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

Just specify appropriate content type:

post :index, '{"foo":"bar", "bool":true}', "CONTENT_TYPE" => 'application/json'

Json data should go as a string, not as a Hash. Looking at stack trace running a test you can acquire more control on request preparation: ActionDispatch::Integration::RequestHelpers.post => ActionDispatch::Integration::Session.process => Rack::Test::Session.env_for

Specifying :format does not work because request go as 'application/x-www-form-urlencoded' and json isn't parsed properly processing a request body.