Refactoring role spec stuff into a dedicated parsing class

Also reworking tests to cut down on the number of patches required
by sub-classing the DataLoader() class and reworking the base object's
structure a bit to allow its use

v2/ansible/parsing/yaml/__init__.py

@@ -91,6 +91,15 @@ def load_from_file(self, file_name):
 
         return parsed_data
 
+    def path_exists(self, path):
+        return os.path.exists(path)
+
+    def is_directory(self, path):
+        return os.path.isdir(path)
+
+    def is_file(self, path):
+        return os.path.isfile(path)
+
     def _safe_load(self, stream):
         ''' Implements yaml.safe_load(), except using our custom loader class. '''
         return load(stream, AnsibleLoader)
@@ -100,7 +109,7 @@ def _get_file_contents(self, file_name):
         Reads the file contents from the given file name, and will decrypt them
         if they are found to be vault-encrypted.
         '''
-        if not os.path.exists(file_name) or not os.path.isfile(file_name):
+        if not self.path_exists(file_name) or not self.is_file(file_name):
             raise AnsibleParserError("the file_name '%s' does not exist, or is not readable" % file_name)
 
         show_content = True

v2/ansible/playbook/base.py

@@ -29,13 +29,11 @@
 
 class Base:
 
-    _tags = FieldAttribute(isa='list')
-    _when = FieldAttribute(isa='list')
+    def __init__(self):
 
-    def __init__(self, loader=DataLoader):
-
-        # the data loader class is used to parse data from strings and files
-        self._loader = loader()
+        # initialize the data loader, this will be provided later
+        # when the object is actually loaded
+        self._loader = None
 
         # each class knows attributes set upon it, see Task.py for example
         self._attributes = dict()
@@ -61,11 +59,17 @@ def munge(self, ds):
 
         return ds
 
-    def load_data(self, ds):
+    def load_data(self, ds, loader=None):
         ''' walk the input datastructure and assign any values '''
 
         assert ds is not None
 
+        # the data loader class is used to parse data from strings and files
+        if loader is not None:
+            self._loader = loader
+        else:
+            self._loader = DataLoader()
+
         if isinstance(ds, string_types) or isinstance(ds, FileIO):
             ds = self._loader.load(ds)
 
@@ -89,6 +93,8 @@ def load_data(self, ds):
         self.validate()
         return self
 
+    def get_loader(self):
+        return self._loader
 
     def validate(self):
         ''' validation that is done at parse time, not load time '''

v2/ansible/playbook/block.py

@@ -28,6 +28,8 @@ class Block(Base):
     _block     = FieldAttribute(isa='list')
     _rescue    = FieldAttribute(isa='list')
     _always    = FieldAttribute(isa='list')
+    _tags      = FieldAttribute(isa='list', default=[])
+    _when      = FieldAttribute(isa='list', default=[])
 
     # for future consideration? this would be functionally
     # similar to the 'else' clause for exceptions
@@ -43,9 +45,9 @@ def get_variables(self):
         return dict()
 
     @staticmethod
-    def load(data, role=None):
+    def load(data, role=None, loader=None):
         b = Block(role=role)
-        return b.load_data(data)
+        return b.load_data(data, loader=loader)
 
     def munge(self, ds):
         '''