Trap all JSON decoding errors; raise MultiJson::EncodeError

Closes #3

lib/multi_json.rb

@@ -1,4 +1,5 @@
 module MultiJson
+  class DecodeError < StandardError; end
   module_function
 
   # Get the current engine class.
@@ -59,7 +60,11 @@ def engine=(new_engine)
   #
   # <tt>:symbolize_keys</tt> :: If true, will use symbols instead of strings for the keys.
   def decode(string, options = {})
-    engine.decode(string, options)
+    begin
+      engine.decode(string, options)
+    rescue StandardError => exception
+      raise DecodeError, exception.inspect
+    end
   end
 
   # Encodes a Ruby object as JSON.

spec/multi_json_spec.rb

@@ -50,10 +50,16 @@ def self.encode(string)
       end
 
       describe '.decode' do
-        it 'should properly decode some json' do
+        it 'should properly decode valid JSON' do
           MultiJson.decode('{"abc":"def"}').should == {'abc' => 'def'}
         end
 
+        it 'should raise MultiJson::DecodeError on invalid JSON' do
+          lambda do
+            MultiJson.decode('{"abc"}')
+          end.should raise_error(MultiJson::DecodeError)
+        end
+
         it 'should allow for symbolization of keys' do
           MultiJson.decode('{"abc":{"def":"hgi"}}', :symbolize_keys => true).should == {:abc => {:def => 'hgi'}}
         end