Adding option to skip loading models from subdirectories (#767)

Currently, the models annotator automatically attempts to find a class with a matching name at the bottom of project's directory tree before going up into specific engine's models.  This causes issues with models that share names with classes in other engines or lower classes in the project's directory.   This PR adds the option to skip attempts to load classes from lower directories and just uses the model's file path directly. 

#674

lib/annotate/annotate_models.rb

@@ -67,6 +67,19 @@ def root_dir
 
     attr_writer :root_dir
 
+    def skip_subdirectory_model_load
+      # This option is set in options[:skip_subdirectory_model_load]
+      # and stops the get_loaded_model method from loading a model from a subdir
+
+      if @skip_subdirectory_model_load.blank?
+        false
+      else
+        @skip_subdirectory_model_load
+      end
+    end
+
+    attr_writer :skip_subdirectory_model_load
+
     def get_patterns(options, pattern_types = [])
       current_patterns = []
       root_dir.each do |root_directory|
@@ -586,8 +599,10 @@ def get_model_class(file)
 
     # Retrieve loaded model class
     def get_loaded_model(model_path, file)
-      loaded_model_class = get_loaded_model_by_path(model_path)
-      return loaded_model_class if loaded_model_class
+      unless skip_subdirectory_model_load
+        loaded_model_class = get_loaded_model_by_path(model_path)
+        return loaded_model_class if loaded_model_class
+      end
 
       # We cannot get loaded model when `model_path` is loaded by Rails
       # auto_load/eager_load paths. Try all possible model paths one by one.
@@ -616,6 +631,7 @@ def get_loaded_model_by_path(model_path)
     def parse_options(options = {})
       self.model_dir = split_model_dir(options[:model_dir]) if options[:model_dir]
       self.root_dir = options[:root_dir] if options[:root_dir]
+      self.skip_subdirectory_model_load = options[:skip_subdirectory_model_load].present?
     end
 
     def split_model_dir(option_value)

spec/lib/annotate/annotate_models_spec.rb

@@ -147,7 +147,8 @@ def mock_column(name, type, options = {})
     let(:options) do
       {
         root_dir: '/root',
-        model_dir: 'app/models,app/one,  app/two   ,,app/three'
+        model_dir: 'app/models,app/one,  app/two   ,,app/three',
+        skip_subdirectory_model_load: false
       }
     end
 
@@ -174,6 +175,40 @@ def mock_column(name, type, options = {})
         is_expected.to eq(['app/models', 'app/one', 'app/two', 'app/three'])
       end
     end
+
+    describe '@skip_subdirectory_model_load' do
+      subject do
+        AnnotateModels.instance_variable_get(:@skip_subdirectory_model_load)
+      end
+
+      context 'option is set to true' do
+        let(:options) do
+          {
+            root_dir: '/root',
+            model_dir: 'app/models,app/one,  app/two   ,,app/three',
+            skip_subdirectory_model_load: true
+          }
+        end
+
+        it 'sets skip_subdirectory_model_load to true' do
+          is_expected.to eq(true)
+        end
+      end
+
+      context 'option is set to false' do
+        let(:options) do
+          {
+            root_dir: '/root',
+            model_dir: 'app/models,app/one,  app/two   ,,app/three',
+            skip_subdirectory_model_load: false
+          }
+        end
+
+        it 'sets skip_subdirectory_model_load to false' do
+          is_expected.to eq(false)
+        end
+      end
+    end
   end
 
   describe '.get_schema_info' do
@@ -2087,6 +2122,21 @@ class Bar::Foo
           expect(klass.name).to eq('Foo')
           expect(klass_2.name).to eq('Bar::Foo')
         end
+
+        it 'attempts to load the model path without expanding if skip_subdirectory_model_load is false' do
+          allow(AnnotateModels).to receive(:skip_subdirectory_model_load).and_return(false)
+          full_path = File.join(AnnotateModels.model_dir[0], filename_2)
+          expect(File).to_not receive(:expand_path).with(full_path)
+          AnnotateModels.get_model_class(full_path)
+        end
+
+        it 'does not attempt to load the model path without expanding if skip_subdirectory_model_load is true' do
+          $LOAD_PATH.unshift(AnnotateModels.model_dir[0])
+          allow(AnnotateModels).to receive(:skip_subdirectory_model_load).and_return(true)
+          full_path = File.join(AnnotateModels.model_dir[0], filename_2)
+          expect(File).to receive(:expand_path).with(full_path).and_call_original
+          AnnotateModels.get_model_class(full_path)
+        end
       end
 
       context 'one of the classes is nested in another class' do