Adding aliases for field attributes and renaming async attribute (#33141)

* Adding aliases for field attributes and renaming async attribute

As of Python 3.7, the use of async raises an error, whereas before the use
of the reserved word was ignored. This adds an alias field for field attrs
so that both async and async_val (interally) work. This allows us to be
backwards-compatible with 3rd party plugins that may still reference Task.async,
but for the core engine to work on Py3.7+.

* Remove files fixed for 'async' usage from the python 3.7 skip list

1 files changed, 17 insertions, 3 deletions

diff --git a/lib/ansible/playbook/base.py b/lib/ansible/playbook/base.py
index 4a27eaea6d..4beb56f55c 100644
--- a/lib/ansible/playbook/base.py
+++ b/lib/ansible/playbook/base.py
@@ -109,6 +109,11 @@ class BaseMeta(type):
                     dst_dict['_valid_attrs'][attr_name] = value
                     dst_dict['_attributes'][attr_name] = value.default
 
+                    if value.alias is not None:
+                        dst_dict[value.alias] = property(getter, setter, deleter)
+                        dst_dict['_valid_attrs'][value.alias] = value
+                        dst_dict['_alias_attrs'][value.alias] = attr_name
+
         def _process_parents(parents, dst_dict):
             '''
             Helper method which creates attributes from all parent objects
@@ -124,6 +129,7 @@ class BaseMeta(type):
         # create some additional class attributes
         dct['_attributes'] = dict()
         dct['_valid_attrs'] = dict()
+        dct['_alias_attrs'] = dict()
 
         # now create the attributes based on the FieldAttributes
         # available, including from parent (and grandparent) objects
@@ -235,12 +241,15 @@ class Base(with_metaclass(BaseMeta, object)):
         # so that certain fields can be loaded before others, if they are dependent.
         for name, attr in sorted(iteritems(self._valid_attrs), key=operator.itemgetter(1)):
             # copy the value over unless a _load_field method is defined
+            target_name = name
+            if name in self._alias_attrs:
+                target_name = self._alias_attrs[name]
             if name in ds:
                 method = getattr(self, '_load_%s' % name, None)
                 if method:
-                    self._attributes[name] = method(name, ds[name])
+                    self._attributes[target_name] = method(name, ds[name])
                 else:
-                    self._attributes[name] = ds[name]
+                    self._attributes[target_name] = ds[name]
 
         # run early, non-critical validation
         self.validate()
@@ -279,13 +288,16 @@ class Base(with_metaclass(BaseMeta, object)):
             # walk all fields in the object
             for (name, attribute) in iteritems(self._valid_attrs):
 
+                if name in self._alias_attrs:
+                    name = self._alias_attrs[name]
+
                 # run validator only if present
                 method = getattr(self, '_validate_%s' % name, None)
                 if method:
                     method(attribute, name, getattr(self, name))
                 else:
                     # and make sure the attribute is of the type it should be
-                    value = getattr(self, name)
+                    value = self._attributes[name]
                     if value is not None:
                         if attribute.isa == 'string' and isinstance(value, (list, dict)):
                             raise AnsibleParserError(
@@ -314,6 +326,8 @@ class Base(with_metaclass(BaseMeta, object)):
         new_me = self.__class__()
 
         for name in self._valid_attrs.keys():
+            if name in self._alias_attrs:
+                continue
             new_me._attributes[name] = shallowcopy(self._attributes[name])
 
         new_me._loader = self._loader