Use `transform_values` to avoid extra Array allocation

actionpack/lib/action_dispatch/routing/redirection.rb

@@ -65,15 +65,15 @@ def relative_path?(path)
         end
 
         def escape(params)
-          Hash[params.map { |k, v| [k, Rack::Utils.escape(v)] }]
+          params.transform_values { |v| Rack::Utils.escape(v) }
         end
 
         def escape_fragment(params)
-          Hash[params.map { |k, v| [k, Journey::Router::Utils.escape_fragment(v)] }]
+          params.transform_values { |v| Journey::Router::Utils.escape_fragment(v) }
         end
 
         def escape_path(params)
-          Hash[params.map { |k, v| [k, Journey::Router::Utils.escape_path(v)] }]
+          params.transform_values { |v| Journey::Router::Utils.escape_path(v) }
         end
     end
 

activesupport/lib/active_support/core_ext/hash/conversions.rb

@@ -208,7 +208,7 @@ def process_hash(value)
         elsif become_empty_string?(value)
           ""
         elsif become_hash?(value)
-          xml_value = Hash[value.map { |k, v| [k, deep_to_h(v)] }]
+          xml_value = value.transform_values { |v| deep_to_h(v) }
 
           # Turn { files: { file: #<StringIO> } } into { files: #<StringIO> } so it is compatible with
           # how multipart uploaded files from HTML appear

activesupport/lib/active_support/core_ext/string/output_safety.rb

@@ -222,7 +222,7 @@ def *(*)
     def %(args)
       case args
       when Hash
-        escaped_args = Hash[args.map { |k, arg| [k, html_escape_interpolated_argument(arg)] }]
+        escaped_args = args.transform_values { |arg| html_escape_interpolated_argument(arg) }
       else
         escaped_args = Array(args).map { |arg| html_escape_interpolated_argument(arg) }
       end

railties/lib/rails/code_statistics.rb

@@ -35,7 +35,7 @@ def to_s
 
   private
     def calculate_statistics
-      Hash[@pairs.map { |pair| [pair.first, calculate_directory_statistics(pair.last)] }]
+      @pairs.transform_values { |dir| calculate_directory_statistics(dir) }
     end
 
     def calculate_directory_statistics(directory, pattern = /^(?!\.).*?\.(rb|js|coffee|rake)$/)