fix: correct issue with many_to_many when one of the models has a prefix to the intersection model association (#449)

Author: bguban

lib/graphiti/adapters/active_record/many_to_many_sideload.rb

@@ -1,7 +1,6 @@
 class Graphiti::Adapters::ActiveRecord::ManyToManySideload < Graphiti::Sideload::ManyToMany
   def through_table_name
-    @through_table_name ||= parent_resource_class.model
-      .reflections[through.to_s].klass.table_name
+    @through_table_name ||= resource_class.model.reflections[through.to_s].klass.table_name
   end
 
   def through_relationship_name

spec/fixtures/legacy.rb

@@ -95,6 +95,16 @@
     t.integer :mentor_id
     t.integer :mentee_id
   end
+
+  create_table :sales_shops do |t|
+    t.string :name
+  end
+
+  create_table :sales_stocks do |t|
+    t.integer :book_id
+    t.integer :shop_id
+    t.integer :amount
+  end
 end
 
 module Legacy
@@ -186,6 +196,8 @@ class Book < ApplicationRecord
     has_many :tags, through: :taggings
     has_many :readerships
     has_many :readers, through: :readerships, source: :user
+    has_many :sales_stocks, class_name: "Legacy::Sales::Stock"
+    has_many :sales_shops, class_name: "Legacy::Sales::Shop", through: :sales_stocks, source: :shop
   end
 
   class User < ApplicationRecord
@@ -208,6 +220,22 @@ class Tagging < ApplicationRecord
     belongs_to :tag
   end
 
+  module Sales
+    def self.table_name_prefix
+      "sales_"
+    end
+
+    class Stock < ApplicationRecord
+      belongs_to :book
+      belongs_to :shop
+    end
+
+    class Shop < ApplicationRecord
+      has_many :stocks
+      has_many :books, through: :stocks, inverse_of: :sales_shops
+    end
+  end
+
   class LegacyApplicationSerializer < Graphiti::Serializer
   end
 
@@ -245,6 +273,20 @@ class BookResource < ApplicationResource
     many_to_many :readers, resource: Legacy::UserResource
   end
 
+  module Sales
+    class StockResource < ApplicationResource
+      attribute :amount, :integer
+      belongs_to :book
+      belongs_to :shop
+    end
+
+    class ShopResource < ApplicationResource
+      attribute :name, :string
+      has_many :stocks
+      many_to_many :books, resource: Legacy::BookResource, foreign_key: {sales_stocks: :shop_id}
+    end
+  end
+
   class StateResource < ApplicationResource
     attribute :name, :string
     attribute :abbreviation, :string do

spec/integration/rails/finders_spec.rb

@@ -1286,6 +1286,21 @@ def resource
         expect(author2_hobbies.size).to eq(1)
       end
 
+      context "when sideloads non-namespace model via a namespace model" do
+        let(:shop) { Legacy::Sales::Shop.create(name: "shop") }
+
+        before do
+          allow(Legacy::Sales::ShopResource).to receive(:validate_endpoints?) { false }
+          allow(controller).to receive(:resource).and_return(Legacy::Sales::ShopResource)
+          Legacy::Sales::Stock.create(shop_id: shop.id, book_id: book1.id, amount: 2)
+        end
+
+        it "works" do
+          do_index({include: "books"})
+          expect(included("books").map(&:id)).to eq([book1.id])
+        end
+      end
+
       context "when configured as a has_many association" do
         before do
           @orig_sideload = Legacy::AuthorResource.sideloads.delete(:hobbies)