How to test JSON result from Ruby on Rails functional tests?

Question

How can I assert my Ajax request and test the JSON output from Ruby on Rails functional tests?

Answer 1

In newer versions of rails, you can leverage parsed_body to get access to this in your tests without any work.

Calling parsed_body on the response parses the response body based on the last response MIME type.

Out of the box, only :json is supported. But for any custom MIME types you've registered, you can add your own encoders...

https://api.rubyonrails.org/v5.2.1/classes/ActionDispatch/IntegrationTest.html