utils/types: better enum class member setting

- What used to be enum.values is now enum.levels.
- Add enum.names and enum.values that are lists of enum's levels' names
  and values respectively.
- Add a check on creation to make sure that provided level names do not
  conflict with the atomatically created members.

tests/test_utils.py

@@ -107,6 +107,14 @@ class TestEnumLevel(TestCase):
         e = enum(['one', 'two', 'three'], start=-10, step=10)
         assert_list_equal(e.values, [-10, 0, 10])
 
+    def test_enum_name_conflicts(self):
+        assert_raises(ValueError, enum, ['names', 'one', 'two'])
+
+        e = enum(['NAMES', 'one', 'two'])
+        assert_in('names', e.levels)
+        assert_list_equal(e.names, ['names', 'one', 'two'])
+        assert_equal(e.NAMES, 'names')
+
     def test_enum_behavior(self):
         e = enum(['one', 'two', 'three'])
 
@@ -118,9 +126,9 @@ class TestEnumLevel(TestCase):
         assert_not_equal(e.one, '0')
 
         # ditto for enum membership tests
-        assert_in('one', e.values)
-        assert_in(2, e.values)
-        assert_not_in('five', e.values)
+        assert_in('one', e.levels)
+        assert_in(2, e.levels)
+        assert_not_in('five', e.levels)
 
         # The same level object returned, only when
         # passing in a valid level name/value.

wa/framework/configuration/core.py

@@ -741,7 +741,7 @@ class RunConfiguration(Configuration):
             'retry_on_status',
             kind=list_of(Status),
             default=['FAILED', 'PARTIAL'],
-            allowed_values=Status.values[Status.RUNNING.value:],
+            allowed_values=Status.levels[Status.RUNNING.value:],
             description='''
             This is list of statuses on which a job will be considered to have
             failed and will be automatically retried up to ``max_retries``

wa/framework/instrumentation.py

@@ -186,7 +186,7 @@ def priority(priority):
         def wrapper(*args, **kwargs):
             return func(*args, **kwargs)
         wrapper.func_name = func.func_name
-        if priority in Priority.values:
+        if priority in Priority.levels:
             wrapper.priority = Priority(priority)
         else:
             if not isinstance(priority, int):

wa/utils/types.py

@@ -557,7 +557,7 @@ def enum(args, start=0, step=1):
         @classmethod
         def from_pod(cls, pod):
             lv = level.from_pod(pod)
-            for enum_level in cls.values:
+            for enum_level in cls.levels:
                 if enum_level == lv:
                     return enum_level
             msg = 'Unexpected value "{}" for enum.'
@@ -574,16 +574,24 @@ def enum(args, start=0, step=1):
 
             raise ValueError('Invalid enum value: {}'.format(repr(name)))
 
+    reserved = ['values', 'levels', 'names']
+
     levels = []
     n = start
     for v in args:
-        name = caseless_string(identifier(v))
+        id_v = identifier(v)
+        if id_v in reserved:
+            message = 'Invalid enum level name "{}"; must not be in {}'
+            raise ValueError(message.format(v, reserved))
+        name = caseless_string(id_v)
         lv = level(v, n)
         setattr(Enum, name, lv)
         levels.append(lv)
         n += step
 
-    setattr(Enum, 'values', levels)
+    setattr(Enum, 'levels', levels)
+    setattr(Enum, 'values', [lv.value for lv in levels])
+    setattr(Enum, 'names', [lv.name for lv in levels])
 
     return Enum