class Faraday::Request::Json

Doesn’t try to encode bodies that already are in string form.
to JSON MIME-type.
If a request doesn’t have a type but has a body, it sets the Content-type
Processes only requests with matching Content-type or those without a type.
Request middleware that encodes the body as JSON.

def body?(env) 

def body?(env)
  (body = env[:body]) && !(body.respond_to?(:to_str) && body.empty?)
end

def encode(data) 

def encode(data)
  ::JSON.generate(data)
end

def match_content_type(env) 

def match_content_type(env)
  return unless process_request?(env)
  env[:request_headers][CONTENT_TYPE] ||= MIME_TYPE
  yield env[:body] unless env[:body].respond_to?(:to_str)
end

def on_request(env) 

def on_request(env)
  match_content_type(env) do |data|
    env[:body] = encode(data)
  end
end

def process_request?(env) 

def process_request?(env)
  type = request_type(env)
  body?(env) && (type.empty? || type.match?(MIME_TYPE_REGEX))
end

def request_type(env) 

def request_type(env)
  type = env[:request_headers][CONTENT_TYPE].to_s
  type = type.split(';', 2).first if type.index(';')
  type
end