refactor raise error to lower perceived complexity

Author: gregsaab

lib/slack/web/faraday/response/raise_error.rb

@@ -4,19 +4,33 @@ module Web
     module Faraday
       module Response
         class RaiseError < ::Faraday::Middleware
-          def on_complete(env)
+          def throw_if_too_many_requests(env)
             raise Slack::Web::Api::Errors::TooManyRequestsError, env.response if env.status == 429
+          end
+
+          def throw_if_response_is_invalid_json(env)
+            return unless !response_content_type_is_a_string?(env) && !env.body.is_a?(Hash)
+
+            raise ::Faraday::ParsingError.new(nil, env.response)
+          end
 
-            response_content_type_is_string = env.response&.headers&.[]('content-type')&.include?('text/plain') || false
+          def response_content_type_is_a_string?(env)
+            env.response&.headers&.[]('content-type')&.include?('text/plain') || false
+          end
 
-            raise ::Faraday::ParsingError.new(nil, env.response) if !response_content_type_is_string && !env.body.is_a?(Hash)
+          def should_return?(env)
+            body = env.body
+            (env.success? && body.is_a?(String) && response_content_type_is_a_string?(env)) || !body || body['ok']
+          end
+
+          def on_complete(env)
+            throw_if_too_many_requests(env)
+            throw_if_response_is_invalid_json(env)
 
             return unless env.success?
 
             body = env.body
-            return if env.success? && body.is_a?(String) && response_content_type_is_string
-            return unless body
-            return if body['ok']
+            return if should_return?(env)
 
             error_message = body['error'] || body['errors'].map { |message| message['error'] }.join(',')
             error_class = Slack::Web::Api::Errors::ERROR_CLASSES[error_message]