How to get proper user from SecurityContextHolder Authentication within integration test using rest assured? - spring-boot

Question

I cannot successfully get the right username within integration test using Rest assured. I do not understand why but Authentication from SecurityContextHolder returns "anonymousUser" instead of "myuser". What is wrong with my config?
Response body doesn't match expectation. Expected: is "Authentication
successful for user myuser" Actual: Authentication successful for
user anonymousUser
Controller:
#RestController
#RequestMapping(value = "/api/ping", produces = TEXT_PLAIN_VALUE)
public class PingController {
#GetMapping
public #ResponseBody String ping() {
Authentication authentication = SecurityContextHolder.getContext().getAuthentication();
return "Authentication successful for user " + authentication.getName();
}
}
Security config:
http.authorizeRequests()
.antMatchers("/api/ping").permitAll()
.antMatchers("/api/**").hasRole(ROLE_API)
//...another roles...
.anyRequest().permitAll()
.and()
.httpBasic()
.authenticationEntryPoint(basicRestAuthenticationEntryPoint)
.and()
.headers().frameOptions().disable()
.and().cors()
.and()
.csrf().disable();
Test:
#Test
void test() {
given()
.contentType(TEXT)
.auth().basic("myuser", "password").
when()
.get("/api/ping").
then()
.statusCode(200)
.body(is("Authentication successful for user: myuser"));
}