WebTestClient cannot read matrix variable

[Himai Minh]

Hi, I am writing a test case for Dominik Cebula's Spring Professional Tutorial example. I found out that WebTestClient cannot read matrix variables.
Here is the relevant parts of Dominik's code:

@Controller
public class Example03MatrixVariable {
    // curl http://localhost:8080/example03A/employees/id=1
    @GetMapping("/example03A/employees/{id}")
    @ResponseBody
    public String example03A(@MatrixVariable("id") int id) {
         ....
    }
 ...

@Configuration
public class WebConfig implements WebMvcConfigurer {

   ....
    @Override
    public void configurePathMatch(PathMatchConfigurer configurer) {
        UrlPathHelper urlPathHelper = new UrlPathHelper();
        urlPathHelper.setRemoveSemicolonContent(false);
        configurer.setUrlPathHelper(urlPathHelper);
    }
   ...
}

This is my  Junit 5 test case:

@WebFluxTest(controllers=Example03MatrixVariable.class)
 
class Example03MatrixVariableTest {


    @Autowired
    WebTestClient webTestClient;
    @Test
    public void example03A(){
        String expected = String.format("Received request id = [%d]\n", 1);
        webTestClient.get().uri("http://localhost:8080/example03A/employees/id=1")
                     .exchange()
                     .expectBody().consumeWith(response -> assertTrue(new String(response.getResponseBody(),
                                               StandardCharsets.UTF_8).contains(expected)));
    }
}

But the error is:

 GET http://localhost:8080/example03A/employees/id=1
> WebTestClient-Request-Id: [1]

No content

< 400 BAD_REQUEST Bad Request
< Content-Type: [application/json;charset=UTF-8]
< Content-Length: [189]

{"timestamp":"2020-02-18T19:04:55.109+0000","path":"/example03A/employees/id=1","status":400,"error":"Bad Request","message":"Missing matrix variable 'id' for method parameter of type int"}


	at org.springframework.test.web.reactive.server.ExchangeResult.assertWithDiagnostics(ExchangeResult.java:200)
	at org.springframework.test.web.reactive.server.DefaultWebTestClient$DefaultBodyContentSpec.consumeWith(DefaultWebTestClient.java:540)
	at com.spring.professional.exam.tutorial.module05.question10.controller.Example03MatrixVariableTest.example03A(Example03MatrixVariableTest.java:26)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:532)
	at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:115)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$6(TestMethodTestDescriptor.java:171)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:72)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:167)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:114)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:59)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$4(NodeTestTask.java:108)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:72)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:98)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:74)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1540)
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$4(NodeTestTask.java:112)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:72)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:98)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:74)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1540)
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$4(NodeTestTask.java:112)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:72)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:98)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:74)
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32)
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:51)
	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:220)
	at org.junit.platform.launcher.core.DefaultLauncher.lambda$execute$6(DefaultLauncher.java:188)
	at org.junit.platform.launcher.core.DefaultLauncher.withInterceptedStreams(DefaultLauncher.java:202)
	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:181)
	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:128)
	at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:69)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:230)
	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:58)

Does anyone has any suggestion to fix this issue?


On the other hand, if I use MockMvc, it works.

@SpringBootTest
@AutoConfigureMockMvc
class Example03MatrixVariableTest1 {

    @Autowired
    MockMvc mvc;

    @Test
    public void example03A() throws Exception{
        String expected = String.format("Received request id = [%d]\n", 1);
        mvc.perform(get("http://localhost:8080/example03A/employees/id=1")
                   ).andExpect(content().string(expected));
    }
.....

[Himai Minh]

I can answer my own question.
Instead of using WebFluxTest, use SpringBootTest and AutoConfigureWebTestClient.
According to someone from Spring Community, WebFluxTest ignores the WebMvcConfigurer

Reference:
https://stackoverflow.com/questions/60307284/webfluxtest-cannot-read-matrix-variables/60327750#60327750