Check arity of #to_hash before calling. Closes #144

2 files changed, 25 insertions, 3 deletions

diff --git a/lib/hashie/hash.rb b/lib/hashie/hash.rb
index 0916135..2304872 100644
--- a/lib/hashie/hash.rb
+++ b/lib/hashie/hash.rb
@@ -16,18 +16,28 @@ module Hashie
         if self[k].is_a?(Array)
           out[assignment_key] ||= []
           self[k].each do |array_object|
-            out[assignment_key] << (Hash === array_object ? array_object.to_hash(options) : array_object)
+            out[assignment_key] << (Hash === array_object ? flexibly_convert_to_hash(array_object, options) : array_object)
           end
         else
-          out[assignment_key] = Hash === self[k] ? self[k].to_hash(options) : self[k]
+          out[assignment_key] = Hash === self[k] ? flexibly_convert_to_hash(self[k], options) : self[k]
         end
       end
       out
     end
 
-    # The C geneartor for the json gem doesn't like mashies
+    # The C generator for the json gem doesn't like mashies
     def to_json(*args)
       to_hash.to_json(*args)
     end
+    
+    private
+    
+    def flexibly_convert_to_hash(object, options = {})
+      if object.method(:to_hash).arity == 0
+        object.to_hash
+      else
+        object.to_hash(options)
+      end
+    end
   end
 end
diff --git a/spec/hashie/hash_spec.rb b/spec/hashie/hash_spec.rb
index df1e557..ad92191 100644
--- a/spec/hashie/hash_spec.rb
+++ b/spec/hashie/hash_spec.rb
@@ -31,4 +31,16 @@ describe Hash do
     symbolized_hash = hash.to_hash(symbolize_keys: true)
     expect(symbolized_hash).to eq(:a => 'hey', :"123" => 'bob', :array => [1, 2, 3])
   end
+  
+  it "#to_hash should not blow up when #to_hash doesn't accept arguments" do
+    class BareCustomMash < Hashie::Mash
+      def to_hash
+        {}
+      end
+    end
+  
+    h = Hashie::Hash.new
+    h[:key] = BareCustomMash.new
+    expect{ h.to_hash }.not_to raise_error
+  end
 end