POST with application/x-www-form-urlencoded is generating request snippets with content in body and query string params

[jarheadjred]

I have an application with a simple zuul route that forwards to another service.

I've setup a RestDoc test to invoke the routed path with a POST and content.

mockMvc.perform(
   post("/ivr/auth/brand/{brand}/protocol/openid-connect/token", "mybrand")
      .contextPath("/ivr")
      .contentType(MediaType.APPLICATION_FORM_URLENCODED)                        
      .content("grant_type=client_credentials&client_id=democlient&client_secret=43310292-83d4-44f4-9b47-6536f0d6f6f6"))
   .andExpect(
      status().isOk())
   .andDo(document("authentication-token-example") 

That results in the request being successfully served, but the generated curl-request.adoc and request-fields.adoc having the body documented correctly but it incorrectly appends the parameters onto the query string.

[source,bash]
----
$ curl 'https://localhost:8080/ivr/auth/brand/mybrand/protocol/openid-connect/token?grant_type=client_credentials&client_id=democlient&client_secret=43310292-83d4-44f4-9b47-6536f0d6f6f6' -i -X POST \
    -H 'Content-Type: application/x-www-form-urlencoded;charset=UTF-8' \
    -d 'grant_type=client_credentials&client_id=democlient&client_secret=43310292-83d4-44f4-9b47-6536f0d6f6f6'
----

When I try to use the perform().param() syntax to provide the form data instead of the .perform.content() then my request fails as there seems to be some incompatibility with the way that the org.springframework.cloud.netflix.zuul.filters.pre.FormBodyWrapperFilter interacts with a org.springframework.mock.web.MockHttpServletRequest

Any ideas on how I can get the generated snippets for the request to not add the form parameters as query string parameters?

[wilkinsona]

What version of REST Docs are you using?

[jarheadjred]

Here are my gradle dependencies snippets for applicable libraries:

+--- org.springframework.boot:spring-boot-starter-web: -> 2.0.2.RELEASE (*)
+--- org.springframework.cloud:spring-cloud-starter-netflix-zuul: -> 2.0.0.RC2
+--- org.springframework.restdocs:spring-restdocs-mockmvc: -> 2.0.1.RELEASE
+--- org.springframework.cloud:spring-cloud-contract-wiremock: -> 2.0.0.RC2

I think there is an incompatibility with how MockMvc handles forwarded requests. I see it's not really suported. But, it generally works from the restdocs perspective when I pass querystring params in the url, and when I pass the form content as body. If I try using post(...).params(...) then I can only make assertions on the MockMvcResultMatchers.forwarded* related parts.

[jarheadjred]

Here is a small demo project https://github.com/jarheadjred/spring-restdocs-zuul-issue

[wilkinsona]

Thanks for the sample. I've successfully reproduced the problem.

Both MockMvc and WebTestClient are affected with the root cause being that the parameters from a URL-encoded form data request body into the request's parameters. In the MockMvc case this is done by the request builder in Spring Framework. In the WebTestClient case it's done by REST Docs and has been since the WebTestClient support was first introduced.

In terms of the generated snippets, three are affected:

Curl request:

[source,bash]
----
$ curl 'https://api.mydomain.com/api/auth/brand/demobrand/protocol/openid-connect/token?grant_type=client_credentials&client_id=pub-ivr-democlient&client_secret=470d588e-29b9-4f10-a04b-28f52addfb25' -i -X POST \
    -H 'Content-Type: application/x-www-form-urlencoded;charset=UTF-8' \
    -d 'grant_type=client_credentials&client_id=pub-ivr-democlient&client_secret=470d588e-29b9-4f10-a04b-28f52addfb25'
----

HTTP request:

[source,http,options="nowrap"]
----
POST /api/auth/brand/demobrand/protocol/openid-connect/token?grant_type=client_credentials&client_id=pub-ivr-democlient&client_secret=470d588e-29b9-4f10-a04b-28f52addfb25 HTTP/1.1
Content-Type: application/x-www-form-urlencoded;charset=UTF-8
Host: api.mydomain.com
Content-Length: 109

grant_type=client_credentials&client_id=pub-ivr-democlient&client_secret=470d588e-29b9-4f10-a04b-28f52addfb25
----

HTTPie request:

[source,bash]
----
$ echo 'grant_type=client_credentials&client_id=pub-ivr-democlient&client_secret=470d588e-29b9-4f10-a04b-28f52addfb25' | http POST 'https://api.mydomain.com/api/auth/brand/demobrand/protocol/openid-connect/token?grant_type=client_credentials&client_id=pub-ivr-democlient&client_secret=470d588e-29b9-4f10-a04b-28f52addfb25' \
    'Content-Type:application/x-www-form-urlencoded;charset=UTF-8'
----