SafeAssignment protects hash-style assignment too

CHANGELOG.md

@@ -1,6 +1,7 @@
 ## Next
 
 * [#247](https://github.com/intridea/hashie/pull/247): Fixed #stringify_keys and #symbolize_keys collision with ActiveSupport - [@bartoszkopinski](https://github.com/bartoszkopinski).
+* [#249](https://github.com/intridea/hashie/pull/249): Make SafeAssignment protect hash-style assignment too. 
 * Your contribution here.
 
 ## 3.3.2 (11/26/2014)

README.md

@@ -377,7 +377,8 @@ class SafeMash < ::Hashie::Mash
 end
 
 safe_mash = SafeMash.new
-safe_mash.zip = 'Test' # => ArgumentError
+safe_mash.zip   = 'Test' # => ArgumentError
+safe_mash[:zip] = 'test' # => still ArgumentError
 ```
 
 ## Dash

lib/hashie/extensions/mash/safe_assignment.rb

@@ -2,10 +2,13 @@ module Hashie
   module Extensions
     module Mash
       module SafeAssignment
-        def assign_property(name, value)
-          fail ArgumentError, "The property #{name} clashes with an existing method." if methods.include?(name.to_sym)
+        def custom_writer(key, *args) #:nodoc:
+          fail ArgumentError, "The property #{key} clashes with an existing method." if methods.include?(key.to_sym)
+          super
+        end
 
-          self[name] = value
+        def []=(*args)
+          custom_writer(*args)
         end
       end
     end

spec/hashie/extensions/mash/safe_assignment_spec.rb

@@ -13,5 +13,12 @@ class MashWithSafeAssignment < Hashie::Mash
         expect { subject.zip = 'Test' }.to raise_error(ArgumentError)
       end
     end
+
+    context 'when setting as a hash key' do
+      it 'still raises if conflicts with a method' do
+        expect { subject[:zip] = 'Test' }.to raise_error(ArgumentError)
+      end
+    end
+
   end
 end