Fix #501: Imported test generators are treated as simple test functions

The issue is that `transplant_func()` did not preserve function
generators correctly.  It would wrap the transplanted function with a
decorator, and since no yield statement was present in the decorator,
we'd lose sight of whether the transplanted function was a generator
function.

To fix this, let's check whether the function is a generator function,
and if so, use a for/yield loop to pass the results back using a
generator causing the decorator function to be seen as a generator
function.  This will preserve the fact that the supplied function was a
generator function.

1 files changed, 7 insertions, 2 deletions

diff --git a/nose/util.py b/nose/util.py
index 039163a..7995700 100644
--- a/nose/util.py
+++ b/nose/util.py
@@ -609,8 +609,13 @@ def transplant_func(func, module):
 
     """
     from nose.tools import make_decorator
-    def newfunc(*arg, **kw):
-        return func(*arg, **kw)
+    if isgenerator(func):
+        def newfunc(*arg, **kw):
+            for v in func(*arg, **kw):
+                yield v
+    else:
+        def newfunc(*arg, **kw):
+            return func(*arg, **kw)
 
     newfunc = make_decorator(func)(newfunc)
     newfunc.__module__ = module