Inconsistent validation of query parameters when using MockMvc

[mharward]

Affects: spring-test:5.1.6

---

When using MockMvc to perform test requests of a @Validated controller endpoint, validations (javax.validation.constraints) are not applied in certain cases depending on the formatting of the URI.

mockMvc.perform(get("/my-endpoint?param={param}", "value"))... // Works
mockMvc.perform(get(format("/my-endpoint?param=%s", "value")))... // Works 
mockMvc.perform(get("/my-endpoint?param=%s", "value"))... // Works, but not when doing validation
mockMvc.perform(get("/my-endpoint?param={}", "value"))... // Works, but not when doing validation

Just raising this in case it can be made more consistent or if this might help someone else in the future.

[sbrannen]

Can you please provide the code for the mapped controller method that you are testing?

[mharward]

@sbrannen here is a stripped down example of the controller...

@RestController
@Validated
public class MyController {

    @GetMapping("/my-endpoint")
    public AResponse myEndpoint(
            @RequestParam
            @Pattern(regexp = "\\d+", message = "Invalid param, must be number")
            String param)
            {...}
}

[sbrannen]

What happens if you move the @Validated annotation to the method parameter to be validated like the following?

@RestController
public class MyController {

    @GetMapping("/my-endpoint")
    public AResponse myEndpoint(
            @Validated
            @RequestParam
            @Pattern(regexp = "\\d+", message = "Invalid param, must be number")
            String param)
            {...}
}

[mharward]

@sbrannen, in that case the validation does not appear happen in any of the above examples.

[sbrannen]

Thanks for trying that and reporting back.

And... I apologize: that's not supposed to work. @Validated is only supported directly on handler method parameters for model attribute, @RequestBody, and @RequestPart arguments. See #11041.

[sbrannen]

All of the examples you have supplied pass with proper validation for me, as can be seen in the following passing test class.

import javax.validation.ConstraintViolationException;
import javax.validation.constraints.Pattern;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.test.context.junit.jupiter.web.SpringJUnitWebConfig;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.validation.annotation.Validated;
import org.springframework.validation.beanvalidation.MethodValidationPostProcessor;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.util.NestedServletException;

import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
import static org.springframework.test.web.servlet.setup.MockMvcBuilders.webAppContextSetup;

@SpringJUnitWebConfig
class ValidatedControllerTests {

	MockMvc mockMvc;


	@BeforeEach
	void setUp(WebApplicationContext wac) {
		this.mockMvc = webAppContextSetup(wac).build();
	}

	@Test
	void validationIsApplied() throws Exception {
		assertThatExceptionOfType(NestedServletException.class)//
				.isThrownBy(() -> mockMvc.perform(get("/my-endpoint?param={param}", "value")))//
				.withCauseExactlyInstanceOf(ConstraintViolationException.class);

		assertThatExceptionOfType(NestedServletException.class)//
				.isThrownBy(() -> mockMvc.perform(get(String.format("/my-endpoint?param=%s", "value"))))//
				.withCauseExactlyInstanceOf(ConstraintViolationException.class);

		assertThatExceptionOfType(NestedServletException.class)//
				.isThrownBy(() -> mockMvc.perform(get("/my-endpoint?param=%s", "value")))//
				.withCauseExactlyInstanceOf(ConstraintViolationException.class);
		assertThatExceptionOfType(NestedServletException.class)//
				.isThrownBy(() -> mockMvc.perform(get("/my-endpoint?param={}", "value")))//
				.withCauseExactlyInstanceOf(ConstraintViolationException.class);
	}


	@Configuration
	@EnableWebMvc
	static class WebConfig {

		@Bean
		MethodValidationPostProcessor methodValidationPostProcessor() {
			return new MethodValidationPostProcessor();
		}

		@Bean
		MyController myController() {
			return new MyController();
		}
	}

	@RestController
	@Validated
	static class MyController {

		@GetMapping("/my-endpoint")
		String myEndpoint(@RequestParam @Pattern(regexp = "\\d+", message = "Must be a number") String param) {
			return "results";
		}
	}

}

I am therefore closing this issue.

[sbrannen]

Note, however, that %s and empty {} are not supported as placeholders in URL templates. Thus, you cannot use those within the urlTemplate you supply to org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get(String, Object...), since the literal string values "%s" and "{}" are not numbers as required by your controller method.