How to test @Valid

Question

In my entities I have some hibernate annotations for validation, like @NotEmpty, @Pattern.. and others

In my controller, on save action, it has an @Valid parameter.

But if any entity has any required field, and there is no annotation I will have problems.

So I would like to test each entity, to ensure they have the necessary notes.

Something like:

@Test(expect=IllegalArgumentException.class)
public void testAllNull() {
    Person p = new Persson(); // Person name has an @NotEmpty
    validator.validate(p);
}

But how to validate it? Who is called to check @Valid?

Thanks.

Answer 1

Here is a Spring v4.1.x based example of a test validating presence and processing of the @Valid annotation and building of custom JSON response in case of an error.

jUnit

import com.fasterxml.jackson.core.type.TypeReference;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.context.annotation.Bean;
import org.springframework.http.MediaType;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.MvcResult;
import org.springframework.test.web.servlet.setup.MockMvcBuilders;

import javax.inject.Inject;
import java.util.List;

import static org.abtechbit.miscboard.util.JsonUtils.toJson;
import static org.hamcrest.CoreMatchers.is;
import static org.hamcrest.CoreMatchers.notNullValue;
import static org.junit.Assert.assertThat;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = {
        RegistrationValidationTest.MockDependencies.class,
})
public class RegistrationValidationTest {

    @Inject
    MockMvc mvc;

    @Test
    public void validatesRegistration() throws Exception {
        Registration registration = ... //build an invalid Registration object
        MvcResult result = mvc.perform(post(RegistrationController.CONTEXT_REGISTER).
                contentType(MediaType.APPLICATION_JSON).
                content(toJson(registration))).
                andExpect(status().isBadRequest()).
                andExpect(content().contentType(MediaType.APPLICATION_JSON)).
                andReturn();

        assertThat(result.getResolvedException(), is(notNullValue()));
        String content = result.getResponse().getContentAsString();
        assertThat(content, is(notNullValue()));
        List<Message> messages = JsonUtils.fromJson(content, new TypeReference<List<Message>>() {
        });
        assertThat(messages.size(), is(1));
    }

    public static class MockDependencies {

        @Bean
        public MockMvc mvc() {
            return MockMvcBuilders.standaloneSetup(new RegistrationController()).build();
        }
    }
}

Controller

import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.*;

import javax.validation.Valid;
import java.util.List;
import java.util.stream.Collectors;

@Controller
public class RegistrationController
{
    public static final String CONTEXT_REGISTER = "/register";

    @RequestMapping(value = CONTEXT_REGISTER, method = RequestMethod.POST)
    @ResponseBody
    public String register(@RequestBody @Valid Registration registration) {
        //perform registration
    }

    @ExceptionHandler(MethodArgumentNotValidException.class)
    public ResponseEntity<List> handleValidationException(MethodArgumentNotValidException ex) {
        //Build a list of custom Message{String message;} objects
        List<Message> messages = ex.getBindingResult().getAllErrors().
                stream().map(e->new Message(e.getDefaultMessage())).collect(Collectors.toList());
        return ResponseEntity.status(HttpStatus.BAD_REQUEST).contentType(MediaType.APPLICATION_JSON).body(messages);
    }
}