Change behaviour of 'error' level

Author: djkirkham

lib/iris/__init__.py

@@ -224,7 +224,7 @@ def __repr__(self):
     def __setattr__(self, name, value):
         if name in self.deprecated_options:
             level = self.deprecated_options[name]
-            if level == 'error':
+            if level == 'error' and not value:
                 emsg = ("setting the 'Future' property {prop!r} has been "
                         "deprecated to be removed in a future release, and "
                         "deprecated {prop!r} behaviour has been removed. "

lib/iris/tests/unit/test_Future.py

@@ -43,22 +43,17 @@ def test_invalid_attribute(self):
         with self.assertRaises(AttributeError):
             future.numberwang = 7
 
-    def test_invalid_netcdf_promote_attributes(self):
+    def test_netcdf_promote(self):
         future = Future()
-        states = [True, False]
-        exp_emsg = "deprecated 'netcdf_promote' behaviour has been removed"
-        for state in states:
-            with self.assertRaisesRegexp(AttributeError, exp_emsg):
-                future.netcdf_promote = state
+        exp_emsg = "'Future' property 'netcdf_promote' is deprecated"
+        with self.assertWarnsRegexp(exp_emsg):
+            future.netcdf_promote = True
 
-    def test_invalid_netcdf_no_unlimited_attributes(self):
+    def test_invalid_netcdf_promote(self):
         future = Future()
-        states = [True, False]
-        exp_emsg =\
-            "deprecated 'netcdf_no_unlimited' behaviour has been removed"
-        for state in states:
-            with self.assertRaisesRegexp(AttributeError, exp_emsg):
-                future.netcdf_no_unlimited = state
+        exp_emsg = "'Future' property 'netcdf_promote' has been deprecated"
+        with self.assertRaisesRegexp(AttributeError, exp_emsg):
+            future.netcdf_promote = False
 
     def test_cell_datetime_objects(self):
         future = Future()