to override.
If multiple candidates match, `@Qualifier` can be provided to narrow the candidate to
override. Alternatively, a candidate whose bean name matches the name of the field will
match.
The annotations can be applied in the following ways.
* On a non-static field in a test class or any of its superclasses.
* On a non-static field in an enclosing class for a `@Nested` test class or in any class
in the type hierarchy or enclosing class hierarchy above the `@Nested` test class.
* At the type level on a test class or any superclass or implemented interface in the
type hierarchy above the test class.
* At the type level on an enclosing class for a `@Nested` test class or on any class or
interface in the type hierarchy or enclosing class hierarchy above the `@Nested` test
class.
When `@MockitoBean` or `@MockitoSpyBean` is declared on a field, the bean to mock or spy
is inferred from the type of the annotated field. If multiple candidates exist in the
`ApplicationContext`, a `@Qualifier` annotation can be declared on the field to help
disambiguate. In the absence of a `@Qualifier` annotation, the name of the annotated
field will be used as a _fallback qualifier_. Alternatively, you can explicitly specify a
bean name to mock or spy by setting the `value` or `name` attribute in the annotation.
When `@MockitoBean` or `@MockitoSpyBean` is declared at the type level, the type of bean
(or beans) to mock or spy must be supplied via the `types` attribute in the annotation
for example, `@MockitoBean(types = {OrderService.class, UserService.class})`. If multiple
candidates exist in the `ApplicationContext`, you can explicitly specify a bean name to
mock or spy by setting the `name` attribute. Note, however, that the `types` attribute
must contain a single type if an explicit bean `name` is configured for example,
`@MockitoBean(name = "ps1", types = PrintingService.class)`.
To support reuse of mock configuration, `@MockitoBean` and `@MockitoSpyBean` may be used
as meta-annotations to create custom _composed annotations_ for example, to define
common mock or spy configuration in a single annotation that can be reused across a test
suite. `@MockitoBean` and `@MockitoSpyBean` can also be used as repeatable annotations at
the type level — for example, to mock or spy several beans by name.
[WARNING]
====
Qualifiers, including the name of the field, are used to determine if a separate
Qualifiers, including the name of a field, are used to determine if a separate
`ApplicationContext` needs to be created. If you are using this feature to mock or spy
the same bean in several test classes, make sure to name the field consistently to avoid
the same bean in several test classes, make sure to name the fields consistently to avoid
creating unnecessary contexts.
====
Each annotation also defines Mockito-specific attributes to fine-tune the mocking behavior.
The `@MockitoBean` annotation uses the `REPLACE_OR_CREATE`
xref:testing/testcontext-framework/bean-overriding.adoc#testcontext-bean-overriding-custom[strategy for test bean overriding].
If no existing bean matches, a new bean is created on the fly. However, you can switch to
the `REPLACE` strategy by setting the `enforceOverride` attribute to `true`. See the
following section for an example.
xref:testing/testcontext-framework/bean-overriding.adoc#testcontext-bean-overriding-strategy[strategy for bean overrides].
If a corresponding bean does not exist, a new bean will be created. However, you can
switch to the `REPLACE` strategy by setting the `enforceOverride` attribute to `true`
for example, `@MockitoBean(enforceOverride = true)`.
The `@MockitoSpyBean` annotation uses the `WRAP`
xref:testing/testcontext-framework/bean-overriding.adoc#testcontext-bean-overriding-custom[strategy],
xref:testing/testcontext-framework/bean-overriding.adoc#testcontext-bean-overriding-strategy[strategy],
and the original instance is wrapped in a Mockito spy. This strategy requires that
exactly one candidate bean exists.
@@ -56,15 +82,8 @@ or `private` depending on the needs or coding practices of the project.
[[spring-testing-annotation-beanoverriding-mockitobean-examples]]
== `@MockitoBean` Examples
When using `@MockitoBean`, a new bean will be created if a corresponding bean does not
exist. However, if you would like for the test to fail when a corresponding bean does not
exist, you can set the `enforceOverride` attribute to `true` for example,
`@MockitoBean(enforceOverride = true)`.
To use a by-name override rather than a by-type override, specify the `name` (or `value`)
attribute of the annotation.
The following example shows how to use the default behavior of the `@MockitoBean` annotation:
The following example shows how to use the default behavior of the `@MockitoBean`
annotation.
[tabs]
======
@@ -81,7 +100,7 @@ Java::
// tests...
}
----
<1> Replace the bean with type `CustomService` with a Mockito `mock`.
<1> Replace the bean with type `CustomService` with a Mockito mock.
======
In the example above, we are creating a mock for `CustomService`. If more than one bean
@@ -90,7 +109,8 @@ will fail, and you will need to provide a qualifier of some sort to identify whi
`CustomService` beans you want to override. If no such bean exists, a bean will be
created with an auto-generated bean name.
The following example uses a by-name lookup, rather than a by-type lookup:
The following example uses a by-name lookup, rather than a by-type lookup. If no bean
named `service` exists, one is created.
[tabs]
======
@@ -108,32 +128,9 @@ Java::
}
----
<1> Replace the bean named `service` with a Mockito `mock`.
<1> Replace the bean named `service` with a Mockito mock.
======
If no bean named `service` exists, one is created.
`@MockitoBean` can also be used at the type level:
- on a test class or any superclass or implemented interface in the type hierarchy above
the test class
- on an enclosing class for a `@Nested` test class or on any class or interface in the
type hierarchy or enclosing class hierarchy above the `@Nested` test class
When `@MockitoBean` is declared at the type level, the type of bean (or beans) to mock
must be supplied via the `types` attribute for example,
`@MockitoBean(types = {OrderService.class, UserService.class})`. If multiple candidates
exist in the application context, you can explicitly specify a bean name to mock by
setting the `name` attribute. Note, however, that the `types` attribute must contain a
single type if an explicit bean `name` is configured for example,
`@MockitoBean(name = "ps1", types = PrintingService.class)`.
To support reuse of mock configuration, `@MockitoBean` may be used as a meta-annotation
to create custom _composed annotations_ — for example, to define common mock
configuration in a single annotation that can be reused across a test suite.
`@MockitoBean` can also be used as a repeatable annotation at the type level — for
example, to mock several beans by name.
The following `@SharedMocks` annotation registers two mocks by-type and one mock by-name.
[tabs]
@@ -191,7 +188,7 @@ APIs.
== `@MockitoSpyBean` Examples
The following example shows how to use the default behavior of the `@MockitoSpyBean`
annotation:
annotation.
[tabs]
======
@@ -208,7 +205,7 @@ Java::
// tests...
}
----
<1> Wrap the bean with type `CustomService` with a Mockito `spy`.
<1> Wrap the bean with type `CustomService` with a Mockito spy.
======
In the example above, we are wrapping the bean with type `CustomService`. If more than
@@ -216,7 +213,7 @@ one bean of that type exists, the bean named `customService` is considered. Othe
the test will fail, and you will need to provide a qualifier of some sort to identify
which of the `CustomService` beans you want to spy.
The following example uses a by-name lookup, rather than a by-type lookup:
The following example uses a by-name lookup, rather than a by-type lookup.
[tabs]
======
@@ -233,5 +230,58 @@ Java::
// tests...
}
----
<1> Wrap the bean named `service` with a Mockito `spy`.
<1> Wrap the bean named `service` with a Mockito spy.
======
The following `@SharedSpies` annotation registers two spies by-type and one spy by-name.
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes"]
----
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
@MockitoSpyBean(types = {OrderService.class, UserService.class}) // <1>
@MockitoSpyBean(name = "ps1", types = PrintingService.class) // <2>
public @interface SharedSpies {
}
----
<1> Register `OrderService` and `UserService` spies by-type.
<2> Register `PrintingService` spy by-name.
======
The following demonstrates how `@SharedSpies` can be used on a test class.
[tabs]
======
Java::
+
[source,java,indent=0,subs="verbatim,quotes"]
----
@SpringJUnitConfig(TestConfig.class)
@SharedSpies // <1>
class BeanOverrideTests {
@Autowired OrderService orderService; // <2>
@Autowired UserService userService; // <2>
@Autowired PrintingService ps1; // <2>
// Inject other components that rely on the spies.
@Test
void testThatDependsOnMocks() {
// ...
}
}
----
<1> Register common spies via the custom `@SharedSpies` annotation.
<2> Optionally inject spies to _stub_ or _verify_ them.
======
TIP: The spies can also be injected into `@Configuration` classes or other test-related
components in the `ApplicationContext` in order to configure them with Mockito's stubbing
APIs.

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@@ -2,8 +2,8 @@
= Bean Overriding in Tests
Bean overriding in tests refers to the ability to override specific beans in the
`ApplicationContext` for a test class, by annotating one or more non-static fields in the
test class.
`ApplicationContext` for a test class, by annotating the test class or one or more
non-static fields in the test class.
NOTE: This feature is intended as a less risky alternative to the practice of registering
a bean via `@Bean` with the `DefaultListableBeanFactory`
@@ -42,15 +42,16 @@ The `spring-test` module registers implementations of the latter two
{spring-framework-code}/spring-test/src/main/resources/META-INF/spring.factories[`META-INF/spring.factories`
properties file].
The bean overriding infrastructure searches in test classes for any non-static field that
is meta-annotated with `@BeanOverride` and instantiates the corresponding
`BeanOverrideProcessor` which is responsible for creating an appropriate
`BeanOverrideHandler`.
The bean overriding infrastructure searches for annotations on test classes as well as
annotations on non-static fields in test classes that are meta-annotated with
`@BeanOverride` and instantiates the corresponding `BeanOverrideProcessor` which is
responsible for creating an appropriate `BeanOverrideHandler`.
The internal `BeanOverrideBeanFactoryPostProcessor` then uses bean override handlers to
alter the test's `ApplicationContext` by creating, replacing, or wrapping beans as
defined by the corresponding `BeanOverrideStrategy`:
[[testcontext-bean-overriding-strategy]]
`REPLACE`::
Replaces the bean. Throws an exception if a corresponding bean does not exist.
`REPLACE_OR_CREATE`::