spring-security: WebMvcTest / MockMvc bug with mocked Authentication ?

Summary

Injected Authentication as @Controller method parameter is null in a @WebMvcTest when using a (Mockito) mocked authentication.

I tried with both an annotation and a request post processor.

Note that I have not the same problem in @WebFluxTest, using the same annotation or a WebTestClient Configurer with implementation very similar to above mentioned post-processor.

Actual / Expected Behavior

The mocked authentication from the TestSecurityContext is not injected when it should

Version

Versions pulled by boot 2.2.6.Release (same issue at least with 2.2.4 and 2.2.5)

Sample

You can clone https://github.com/ch4mpy/spring-addons which contains

• the code for the @WithMockAuthentication annotation and its security context factory
• the code for the MockAuthenticationRequestPostProcessor MockMvc request post-processor
• sample of failing @WebMvcTest using both @WithMockAuthentication and MockAuthenticationRequestPostProcessor
• sample of passing @WebFluxTest using @WithMockAuthentication
• sample of passing @WebFluxTest using MockAuthenticationWebTestClientConfigurer

What I’d like to use:

	@Test
	@WithMockAuthentication(
			authType = OidcIdAuthenticationToken.class,
			name = "Ch4mpy",
			authorities = "ROLE_AUTHORIZED_PERSONNEL")
	public void greetCh4mpyWithAnnotation() throws Exception {
		api.get("/greet")
				.andExpect(content().string("Hello Ch4mpy! You are granted with [ROLE_AUTHORIZED_PERSONNEL]."));
	}

	@Test
	public void greetCh4mpyWithRequestPostProcessor() throws Exception {
		api.with(
				mockAuthentication(OidcIdAuthenticationToken.class).name("Ch4mpy")
						.authorities("ROLE_AUTHORIZED_PERSONNEL"))
				.get("/greet")
				.andExpect(content().string("Hello Ch4mpy! You are granted with [ROLE_AUTHORIZED_PERSONNEL]."));
	}

Whith a controller like:

@RestController
public class GreetingController {
	private final MessageService<OidcIdAuthenticationToken> messageService;

	@Autowired
	public GreetingController(MessageService<OidcIdAuthenticationToken> messageService) {
		this.messageService = messageService;
	}

	@GetMapping("/greet")
	public String greet(OidcIdAuthenticationToken auth) {
		return messageService.greet(auth);
	}
}