post always returns 415 status

[jinilover]

Sorry that I am pretty new to hspec-wai and couldn't find the answer to this problem. Therefore I posted a question here.
I have a POST test case as follows:

it "post /users sample user responds with success msg" $
  post "/users" postBody `shouldRespondWith` "wai"
where postBody = [json|{"name":"wai"}|]

It returns status_code 415, media-type not supported. I tried other ways such as:
post "/users" "" `shouldRespondWith` "wai" although this will fail, I expect it will return error message like 400, not enough input. But still, it return 415
Alternatively

post "/users" (fromValue $ object [ "name" .= "wai" ]) `shouldRespondWith` "wai"

But still returns 415.
In hspec-wai/Wai.hs, I found the post function is post path = request methodPost path [], the headers is an empty list.
Therefore I changed the test case by using request directly

request methodPost "/users" postHeader postBody `shouldRespondWith` "wai"
where postBody = [json|{"name":"wai"}|]
           postHeader = [("Content-Type", "application/json")]

It works. It seems the post func that passes empty headers doesn't work. I need to specify the content-type in the headers. Did I do something wrong?

[diegospd]

I also had the same issue. There's no way to set correct headers for post.
Redefining post to send your headers works fine

import Test.Hspec.Wai hiding(post)
import Network.HTTP.Types(methodPost)
post path = request methodPost path headers
    where headers =  [("Content-Type", "application/json")]

[jinilover]

thanks @diegospd

[ynishi]

I think API test with json is common.

How about add postJson like postHtmlForm?
https://github.com/hspec/hspec-wai/blob/master/src/Test/Hspec/Wai.hs#L139