Don't leak derivatives versions compat setting

When we extend Shrine::Plugins::Derivatives::AttacherMethods with
additional behavior, that gets applied to all other uploaders that have
loaded the derivatives plugin, not just the one that enabled versions
compatibility. So, we instead extend only the attacher class of the
current uploader.

CHANGELOG.md

@@ -1,5 +1,7 @@
 ## HEAD
 
+* `derivatives` – Don't leak `versions_compatibility: true` setting into other uploaders (@janko)
+
 * `remove_attachment` – Fix passing boolean values being broken in Ruby 3.2 (@janko)
 
 * `model` – When duplicating a record, make the duplicated attacher reference the duplicated record (@janko)

lib/shrine/plugins/derivatives.rb

@@ -12,18 +12,18 @@ module Derivatives
         }.inspect}"
       end
 
-      def self.load_dependencies(uploader, versions_compatibility: false, **)
+      def self.load_dependencies(uploader, **)
         uploader.plugin :default_url
-
-        AttacherMethods.prepend(VersionsCompatibility) if versions_compatibility
       end
 
-      def self.configure(uploader, log_subscriber: LOG_SUBSCRIBER, **opts)
+      def self.configure(uploader, log_subscriber: LOG_SUBSCRIBER, versions_compatibility: false, **opts)
         uploader.opts[:derivatives] ||= { processors: {}, processor_settings: {}, storage: proc { store_key }, mutex: true }
         uploader.opts[:derivatives].merge!(opts)
 
         # instrumentation plugin integration
         uploader.subscribe(:derivatives, &log_subscriber) if uploader.respond_to?(:subscribe)
+
+        uploader::Attacher.include(VersionsCompatibility) if versions_compatibility
       end
 
       module AttachmentMethods

test/plugin/derivatives_test.rb

@@ -1413,6 +1413,12 @@
           assert_equal Hash.new, @attacher.derivatives
         end
       end
+
+      it "doesn't affect other uploaders" do
+        @attacher = attacher { plugin :derivatives }
+
+        refute_includes @attacher.class.ancestors, Shrine::Plugins::Derivatives::VersionsCompatibility
+      end
     end
 
     it "can be marshalled without mutex" do