Pass an array through our stack, don't bother converting back & forth

Users aren't likely to pass non-array values here anyway.

activestorage/app/models/active_storage/blob.rb

@@ -154,7 +154,7 @@ class ActiveStorage::Blob < ActiveStorage::Record
       content_type ||= blobs.pluck(:content_type).compact.first
 
       new(filename: filename, content_type: content_type, metadata: metadata, byte_size: blobs.sum(&:byte_size)).tap do |combined_blob|
-        combined_blob.compose(*blobs.pluck(:key))
+        combined_blob.compose(blobs.pluck(:key))
         combined_blob.save!
       end
     end
@@ -268,9 +268,9 @@ class ActiveStorage::Blob < ActiveStorage::Record
     service.upload key, io, checksum: checksum, **service_metadata
   end
 
-  def compose(*keys) # :nodoc:
+  def compose(keys) # :nodoc:
     self.composed = true
-    service.compose(*keys, key, **service_metadata)
+    service.compose(keys, key, **service_metadata)
   end
 
   # Downloads the file associated with this blob. If no block is given, the entire file is read into memory and returned.

activestorage/lib/active_storage/service.rb

@@ -91,7 +91,7 @@ module ActiveStorage
     end
 
     # Concatenate multiple files into a single "composed" file.
-    def compose(*source_keys, destination_key, filename: nil, content_type: nil, disposition: nil, custom_metadata: {})
+    def compose(source_keys, destination_key, filename: nil, content_type: nil, disposition: nil, custom_metadata: {})
       raise NotImplementedError
     end
 

activestorage/lib/active_storage/service/azure_storage_service.rb

@@ -107,7 +107,7 @@ module ActiveStorage
       { "Content-Type" => content_type, "Content-MD5" => checksum, "x-ms-blob-content-disposition" => content_disposition, "x-ms-blob-type" => "BlockBlob", **custom_metadata_headers(custom_metadata) }
     end
 
-    def compose(*source_keys, destination_key, filename: nil, content_type: nil, disposition: nil, custom_metadata: {})
+    def compose(source_keys, destination_key, filename: nil, content_type: nil, disposition: nil, custom_metadata: {})
       content_disposition = content_disposition_with(type: disposition, filename: filename) if disposition && filename
 
       client.create_append_blob(

activestorage/lib/active_storage/service/disk_service.rb

@@ -100,7 +100,7 @@ module ActiveStorage
       File.join root, folder_for(key), key
     end
 
-    def compose(*source_keys, destination_key, **)
+    def compose(source_keys, destination_key, **)
       File.open(make_path_for(destination_key), "w") do |destination_file|
         source_keys.each do |source_key|
           File.open(path_for(source_key), "rb") do |source_file|

activestorage/lib/active_storage/service/gcs_service.rb

@@ -134,7 +134,7 @@ module ActiveStorage
       headers
     end
 
-    def compose(*source_keys, destination_key, filename: nil, content_type: nil, disposition: nil, custom_metadata: {})
+    def compose(source_keys, destination_key, filename: nil, content_type: nil, disposition: nil, custom_metadata: {})
       bucket.compose(source_keys, destination_key).update do |file|
         file.content_type = content_type
         file.content_disposition = content_disposition_with(type: disposition, filename: filename) if disposition && filename

activestorage/lib/active_storage/service/s3_service.rb

@@ -95,7 +95,7 @@ module ActiveStorage
       { "Content-Type" => content_type, "Content-MD5" => checksum, "Content-Disposition" => content_disposition, **custom_metadata_headers(custom_metadata) }
     end
 
-    def compose(*source_keys, destination_key, filename: nil, content_type: nil, disposition: nil, custom_metadata: {})
+    def compose(source_keys, destination_key, filename: nil, content_type: nil, disposition: nil, custom_metadata: {})
       content_disposition = content_disposition_with(type: disposition, filename: filename) if disposition && filename
 
       object_for(destination_key).upload_stream(

activestorage/test/service/shared_service_tests.rb

@@ -153,7 +153,7 @@ module ActiveStorage::Service::SharedServiceTests
         )
       end
       destination_key = SecureRandom.base58(24)
-      @service.compose(*keys, destination_key)
+      @service.compose(keys, destination_key)
 
       assert_equal "Together", @service.download(destination_key)
     end