Abstract timeout option parsing

Rubocop told me the method started to be too complex.

lib/http/chainable.rb:94:5: C: Metrics/PerceivedComplexity: Perceived complexity for timeout is too high. [10/8]
    def timeout(options) ...
    ^^^^^^^^^^^^^^^^^^^^
80 files inspected, 1 offense detected

lib/http/chainable.rb

@@ -94,27 +94,7 @@ def timeout(options)
       klass, options = case options
                        when Numeric then [HTTP::Timeout::Global, {:global_timeout => options}]
                        when Hash
-                         options = options.dup
-                         %i[read write connect].each do |k|
-                           next unless options.key? k
-
-                           if options.key?("#{k}_timeout".to_sym)
-                             raise ArgumentError, "can't pass both #{k} and #{"#{k}_timeout".to_sym}"
-                           end
-
-                           options["#{k}_timeout".to_sym] = options.delete k
-                         end
-
-                         options.each do |key, value|
-                           unless HTTP::Timeout::PerOperation::SETTINGS.member?(key) && value.is_a?(Numeric)
-                             raise ArgumentError, "invalid option #{key.inspect}, must be numeric " \
-                                                  "`.timeout(connect: x, write: y, read: z)`."
-                           end
-                         end
-
-                         raise ArgumentError, "at least one option" if options.empty?
-
-                         [HTTP::Timeout::PerOperation, options.dup]
+                         [HTTP::Timeout::PerOperation, HTTP::Timeout::PerOperation.parse_options(options)]
                        when :null then [HTTP::Timeout::Null, {}]
                        else raise ArgumentError, "Use `.timeout(:null)`, " \
                                                  "`.timeout(global_timeout_in_seconds)` or " \

lib/http/timeout/per_operation.rb

@@ -12,6 +12,39 @@ class PerOperation < Null
       READ_TIMEOUT = 0.25
 
       SETTINGS = Set.new(%i[read_timeout write_timeout connect_timeout])
+
+      class << self
+        def parse_options(options)
+          options = options.dup.then { |opts| expand_names(opts) }
+          options.each do |key, value|
+            unless SETTINGS.member?(key) && value.is_a?(Numeric)
+              raise ArgumentError, "invalid option #{key.inspect}, must be numeric " \
+                                   "`.timeout(connect: x, write: y, read: z)`."
+            end
+          end
+
+          raise ArgumentError, "at least one option" if options.empty?
+
+          options
+        end
+
+        private
+
+        def expand_names(options)
+          %i[read write connect].each do |k|
+            next unless options.key? k
+
+            if options.key?("#{k}_timeout".to_sym)
+              raise ArgumentError, "can't pass both #{k} and #{"#{k}_timeout".to_sym}"
+            end
+
+            options["#{k}_timeout".to_sym] = options.delete k
+          end
+
+          options
+        end
+      end
+
       def initialize(*args)
         super