How to format Spring REST Docs in response body with mockMvc

Question

I write my API documentation with Spring REST Docs.

Code example:

@Override
public void getById(String urlTemplate, PathParametersSnippet pathParametersSnippet, Object... urlVariables) throws Exception {
    resultActions = mockMvc.perform(get(urlTemplate, urlVariables)
            .principal(principal)
            .contentType(APPLICATION_JSON))
            .andExpect(status().isOk())
            .andDo(print());

    // do..
}

But the problem is that the result of the test is answered in one line. And understanding the structure of the returned data is very difficult.

Response example:

MockHttpServletResponse:
           Status = 200
    Error message = null
          Headers = {Content-Type=[application/json;charset=UTF-8]}
     Content type = application/json;charset=UTF-8
             Body = {"creator":null,"modifier":null,"modificationTime":null,"creationTime":null,"id":100,"deleted":false,"name":"Name","description":null,"report":[{"creator":"System","modifier":"System","modificationTime":"2019-01-30T14:21:50","creationTime":"2019-01-30T14:21:50","id":1,"name":"Form name","reportType":{"creator":"System","modifier":"System","modificationTime":"2019-01-30T14:21:50","creationTime":"2019-01-30T14:21:50","id":1,"deleted":false,"name":"Raport"},"unmodifiable":true}]}
    Forwarded URL = null
   Redirected URL = null
          Cookies = []

Further, I generate documentation from the answer received and in the documentation also unformatted JSON

What am I doing wrong? How to enable formatting for json?

Answer 1

If you're not in a position to configure your application to produce pretty-printed responses, you can have REST Docs do it for you prior to them being documented. This is described in the Customizing Requests and Responses section of the documentation:

Preprocessing is configured by calling document with an OperationRequestPreprocessor, and/or an OperationResponsePreprocessor. Instances can be obtained using the static preprocessRequest and preprocessResponse methods on Preprocessors. For example:

this.mockMvc.perform(get("/")).andExpect(status().isOk())
    .andDo(document("index", preprocessRequest(removeHeaders("Foo")), 
            preprocessResponse(prettyPrint()))); 

In the case above the request is being preprocessed to remove a Foo header and the response is being preprocessed so that it appears pretty-printed.