Spring boot 2.1 bean override vs. Primary

Question

With Spring Boot 2.1 bean overriding is disabled by default, which is a good thing.

However I do have some tests where I replace beans with mocked instances using Mo

Answer 1

Overriding beans means that there may be only one bean with a unique name or id in the context. So you can provide two beans in the following way:

package com.stackoverflow.foo;
@Configuration
public class BaseConfiguration {
   @Bean
   @Lazy
   public BService bService1() {
       return new BService();
   }
}

package com.stackoverflow.bar;
@Configuration
@Import({BaseConfiguration.class})
public class TestConfiguration {
    @Bean
    public BService bService2() {
        return Mockito.mock(BService.class);
    }
}

If you add @Primary then primary bean will be injected by default in:

@Autowired
BService bService;