MockMvcWebTestClient cannot handle null in ResponseBody #33977
Description
When using MockMvcWebTestClient.bindToController to a controller with an annotated endpoint which returns null. Then the WebTestClient crashes when calling expectBody with the following message:
Content type 'application/octet-stream' not supported for bodyType=java.time.LocalDate
org.springframework.web.reactive.function.UnsupportedMediaTypeException: Content type 'application/octet-stream' not supported for bodyType=java.time.LocalDate
at org.springframework.web.reactive.function.BodyExtractors.readWithMessageReaders(BodyExtractors.java:205)
Suppressed: The stacktrace has been enhanced by Reactor, refer to additional information below:
Error has been observed at the following site(s):
*__checkpoint ⇢ Body from GET /date [DefaultClientResponse]
Expected behaviour is for it not to crash and for getResponseBody to return null.
Controller class:
package com.example.demo;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import java.time.LocalDate;
@RestController
public class DemoController {
@GetMapping(value = "date", produces = MediaType.APPLICATION_JSON_VALUE)
public LocalDate date() {
return null;
}
}Test class:
package com.example.demo;
import org.assertj.core.api.Assertions;
import org.junit.jupiter.api.Test;
import org.springframework.http.MediaType;
import org.springframework.test.web.servlet.client.MockMvcWebTestClient;
import java.time.LocalDate;
class DemoControllerTest {
@Test
void mvcTest() {
var client = MockMvcWebTestClient.bindToController(new DemoController())
.configureClient()
.build();
var res = client.get()
.uri("/date")
.accept(MediaType.APPLICATION_JSON)
.exchange()
.expectBody(LocalDate.class)
.returnResult()
.getResponseBody();
Assertions.assertThat(res).isNull();
}
}Repository with reproducible example: https://github.com/gustavhagland/mock-mvc-issue