MONGOID-5345: Fix namespace_hierarchy method for anonymous classes (#5270)

* Fix namespace_hierarchy method for anonymous classes

* Add test case

* Update relatable.rb

* Move specs to integration and cover all relation types

Co-authored-by: shields <[email protected]>

Author: johnnyshields

lib/mongoid/association/relatable.rb

@@ -411,10 +411,15 @@ def default_inverse
       def namespace_hierarchy(mod)
         parent = Object
         hier = [parent]
-        mod.name.split('::').each do |part|
-          parent = parent.const_get(part)
-          hier << parent
+
+        # name is not present on anonymous modules
+        if mod.name
+          mod.name.split('::').each do |part|
+            parent = parent.const_get(part)
+            hier << parent
+          end
         end
+
         hier.reverse
       end
 

spec/integration/associations/belongs_to_spec.rb

@@ -12,4 +12,22 @@
       expect(child).to be_valid
     end
   end
+
+  context 'when an anonymous class defines a belongs_to association' do
+    let(:klass) do
+      Class.new do
+        include Mongoid::Document
+        belongs_to :movie
+      end
+    end
+
+    it 'loads the association correctly' do
+      expect { klass }.to_not raise_error
+      expect { klass.new.movie }.to_not raise_error
+      instance = klass.new
+      movie = Movie.new
+      instance.movie = movie
+      expect(instance.movie).to eq movie
+    end
+  end
 end

spec/integration/associations/embeds_many_spec.rb

@@ -203,4 +203,19 @@
       end
     end
   end
+
+  context 'when an anonymous class defines an embeds_many association' do
+    let(:klass) do
+      Class.new do
+        include Mongoid::Document
+        embeds_many :addresses
+      end
+    end
+
+    it 'loads the association correctly' do
+      expect { klass }.to_not raise_error
+      expect { klass.new.addresses }.to_not raise_error
+      expect(klass.new.addresses.build).to be_a Address
+    end
+  end
 end

spec/integration/associations/embeds_one_spec.rb

@@ -20,4 +20,22 @@
       end
     end
   end
+
+  context 'when an anonymous class defines an embeds_one association' do
+    let(:klass) do
+      Class.new do
+        include Mongoid::Document
+        embeds_one :address
+      end
+    end
+
+    it 'loads the association correctly' do
+      expect { klass }.to_not raise_error
+      expect { klass.new.address }.to_not raise_error
+      instance = klass.new
+      address = Address.new
+      instance.address = address
+      expect(instance.address).to eq address
+    end
+  end
 end

spec/integration/associations/has_and_belongs_to_many_spec.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe 'has_and_belongs_to_many associations' do
+
+  context 'when an anonymous class defines a has_and_belongs_to_many association' do
+    let(:klass) do
+      Class.new do
+        include Mongoid::Document
+        has_and_belongs_to_many :movies, inverse_of: nil
+      end
+    end
+
+    it 'loads the association correctly' do
+      expect { klass }.to_not raise_error
+      expect { klass.new.movies }.to_not raise_error
+      expect(klass.new.movies.build).to be_a Movie
+    end
+  end
+end