Raise exception if unknown preference is accessed

CHANGELOG.rdoc

@@ -1,5 +1,6 @@
 == master
 
+* Raise exception if unknown preference is accessed
 * Rename #set_preference to #write_preference
 * Add caching of preference lookups
 * Fix preferences being stored even if they didn't change

lib/preferences.rb

@@ -337,6 +337,7 @@ def preferences(*args)
     def preferred?(name, group = nil)
       name = name.to_s
       group = group.is_a?(Symbol) ? group.to_s : group
+      assert_valid_preference(name)
 
       value = preferred(name, group)
       preference_definitions[name].query(value)
@@ -362,6 +363,7 @@ def preferred?(name, group = nil)
     def preferred(name, group = nil)
       name = name.to_s
       group = group.is_a?(Symbol) ? group.to_s : group
+      assert_valid_preference(name)
 
       if preferences_group(group).include?(name)
         # Value for this group/name has been written, but not saved yet:
@@ -401,6 +403,7 @@ def preferred(name, group = nil)
     def write_preference(name, value, group = nil)
       name = name.to_s
       group = group.is_a?(Symbol) ? group.to_s : group
+      assert_valid_preference(name)
 
       unless changed_preferences_group(group).include?(name)
         old = clone_preference_value(name, group)
@@ -424,6 +427,12 @@ def reload(*args)
     end
 
     private
+      # Asserts that the given name is a valid preference in this model.  If it
+      # is not, then an ArgumentError exception is raised.
+      def assert_valid_preference(name)
+        raise(ArgumentError, "Unknown preference: #{name}") unless preference_definitions.include?(name)
+      end
+
       # Gets the set of preferences identified by the given group
       def preferences_group(group)
         @preferences ||= {}

test/functional/preferences_test.rb

@@ -204,6 +204,11 @@ def setup
     @user = create_user
   end
 
+  def test_should_raise_exception_if_invalid_preference_read
+    exception = assert_raise(ArgumentError) { @user.preferred(:invalid) }
+    assert_equal 'Unknown preference: invalid', exception.message
+  end
+
   def test_use_default_value_if_not_stored
     assert_equal true, @user.preferred(:notifications)
   end
@@ -321,6 +326,11 @@ def setup
     @user = create_user
   end
 
+  def test_should_raise_exception_if_invalid_preference_queried
+    exception = assert_raise(ArgumentError) { @user.preferred?(:invalid) }
+    assert_equal 'Unknown preference: invalid', exception.message
+  end
+
   def test_should_be_true_if_present
     @user.preferred_language = 'English'
     assert_equal true, @user.preferred?(:language)
@@ -423,6 +433,11 @@ def setup
     @user = create_user(:login => 'admin')
   end
 
+  def test_should_raise_exception_if_invalid_preference_written
+    exception = assert_raise(ArgumentError) { @user.write_preference(:invalid, true) }
+    assert_equal 'Unknown preference: invalid', exception.message
+  end
+
   def test_should_have_same_value_if_not_changed
     @user.write_preference(:notifications, true)
     assert_equal true, @user.preferred(:notifications)