refactor: remove legacy schema wire-name helper

gems/smithy-schema/lib/smithy-schema/document_utils/deserializer.rb

@@ -75,8 +75,9 @@ def structure(shape, values, result = nil)
           return if values.nil?
 
           result = shape.target.type.new if result.nil?
-          shape.target.members.each do |member_name, member_shape|
-            value = values[wire_name(member_shape)]
+          Smithy::Schema::Extension.wire_index(shape.target).each do |wire_name, entry|
+            member_name, member_shape, _target_shape = entry
+            value = values[wire_name]
             result[member_name] = deserialize_shape(member_shape, value) unless value.nil?
           end
           result
@@ -100,10 +101,12 @@ def timestamp(value)
         end
 
         def union(shape, values, result = nil) # rubocop:disable Metrics/AbcSize
-          shape.target.members.each do |member_name, member_shape|
-            value = values[wire_name(member_shape)]
+          index = Smithy::Schema::Extension.wire_index(shape.target)
+          values.each do |wire_name, value|
             next if value.nil?
+            next unless (entry = index[wire_name])
 
+            member_name, member_shape, = entry
             result = shape.target.member_type(member_name) if result.nil?
             return result.new(member_name => deserialize_shape(member_shape, value))
           end
@@ -112,10 +115,6 @@ def union(shape, values, result = nil) # rubocop:disable Metrics/AbcSize
           key, value = values.first
           shape.target.member_type(:unknown).new(key, value)
         end
-
-        def wire_name(member_shape)
-          Smithy::Schema::Extension.legacy_wire_name(member_shape)
-        end
       end
     end
   end

gems/smithy-schema/lib/smithy-schema/extension.rb

@@ -232,12 +232,6 @@ def each_member(shape, &block)
           shape.members.each { |name, member| block.call(name, member) }
         end
 
-        # TODO: Remove after the remaining legacy deserializer migrates to a
-        # resolved extension index.
-        def legacy_wire_name(member)
-          member.name
-        end
-
         # Returns whether a collection may retain nil values.
         #
         # Example:

gems/smithy-schema/sig/smithy-schema/extension.rbs

@@ -26,7 +26,6 @@ module Smithy
       def self.timestamp_format: ((Shapes::Shape | Shapes::MemberShape) shape) -> (String | Symbol)
       def self.unknown_member_type: (Shapes::UnionShape shape) -> untyped
       def self.each_member: ((Shapes::StructureShape | Shapes::UnionShape) shape) ?{ (Symbol, Shapes::MemberShape) -> void } -> untyped
-      def self.legacy_wire_name: (Shapes::MemberShape member) -> String?
       def self.sparse?: ((Shapes::Shape | Shapes::MemberShape) shape) -> bool
     end
   end

gems/smithy-schema/spec/smithy-schema/extension_spec.rb

@@ -41,18 +41,6 @@ module Schema
         end
       end
 
-      describe '.legacy_wire_name' do
-        it 'returns the model name' do
-          member = Shapes::MemberShape.new(
-            target: Shapes::StringShape.new,
-            name: 'wireName',
-            traits: { 'smithy.api#jsonName' => 'jsonWireName' }
-          )
-
-          expect(described_class.legacy_wire_name(member)).to eq('wireName')
-        end
-      end
-
       describe '.sparse?' do
         it 'returns whether the sparse trait is present' do
           expect(described_class.sparse?(Shapes::ListShape.new)).to be(false)