Use intermediate through factory if available

lib/rom/factory/attributes/association.rb

@@ -46,6 +46,11 @@ def dependency?(*)
         def value?
           false
         end
+
+        # @api private
+        def factories
+          builder.factories
+        end
       end
 
       # @api private
@@ -131,42 +136,6 @@ def count
         end
       end
 
-      class OneToOneThrough < Core
-        def call(attrs = EMPTY_HASH, parent, persist: true)
-          return if attrs.key?(name)
-
-          struct = if persist && attrs[tpk]
-                     attrs
-                   elsif persist
-                     builder.persistable.create(*traits, **attrs)
-                   else
-                     builder.struct(*traits, **attrs)
-                   end
-
-          assoc.persist([parent], struct) if persist
-
-          {name => struct}
-        end
-
-        def dependency?(rel)
-          assoc.source == rel
-        end
-
-        def through?
-          true
-        end
-
-        private
-
-        def count
-          options.fetch(:count, 1)
-        end
-
-        def tpk
-          assoc.target.primary_key
-        end
-      end
-
       class ManyToMany < Core
         def call(attrs = EMPTY_HASH, parent, persist: true)
           return if attrs.key?(name)
@@ -181,7 +150,14 @@ def call(attrs = EMPTY_HASH, parent, persist: true)
             end
           end
 
-          assoc.persist([parent], structs) if persist
+          # Delegate to through factory if it exists
+          if through_factory? && persist
+            structs.each do |child|
+              factories[through_factory_name, user: parent, address: child]
+            end
+          else
+            assoc.persist([parent], structs) if persist
+          end
 
           {name => structs}
         end
@@ -194,6 +170,14 @@ def through?
           true
         end
 
+        def through_factory?
+          factories.registry.key?(through_factory_name)
+        end
+
+        def through_factory_name
+          ROM::Inflector.singularize(assoc.definition.through.source).to_sym
+        end
+
         private
 
         def count
@@ -204,6 +188,9 @@ def tpk
           assoc.target.primary_key
         end
       end
+
+      class OneToOneThrough < ManyToMany
+      end
     end
   end
 end

lib/rom/factory/builder.rb

@@ -28,6 +28,10 @@ class Builder
     #   @return [Module] Custom struct namespace
     option :struct_namespace, reader: false
 
+    # @!attribute [r] factories
+    #   @return [Module] Factories with other builders
+    option :factories, reader: true, optional: true
+
     # @api private
     def tuple(*traits, **attrs)
       tuple_evaluator.defaults(traits, attrs)

lib/rom/factory/dsl.rb

@@ -50,7 +50,13 @@ def initialize(name, relation:, factories:, struct_namespace:, attributes: Attri
 
       # @api private
       def call
-        ::ROM::Factory::Builder.new(_attributes, _traits, relation: _relation, struct_namespace: _struct_namespace)
+        ::ROM::Factory::Builder.new(
+          _attributes,
+          _traits,
+          relation: _relation,
+          struct_namespace: _struct_namespace,
+          factories: _factories
+        )
       end
 
       # Delegate to a builder and persist a struct

spec/integration/rom/factory_spec.rb

@@ -109,6 +109,12 @@
           f.association :address
         end
 
+        factories.define(:user_address) do |f|
+          f.association(:user)
+          f.association(:address)
+          f.timestamps
+        end
+
         factories.define(:address) do |f|
           f.full_address "123 Elm St."
         end
@@ -909,6 +915,12 @@ class Admin < ROM::Struct
           f.association(:addresses, count: 2)
         end
 
+        factories.define(:user_address) do |f|
+          f.association(:user)
+          f.association(:address)
+          f.timestamps
+        end
+
         factories.define(:address) do |f|
           f.sequence(:full_address) { |n| "Address #{n}" }
         end

spec/shared/relations.rb

@@ -31,6 +31,8 @@
       primary_key :id
       foreign_key :user_id, :users, on_delete: :cascade
       foreign_key :address_id, :addresses, on_delete: :cascade
+      column :created_at, Time, null: false
+      column :updated_at, Time, null: false
     end
 
     conn.create_table?(:key_values) do

spec/spec_helper.rb

@@ -5,13 +5,8 @@
 require "pathname"
 SPEC_ROOT = root = Pathname(__FILE__).dirname
 
-begin
-  require "pry-byebug"
-rescue LoadError
-  require "pry"
-end
-
 require "rom-factory"
+require "byebug"
 require "rspec"
 
 Dir[root.join("support/*.rb").to_s].sort.each do |f|