Merge pull request #489 from haines/name_error

Rescue specific NameErrors when inferring classes

lib/draper/decoratable.rb

@@ -68,7 +68,8 @@ module Draper
         decorator_name = [(namespace && namespace.name), "#{prefix}Decorator"].compact.join("::")
 
         decorator_name.constantize
-      rescue NameError
+      rescue NameError => error
+        raise unless error.missing_name?(decorator_name)
         raise Draper::UninferrableDecoratorError.new(self)
       end
 

lib/draper/decorator.rb

@@ -212,8 +212,10 @@ module Draper
 
     # @return [Class] the class created by {decorate_collection}.
     def self.collection_decorator_class(namespace=nil)
-      collection_decorator_name(namespace).constantize
-    rescue NameError
+      name = collection_decorator_name(namespace)
+      name.constantize
+    rescue NameError => error
+      raise if name && !error.missing_name?(name)
       Draper::CollectionDecorator
     end
 
@@ -225,8 +227,10 @@ module Draper
     end
 
     def self.inferred_source_class
-      source_name.constantize
-    rescue NameError
+      name = source_name
+      name.constantize
+    rescue NameError => error
+      raise if name && !error.missing_name?(name)
       raise Draper::UninferrableSourceError.new(self)
     end
 

spec/draper/decoratable_spec.rb

@@ -179,6 +179,13 @@ module Draper
           expect{Model.decorator_class}.to raise_error UninferrableDecoratorError
         end
       end
+
+      context "when an unrelated NameError is thrown" do
+        it "re-raises that error" do
+          String.any_instance.stub(:constantize).and_return{Draper::Base}
+          expect{Product.decorator_class}.to raise_error NameError, /Draper::Base/
+        end
+      end
     end
 
   end

spec/draper/decorator_spec.rb

@@ -154,6 +154,13 @@ module Draper
           Decorator.decorate_collection(source, with: nil, namespace: DecoratorNamespace)
         end
       end
+
+      context "when a NameError is thrown" do
+        it "re-raises that error" do
+          String.any_instance.stub(:constantize).and_return{Draper::DecoratedEnumerableProxy}
+          expect{ProductDecorator.decorate_collection([])}.to raise_error NameError, /Draper::DecoratedEnumerableProxy/
+        end
+      end
     end
 
     describe ".decorates" do
@@ -179,20 +186,23 @@ module Draper
     end
 
     describe ".source_class" do
+      protect_class ProductDecorator
+      protect_class Namespaced::ProductDecorator
+
       context "when not set by .decorates" do
-        it "raises an error for a so-named 'Decorator'" do
+        it "raises an UninferrableSourceError for a so-named 'Decorator'" do
           expect{Decorator.source_class}.to raise_error UninferrableSourceError
         end
 
-        it "raises an error for anonymous decorators" do
+        it "raises an UninferrableSourceError for anonymous decorators" do
           expect{Class.new(Decorator).source_class}.to raise_error UninferrableSourceError
         end
 
-        it "raises an error for a decorator without a model" do
+        it "raises an UninferrableSourceError for a decorator without a model" do
           expect{OtherDecorator.source_class}.to raise_error UninferrableSourceError
         end
 
-        it "raises an error for other naming conventions" do
+        it "raises an UninferrableSourceError for other naming conventions" do
           expect{ProductPresenter.source_class}.to raise_error UninferrableSourceError
         end
 
@@ -203,6 +213,13 @@ module Draper
         it "infers namespaced sources" do
           expect(Namespaced::ProductDecorator.source_class).to be Namespaced::Product
         end
+
+        context "when an unrelated NameError is thrown" do
+          it "re-raises that error" do
+            String.any_instance.stub(:constantize).and_return{SomethingThatDoesntExist}
+            expect{ProductDecorator.source_class}.to raise_error NameError, /SomethingThatDoesntExist/
+          end
+        end
       end
     end