How to make Junit test in spring boot

Fadi Published at Java

Fadi

I want to test the behaviour of my rest controller methods, using Mockito.test.

I have the following controller class

    @RestController
    @RequestMapping("/project/image")
    public class ImageController {
        @Autowired
        ImgService imageService;    
    
    
        @GetMapping("/getImage/{id}")
    public ResponseEntity<Image> getImageById(@PathVariable Integer id) {
        Optional<Image> img = imageService.getImageById(id);
        return new ResponseEntity<Image>(HttpStatus.OK);    
}   ....

and I am trying to do some basic unit test on the getImageById method and it does not pass the test:


@ExtendWith(SpringExtension.class)
@SpringBootTest
@AutoConfigureMockMvc
public class ImageControllerTest {
    @MockBean
    private ImgService service;
    @Autowired
    private MockMvc mockMvc;

    @Test
    @DisplayName("GET /Image/1 - Found")
    void testGetImageIdFound() throws Exception {
        Image mockImage = new Image(1, "mockPath", "Normal");
        doReturn(Optional.of(mockImage)).when(service).getImageById(1);        mockMvc.perform(get("/getImage/{id}",1).accept(MediaType.APPLICATION_JSON_UTF8))
                .andExpect(jsonPath("$.id", is(1)))
    }

the error I am getting is "content type is not set"

This is the full trace:

java.lang.AssertionError: Content type not set
    at org.springframework.test.util.AssertionErrors.fail(AssertionErrors.java:37)
    at org.springframework.test.util.AssertionErrors.assertTrue(AssertionErrors.java:70)
    at org.springframework.test.util.AssertionErrors.assertNotNull(AssertionErrors.java:106)
    at org.springframework.test.web.servlet.result.ContentResultMatchers.lambda$contentType$0(ContentResultMatchers.java:83)
    at org.springframework.test.web.servlet.MockMvc$1.andExpect(MockMvc.java:196)
    at com.bachelor.ImageControllerTest.testGetImageIdFound(ImageControllerTest.java:61)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.platform.commons.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:686)
    at org.junit.jupiter.engine.execution.MethodInvocation.proceed(MethodInvocation.java:60)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain$ValidatingInvocation.proceed(InvocationInterceptorChain.java:131)
    at org.junit.jupiter.engine.extension.TimeoutExtension.intercept(TimeoutExtension.java:149)
    at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestableMethod(TimeoutExtension.java:140)
    at org.junit.jupiter.engine.extension.TimeoutExtension.interceptTestMethod(TimeoutExtension.java:84)
    at org.junit.jupiter.engine.execution.ExecutableInvoker$ReflectiveInterceptorCall.lambda$ofVoidMethod$0(ExecutableInvoker.java:115)
    at org.junit.jupiter.engine.execution.ExecutableInvoker.lambda$invoke$0(ExecutableInvoker.java:105)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain$InterceptedInvocation.proceed(InvocationInterceptorChain.java:106)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain.proceed(InvocationInterceptorChain.java:64)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain.chainAndInvoke(InvocationInterceptorChain.java:45)
    at org.junit.jupiter.engine.execution.InvocationInterceptorChain.invoke(InvocationInterceptorChain.java:37)
    at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:104)
    at org.junit.jupiter.engine.execution.ExecutableInvoker.invoke(ExecutableInvoker.java:98)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$invokeTestMethod$6(TestMethodTestDescriptor.java:212)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.invokeTestMethod(TestMethodTestDescriptor.java:208)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:137)
    at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.execute(TestMethodTestDescriptor.java:71)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:135)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
    at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
    at java.util.ArrayList.forEach(ArrayList.java:1257)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
    at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
    at java.util.ArrayList.forEach(ArrayList.java:1257)
    at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:139)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:125)
    at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:135)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:123)
    at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:122)
    at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:80)
    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:170)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:154)
    at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:90)
    at org.eclipse.jdt.internal.junit5.runner.JUnit5TestReference.run(JUnit5TestReference.java:89)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:41)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:541)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:763)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:463)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:209)

What am I missing?

gtiwari333

As I mentioned in my comments, I fixed the following problems and now your test passes:

mockMvc.perform(get("/getImage/ doesn't match the full URL to the getImageById
You are not returning img object from the method.
make sure Image class has getters so that JSON will be properly serialized

Working code:

package sotestapp;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Service;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.Optional;

@SpringBootApplication
public class TestApp {
    public static void main(String[] args) {
        SpringApplication.run(TestApp.class, args);
    }
}

@RestController
@RequestMapping("/project/image")
class ImageController {
    @Autowired
    ImgService imageService;

    @GetMapping("/getImage/{id}")
    public ResponseEntity<Image> getImageById(@PathVariable Integer id) {
        Optional<Image> img = imageService.getImageById(id);
        return ResponseEntity.of(img);
    }
}

@Service
class ImgService {
    public Optional<Image> getImageById(Integer id) {
        return Optional.of(new Image(1, "test", "test"));
    }
}

class Image {
    int id;
    String path;
    String normal;

    public Image(int id, String path, String normal) {
        this.id = id;
        this.path = path;
        this.normal = normal;
    }

    public int getId() {
        return id;
    }

    public String getPath() {
        return path;
    }

    public String getNormal() {
        return normal;
    }
}

Test:

package sotestapp;

import org.hamcrest.Matchers;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.boot.test.mock.mockito.MockBean;
import org.springframework.http.MediaType;
import org.springframework.test.web.servlet.MockMvc;

import java.util.Optional;

import static org.mockito.Mockito.doReturn;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;

@SpringBootTest
@AutoConfigureMockMvc
public class ImageControllerTest {
    @MockBean
    private ImgService service;
    @Autowired
    private MockMvc mockMvc;

    @Test
    void testGetImageIdFound() throws Exception {
        Image mockImage = new Image(1, "mockPath", "Normal");
        doReturn(Optional.of(mockImage)).when(service).getImageById(1);
        mockMvc.perform(get("/project/image/getImage/{id}", 1)
                .accept(MediaType.APPLICATION_JSON_VALUE))
                .andExpect(jsonPath("$.id", Matchers.is(1)));
    }
}

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