Fix error with implicit decanter derivation via ActiveRecord class na…

…me (#117)

* Add spec and fix for dynamically generating decanter names from an AR class

* Bump patch

* Add rails version to comment

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    decanter (3.4.1)
+    decanter (3.4.2)
       actionpack (>= 4.2.10)
       activesupport
       rails-html-sanitizer (>= 1.0.4)

lib/decanter.rb

@@ -13,7 +13,7 @@ def decanter_for(klass_or_sym)
           klass_or_sym.to_s.singularize.camelize
         else
           raise ArgumentError.new("cannot lookup decanter for #{klass_or_sym} with class #{klass_or_sym.class}")
-        end.concat('Decanter')
+        end + 'Decanter'
       begin
         decanter_name.constantize
       rescue
@@ -62,4 +62,4 @@ def config
 require 'decanter/extensions'
 require 'decanter/exceptions'
 require 'decanter/parser'
-require 'decanter/railtie' if defined?(::Rails)
+require 'decanter/railtie' if defined?(::Rails)

lib/decanter/version.rb

@@ -1,3 +1,3 @@
 module Decanter
-  VERSION = '3.4.1'.freeze
+  VERSION = '3.4.2'.freeze
 end

spec/decanter/decanter_spec.rb

@@ -102,7 +102,6 @@ def self.name
     end
 
     context 'for a class' do
-
       context 'when a corresponding decanter does not exist' do
 
         let(:foo) do
@@ -132,6 +131,20 @@ def self.name
         it 'returns the decanter' do
           expect(Decanter::decanter_for(foo)).to eq FooDecanter
         end
+
+        context 'and the class name is a frozen string' do
+          let(:foo) {
+            Class.new do
+              def self.name
+                'Foo'.freeze # ActiveRecord classes might have a frozen name (Rails 5.2.3)
+              end
+            end
+          }
+
+          it 'returns the decanter' do
+            expect(Decanter::decanter_for(foo)).to eq FooDecanter
+          end
+        end
       end
     end