我想模拟一个Bean（使用mockito），它是这样定义的

@Bean("idGenerator")
public Supplier<UUID> idGenerator() {
  return () -> UUID.randomUUID();
}

在一个SpringBootTest-类中，我使用@MockBean时遇到一个错误，指示该Bean不能被模拟（由于JVM中的一些限制？-抱歉，我现在手头没有堆栈跟踪）。
我提出了一个解决方法，不使用Mocks，而是在@TestConfiguration中使用一个附加字段，以便可以从外部指定供应商的返回值。
由于我并不喜欢这种变通方法（我的同事也不会喜欢），我希望有一个被证明的模式，或者意识到我这样做是错误的。

编辑

下面是我得到的堆栈跟踪。正如Markus所指出的--标准单元测试可以工作--这似乎是cucumber-java的一个缺点：

Before All/After All failed
io.cucumber.core.exception.CompositeCucumberException: There were 15 exceptions. The details are in the stacktrace below.
    at io.cucumber.core.runtime.RethrowingThrowableCollector.getThrowable(RethrowingThrowableCollector.java:57)
    at io.cucumber.core.runtime.CucumberExecutionContext.getThrowable(CucumberExecutionContext.java:102)
    at io.cucumber.core.runtime.CucumberExecutionContext.finishTestRun(CucumberExecutionContext.java:97)
    at io.cucumber.core.runtime.Runtime.execute(Runtime.java:96)
    at io.cucumber.core.runtime.Runtime.run(Runtime.java:87)
    at io.cucumber.core.cli.Main.run(Main.java:87)
    at io.cucumber.core.cli.Main.main(Main.java:30)
    Suppressed: java.lang.IllegalStateException: Failed to load ApplicationContext
        at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:98)
        at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:124)
        at io.cucumber.spring.TestContextAdaptor.<init>(TestContextAdaptor.java:32)
        at io.cucumber.spring.SpringFactory.start(SpringFactory.java:120)
        at io.cucumber.core.runner.Runner.buildBackendWorlds(Runner.java:134)
[...]
    Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name [...]: Unsatisfied dependency expressed through constructor parameter 5: Initialization of bean failed; 
    nested exception is org.mockito.exceptions.base.MockitoException: 
Cannot mock/spy class BackendApplicationConfiguration$$Lambda$1713/0x00000008018fd980
Mockito cannot mock/spy because :
 - VM does not support modification of given type
        at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:800)
        at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:229)