How to post JSON data in rails 3 functional test

Question

I plan to use JSON data in both request and response in my project and having some problems in testing.

After searching for a while, I find the following code which uses

Answer 1

As of Rails 5, the way to do this is:

post new_widget_url, as: :json, params: { foo: "bar" }

This will also set the Content-type header correctly (to application/json).