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

Answer 2

None of the answers provides a nice maintainable way to verify a JSON response. I find this one to be the best:

https://github.com/ruby-json-schema/json-schema

It provides a nice implementation for the standard json schema

You can write a schema like:

schema = {
    "type"=>"object",
    "required" => ["a"],
    "properties" => {
        "a" => {
            "type" => "integer",
            "default" => 42
        },
        "b" => {
            "type" => "object",
            "properties" => {
                "x" => {
                    "type" => "integer"
                }
            }
        }
    }
}

and use it like: JSON::Validator.validate(schema, { "a" => 5 })

Best way to verify it against my android client implementation.

Answer 3

Rails has JSON support built in:

def json_response
    ActiveSupport::JSON.decode @response.body
end

No need for a plugin

Then you can do something like this:

assert_equal "Mike", json_response['name']