Fix multipleOf check in set_value. (#83)

Author: mrstegeman

gateway_addon/__init__.py

@@ -16,7 +16,7 @@
 from .outlet import Outlet
 from .property import Property
 
-__version__ = '0.11.0'
+__version__ = '0.12.0'
 API_VERSION = 2
 
 

gateway_addon/property.py

@@ -141,10 +141,13 @@ def set_value(self, value):
             raise PropertyError('Value greater than maximum: {}'
                                 .format(self.description['maximum']))
 
-        if 'multipleOf' in self.description and \
-                value % self.description['multipleOf'] != 0:
-            raise PropertyError('Value is not a multiple of: {}'
-                                .format(self.description['multipleOf']))
+        if 'multipleOf' in self.description:
+            # note that we don't use the modulus operator here because it's
+            # unreliable for floating point numbers
+            multiple_of = self.description['multipleOf']
+            if value / multiple_of - round(value / multiple_of) != 0:
+                raise PropertyError('Value is not a multiple of: {}'
+                                    .format(multiple_of))
 
         if 'enum' in self.description and \
                 len(self.description['enum']) > 0 and \

setup.py

@@ -29,7 +29,7 @@
 
 setup(
     name='gateway_addon',
-    version='0.11.0',
+    version='0.12.0',
     description='Bindings for Mozilla WebThings Gateway add-ons',
     long_description=long_description,
     url='https://github.com/mozilla-iot/gateway-addon-python',