Make SUPPORTS_DYNAMIC an optional property, defaulting to False

octodns/source/base.py

@@ -16,13 +16,14 @@ class BaseSource(object):
         if not hasattr(self, 'SUPPORTS_GEO'):
             raise NotImplementedError('Abstract base class, SUPPORTS_GEO '
                                       'property missing')
-        if not hasattr(self, 'SUPPORTS_DYNAMIC'):
-            raise NotImplementedError('Abstract base class, SUPPORTS_DYNAMIC '
-                                      'property missing')
         if not hasattr(self, 'SUPPORTS'):
             raise NotImplementedError('Abstract base class, SUPPORTS '
                                       'property missing')
 
+    @property
+    def SUPPORTS_DYNAMIC(self):
+        return False
+
     def populate(self, zone, target=False, lenient=False):
         '''
         Loads all records the provider knows about for the provided zone

tests/test_octodns_provider_base.py

@@ -61,27 +61,29 @@ class TestBaseProvider(TestCase):
         class HasSupportsGeo(HasLog):
             SUPPORTS_GEO = False
 
-        with self.assertRaises(NotImplementedError) as ctx:
-            HasSupportsGeo('hassupportsgeo')
-        self.assertEquals('Abstract base class, SUPPORTS_DYNAMIC '
-                          'property missing', ctx.exception.message)
-
-        class HasSupportsDyanmic(HasSupportsGeo):
-            SUPPORTS_DYNAMIC = False
-
         zone = Zone('unit.tests.', ['sub'])
         with self.assertRaises(NotImplementedError) as ctx:
-            HasSupportsDyanmic('hassupportsdynamic').populate(zone)
+            HasSupportsGeo('hassupportsgeo').populate(zone)
         self.assertEquals('Abstract base class, SUPPORTS property missing',
                           ctx.exception.message)
 
-        class HasSupports(HasSupportsDyanmic):
+        class HasSupports(HasSupportsGeo):
             SUPPORTS = set(('A',))
         with self.assertRaises(NotImplementedError) as ctx:
             HasSupports('hassupports').populate(zone)
         self.assertEquals('Abstract base class, populate method missing',
                           ctx.exception.message)
 
+        # SUPPORTS_DYNAMIC has a default/fallback
+        self.assertFalse(HasSupports('hassupports').SUPPORTS_DYNAMIC)
+
+        # But can be overridden
+        class HasSupportsDyanmic(HasSupports):
+            SUPPORTS_DYNAMIC = True
+
+        self.assertTrue(HasSupportsDyanmic('hassupportsdynamic')
+                        .SUPPORTS_DYNAMIC)
+
         class HasPopulate(HasSupports):
 
             def populate(self, zone, target=False, lenient=False):