Testing with spring-test-mvc jsonpath returns null

Question

I am using Spring's "spring-test-mvc" library to test web controllers. I have a very simple controller that returns a JSON array. Then in my test I have:

@Test
public void shouldGetAllUsersAsJson() throws Exception {
    mockMvc.perform(get("/v1/users").accept(MediaType.APPLICATION_JSON))
            .andExpect(content().mimeType(MediaType.APPLICATION_JSON))
            .andExpect(jsonPath("fName").exists());
}

The above test returns:

java.lang.AssertionError: No value for JSON path: fName

To quickly check what I actually get I ran the below test:

@Test
public void shouldPrintResults() throws Exception {
    mockMvc.perform(get("/v1/users").accept(MediaType.APPLICATION_JSON))
            .andDo(print());
}

And it returns the correct JSON array in the body of MockHttpServletResponse

I'm not sure why jsonPath is not able to see fName in the JSON array.

Answer 1

If you add the json path dependency to maven, or add the jar to your lib, then it will work. I think that Spring is not including the jsonPath dependency in the latest Spring 3.2.0 RC1 release. I'm guessing that this is the same for Spring-Test-MVC standalone project as well.

Here is the dependency for Maven:

<dependency>
    <groupId>com.jayway.jsonpath</groupId>
    <artifactId>json-path</artifactId>
    <version>0.8.1</version>
    <scope>test</scope>
</dependency>

You might also need the hamcrest library to use the jsonPath("$.test").value("test")

<dependency>
    <groupId>org.hamcrest</groupId>
    <artifactId>hamcrest-library</artifactId>
    <version>1.3</version>
    <scope>test</scope>
</dependency>

Answer 2

What does your json response body look like? You can see it by doing an .andDo(print())

You might want to try jsonPath("$.fName").

This is assuming that your json response is: {"fName":"first name"}

If your response is an array then you need jsonPath("$[0].fName") for a response like: [{"fName":"first name"},{"fName":"first name #2"}]

You can see more examples at: http://goessner.net/articles/JsonPath/