Add tests for delegations to same model

Author: kbrock

spec/db/models.rb

@@ -5,6 +5,9 @@ class VirtualTotalTestBase < ActiveRecord::Base
 end
 
 class Author < VirtualTotalTestBase
+  # basically a :parent_id relationship
+  belongs_to :teacher, :foreign_key => :teacher_id, :class_name => "Author"
+  has_many :students, :foreign_key => :teacher_id, :class_name => "Author"
   has_many :books
   has_many :ordered_books,   -> { ordered },   :class_name => "Book"
   has_many :published_books, -> { published }, :class_name => "Book"
@@ -36,6 +39,9 @@ class Author < VirtualTotalTestBase
   virtual_sum :sum_recently_published_books_rating, :recently_published_books, :rating
   virtual_delegate :description, :to => :current_photo, :prefix => true, :type => :string
   virtual_delegate :description, :to => :fancy_photo, :prefix => true, :type => :string
+  # delegate to parent relationship
+  virtual_delegate :name, :to => :teacher, :prefix => true, :type => :string
+  virtual_delegate :teacher_name, :to => :teacher, :prefix => true, :type => :string
 
   # This is here to provide a virtual_total of a virtual_has_many that depends upon an array of associations.
   # NOTE: this is tailored to the use case and is not an optimal solution

spec/db/schema.rb

@@ -4,6 +4,7 @@
   self.verbose = false
 
   create_table "authors", :force => true do |t|
+    t.integer  "teacher_id", :index => true
     t.string   "name"
     t.string   "nickname"
   end

spec/virtual_delegates_spec.rb

@@ -26,6 +26,17 @@
     expect(tcs.map(&:x)).to match_array([nil, 4])
   end
 
+  # NOTE: this is intentonally delegating to self. Testing table aliases
+  it "double delegates to parent information" do
+    g = Author.create(:name => "grand")
+    p = Author.create(:name => "parent", :teacher_id => g.id)
+    Author.create(:name => "c1", :teacher_id => p.id)
+    Author.create(:name => "c2", :teacher_id => p.id)
+
+    ret = Author.select(:name, :teacher_teacher_name, :teacher_name).order(:id).where(:teacher_id => p.id)
+    expect(ret.map { |c| [c.teacher_teacher_name, c.teacher_name, c.name]}).to eq([["grand", "parent", "c1"],["grand", "parent", "c2"]])
+  end
+
   context "invalid" do
     it "expects a ':to' for delegation" do
       expect do