Fix bug where ignores the option if the association is polymorphic.

Author: ElMassimo

CHANGELOG.md

@@ -1,3 +1,7 @@
+## Mongoid::Includes 2.1.0 (2017-07-03) ##
+
+*   Fix bug where `includes` ignores the `:with` option if the association is polymorphic. Thanks @nickcherry for the bug report!
+
 ## Mongoid::Includes 2.0.0 (2017-01-10) ##
 
 *   Support Mongoid 6.0.1, fixes related to [changes in Mongoid internals](https://github.com/mongodb/mongoid/pull/4326). Thanks @mityakoval and @forumd for the bug reports!

lib/mongoid/includes/inclusion.rb

@@ -43,7 +43,7 @@ def modifier
         @modifier ||= @options[:with]
       end
 
-      # Public: Preloads the documents for the relation. Users a custom block
+      # Public: Preloads the documents for the relation. Uses a custom block
       # if one was provided, or fetches them using the class and the foreign key.
       def load_documents_for(foreign_key, foreign_key_values)
         if loader
@@ -63,7 +63,7 @@ def for_class_name(class_name)
           self[:class_name] = @class_name = class_name
           self[:polymorphic], self[:as], @polymorphic, @klass = nil
           self
-        }
+        }, with: @modifier, loader: @loader
       end
     end
   end

lib/mongoid/includes/inclusions.rb

@@ -16,7 +16,14 @@ def initialize(object = [])
       # Returns the added inclusion.
       def push(metadata, options = {})
         metadata = Inclusion.new(metadata, options) unless metadata.is_a?(Inclusion)
+
+        # Ensure that an inclusion with a specified loader or modifier replaces
+        # a previously specified loader.
+        delete(metadata) if metadata.loader || metadata.modifier
+
+        # Internally it's a set so it won't add it twice.
         add(metadata)
+
         metadata
       end
 

lib/mongoid/includes/version.rb

@@ -5,6 +5,6 @@ module Mongoid
   module Includes
 
     # Public: This library will attempt to follow semantic versioning (whatever that's supposed to be).
-    VERSION = '2.0.0'
+    VERSION = '2.1.0'
   end
 end

spec/mongoid/includes/polymorphic_includes_spec.rb

@@ -0,0 +1,54 @@
+require 'spec_helper'
+
+describe Mongoid::Includes::Criteria do
+
+  describe '#includes' do
+    Given(:inclusions) { criteria.inclusions }
+
+    context 'multiple inclusions through polymorphic associations' do
+      Given(:pink_floyd) { Band.create!(name: 'Pink Floyd') }
+      Given(:jethro) { Band.create!(name: 'Jethro Tull') }
+      Given {
+        Artist.create!(name: 'David Gilmour', associated_act: pink_floyd)
+        wywh = Album.create!(name: 'Wish You Were Here', release: Date.new(1975), owner: pink_floyd)
+        Album.create!(name: 'The Dark Side of the Moon', release: Date.new(1973), owner: pink_floyd)
+
+        Artist.create!(name: 'Ian Anderson', associated_act: jethro)
+        standup = Album.create!(name: 'Stand Up', release: Date.new(1969), owner: jethro)
+        Album.create!(name: 'Aqualung', release: Date.new(1971), owner: jethro)
+
+        Song.create!(name: 'Shine On', album: wywh)
+        Song.create!(name: 'We Used to Know', album: standup)
+      }
+      Given(:criteria) {
+        Artist
+          .includes(:musicians, from: :associated_act, from_class: Band)
+          .includes(:associated_act, with: ->(bands) {
+            bands
+              .includes(:albums, with: ->(albums) { albums.gt(release: 1970) })
+              .includes(:songs, from: :albums, with: ->(songs) { songs })
+          })
+      }
+
+      describe ':with inclusions should not be overriden' do
+        When(:artists) { expect_query(5) { criteria.entries } }
+        Given(:albums) { artists.map(&:associated_act).flat_map(&:albums) }
+        Then { artists.size == 2 }
+        And {
+          expect_no_queries { albums.size == 3 } # gt(release: 1970)
+        }
+        And {
+          expect_no_queries { albums.flat_map(&:songs).size == 1 } # Only "Shine On"
+        }
+      end
+
+      describe 'should not replace an includes with an specified modifier with a generic one' do
+        Given(:inclusions) { new_criteria.inclusions.to_a }
+        When(:new_criteria) { criteria.includes(:musicians, from: :associated_act, from_class: Band) }
+        Then { inclusions.size == 2 }
+        And  { inclusions.first.nested? }
+        And  { inclusions.last.polymorphic? && inclusions.last.modifier }
+      end
+    end
+  end
+end

spec/support/models/artist.rb

@@ -5,4 +5,6 @@ class Artist
 
   has_many :albums
   has_one :musician
+
+  belongs_to :associated_act, polymorphic: true
 end