request.accept = "application/json"

get '/my/path'

get '/my/path.json'

get '/my/path', nil, {'HTTP_ACCEPT' => "application/json"}

@request.env['HTTP_ACCEPT'] = "*/*, application/youtube-client"
get :index

header 'X_YOUR_HEADER_VAR', 'val'
get '/path'

get :index, :format => 'json'

request.headers["Accept"] = "application/json"

{"Accept" => "application/json"}

headers = { "HTTP_ACCEPT": "application/json" }
get my_path, xhr: true, headers: my_headers

post :save, {format: :json, application: {param1: "test", param2: "test"}}