Only return valid models from get_loaded_model

This avoids cases where you have:

```
module Foobar; end;

class A
  class Foobar; end
end
```

And get_loaded_model returns Foobar even though it isn't the right thing
to do.

This was a case I ran into where the base module was autogenerated.

Author: macobo

lib/annotate/annotate_models.rb

@@ -602,7 +602,9 @@ def get_loaded_model(model_path, file)
 
     # Retrieve loaded model class by path to the file where it's supposed to be defined.
     def get_loaded_model_by_path(model_path)
-      ActiveSupport::Inflector.constantize(ActiveSupport::Inflector.camelize(model_path))
+      klass = ActiveSupport::Inflector.constantize(ActiveSupport::Inflector.camelize(model_path))
+
+      klass if klass.is_a?(Class) && klass < ActiveRecord::Base
     rescue StandardError, LoadError
       # Revert to the old way but it is not really robust
       ObjectSpace.each_object(::Class)

spec/lib/annotate/annotate_models_spec.rb

@@ -2074,7 +2074,40 @@ class Foo < ActiveRecord::Base
 
         let :file_content_2 do
           <<-EOS
-            class Bar::Foo
+            class Bar::Foo < ActiveRecord::Base
+            end
+          EOS
+        end
+
+        let :klass_2 do
+          AnnotateModels.get_model_class(File.join(AnnotateModels.model_dir[0], filename_2))
+        end
+
+        it 'finds valid model' do
+          expect(klass.name).to eq('Foo')
+          expect(klass_2.name).to eq('Bar::Foo')
+        end
+      end
+
+      context 'the class name and base name clash' do
+        let :filename do
+          'foo.rb'
+        end
+
+        let :file_content do
+          <<-EOS
+            class Foo < ActiveRecord::Base
+            end
+          EOS
+        end
+
+        let :filename_2 do
+          'bar/foo.rb'
+        end
+
+        let :file_content_2 do
+          <<-EOS
+            class Bar::Foo < ActiveRecord::Base
             end
           EOS
         end
@@ -2108,7 +2141,7 @@ class Voucher < ActiveRecord::Base
         let :file_content_2 do
           <<~EOS
             class Voucher
-              class Foo
+              class Foo < ActiveRecord::Base
               end
             end
           EOS