fix: Return response from multipart copy_to/copy_from instead of nil

gems/aws-sdk-s3/CHANGELOG.md

@@ -1,6 +1,8 @@
 Unreleased Changes
 ------------------
 
+* Issue - Return the copy response from multipart `copy_to`/`copy_from` instead of `nil` on success.
+
 1.232.0 (2026-09-11)
 ------------------
 

gems/aws-sdk-s3/lib/aws-sdk-s3/object_multipart_copier.rb

@@ -68,6 +68,7 @@ def copy(options = {}) # rubocop:disable Metrics/AbcSize, Metrics/MethodLength
 
         put_tags(tag_set, resp, options) if tag_set
         put_annotations(annotations, resp, options) if annotations&.any?
+        resp
       end
 
       private

gems/aws-sdk-s3/spec/object/multipart_copy_spec.rb

@@ -69,6 +69,21 @@ def request_params(operation_name)
         it 'raises an error on invalid targets' do
           expect { object.copy_to(:target) }.to raise_error(ArgumentError)
         end
+
+        it 'does not return nil when a single-shot copy succeeds' do
+          resp = object.copy_to('target-bucket/target-key')
+
+          expect(resp).not_to be_nil
+        end
+
+        it 'does not return nil when a multipart copy succeeds' do
+          client.stub_responses(:head_object, client.stub_data(:head_object, content_length: 50 * 1024 * 1024))
+          client.stub_responses(:create_multipart_upload, upload_id: 'upload-id')
+
+          resp = object.copy_to('target-bucket/target-key', multipart_copy: true)
+
+          expect(resp).not_to be_nil
+        end
       end
 
       describe '#copy_from' do

gems/aws-sdk-s3/spec/object_multipart_copier_spec.rb

@@ -31,6 +31,12 @@ module S3
           copier.copy(base_options)
         end
 
+        it 'returns the complete multipart upload response' do
+          resp = copier.copy(base_options)
+
+          expect(resp).not_to be_nil
+        end
+
         it 'respects min_part_size' do
           small_copier = ObjectMultipartCopier.new(client: client, min_part_size: 10 * 1024 * 1024)
 
@@ -80,6 +86,12 @@ module S3
               copier.copy(base_options.merge(tags_directive: 'COPY'))
             end
 
+            it 'returns the copy response after applying tags' do
+              resp = copier.copy(base_options.merge(tags_directive: 'COPY'))
+
+              expect(resp).not_to be_nil
+            end
+
             it 'overrides user-supplied tags' do
               expect(client).to receive(:create_multipart_upload)
                 .with(hash_not_including(:tagging))
@@ -227,6 +239,12 @@ module S3
               copier.copy(base_options.merge(annotations_directive: 'COPY'))
             end
 
+            it 'returns the copy response after applying annotations' do
+              resp = copier.copy(base_options.merge(annotations_directive: 'COPY'))
+
+              expect(resp).not_to be_nil
+            end
+
             it 'raises on partial failure when applying annotations' do
               client.stub_responses(:put_object_annotation, [{}, 'ServiceError'])