refactor internal finalization mechanics such that all fixture arguments

in a test invocation will have a corresponding FixtureDef instance.
also fixes issue246 (again).

simplify parametrized fixture teardown by making it work lazy:
during the setup of a parametrized fixture instance any previously
setup instance which was setup with a different param is torn down
before setting up the new one.

1 files changed, 4 insertions, 0 deletions

diff --git a/_pytest/main.py b/_pytest/main.py
index 48084bab9..75cb487e4 100644
--- a/_pytest/main.py
+++ b/_pytest/main.py
@@ -230,6 +230,8 @@ class Node(object):
         #: allow adding of extra keywords to use for matching
         self.extra_keyword_matches = set()
 
+        # used for storing artificial fixturedefs for direct parametrization
+        self._name2pseudofixturedef = {}
         #self.extrainit()
 
     @property
@@ -365,6 +367,8 @@ class Node(object):
         self.session._setupstate.addfinalizer(fin, self)
 
     def getparent(self, cls):
+        """ get the next parent node (including ourself)
+        which is an instance of the given class"""
         current = self
         while current and not isinstance(current, cls):
             current = current.parent