Add filter for ActiveRecord::Relation to stop preloading

Author: antulik

lib/active_interaction/extras.rb

@@ -111,6 +111,7 @@ def include_errors!(model, **mapping)
 end
 
 require 'active_interaction/extras/filters/anything_filter'
+require 'active_interaction/extras/filters/ar_relation_filter'
 require 'active_interaction/extras/filters/uuid_filter'
 
 I18n.load_path.unshift(

lib/active_interaction/extras/filters/ar_relation_filter.rb

@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+class ActiveInteraction::Extras::Filters::ArRelationFilter < ActiveInteraction::ObjectFilter
+  register :ar_relation
+
+  def initialize(...)
+    super
+    @options.reverse_merge!(class: ActiveRecord::Relation)
+  end
+
+  def matches?(value)
+    # value == nil triggers active record loading
+    if value.nil? && default?
+      # as per v5 there is no way to know if value of `nil` is given by caller or
+      # is a default value when it's missing. We want to maintain standard default
+      # behaviour when value is `nil`. Returning `false` will trigger default value
+      false
+    else
+      true
+    end
+  end
+end