bug fix for #372

motion/core/persistence.rb

@@ -1,6 +1,7 @@
 # Persistence module built on top of NSUserDefaults
 module BubbleWrap
   module Persistence
+    class FailSynchronize < RuntimeError; end
     module_function
 
     def app_key
@@ -9,7 +10,11 @@ def app_key
 
     def []=(key, value)
       storage.setObject(value, forKey: storage_key(key))
-      storage.synchronize
+      if storage.synchronize
+        value
+      else
+        raise FailSynchronize
+      end
     end
 
     def [](key)

spec/motion/core/persistence_spec.rb

@@ -30,6 +30,21 @@ def storage.synchronize; @sync_was_called = true; end
       BubbleWrap::Persistence['arbitraryNumber'] = 42
       storage.instance_variable_get(:@sync_was_called).should.equal true
     end
+
+    it 'return persisted objects' do
+      persisted_number = (BubbleWrap::Persistence['arbitraryNumber'] ||= 42)
+      persisted_number.should.equal 42
+    end
+
+    it 'raise error if fail synchronize.' do
+      storage = NSUserDefaults.standardUserDefaults
+      def storage.synchronize; false; end
+
+      lambda do 
+        BubbleWrap::Persistence['arbitraryNumber'] = 42
+      end.
+        should.raise(BubbleWrap::Persistence::FailSynchronize)
+    end
   end
 
   describe "storing multiple objects" do