[TIP] Generator methods and nose: a bit lost...

[Fernando Perez]

Mmmhh, here we go again.  I'm now confused by why this bit doesn't work:

"""Simple example of test generators in nose"""

import nose.tools as nt

def assert_true(*a,**kw):
    return nt.assert_true(*a,**kw)

class Test1(object):

    def setup(self):
        self.x = 1

    def test_a(self):
        "t1"
        nt.assert_equals(self.x, 1)

    # A test generator - no docstring so nose reports arguments
    def testgen1(self):
        for i in range(2):
            yield assert_true,True

    # Another test generator, this one tries to access the instance
    def testgen2(self):
        yield assert_true, self.x==1

#################### EOF

When I run that simple code, the second tesgen fails:

uqbar[python]> nosetests -vv test_nosegen.py
t1 ... ok
test_nosegen.Test1.testgen1(True,) ... ok
test_nosegen.Test1.testgen1(True,) ... ok
ERROR

======================================================================
ERROR: test suite
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/fperez/usr/local/lib/python2.5/site-packages/nose-0.10.4-py2.5.egg/nose/suite.py",
line 154, in run
    self.setUp()
  File "/home/fperez/usr/local/lib/python2.5/site-packages/nose-0.10.4-py2.5.egg/nose/suite.py",
line 180, in setUp
    if not self:
  File "/home/fperez/usr/local/lib/python2.5/site-packages/nose-0.10.4-py2.5.egg/nose/suite.py",
line 65, in __nonzero__
    test = self.test_generator.next()
  File "/home/fperez/usr/local/lib/python2.5/site-packages/nose-0.10.4-py2.5.egg/nose/loader.py",
line 249, in generate
    for test in g():
  File "/home/fperez/code/python/test_nosegen.py", line 24, in testgen2
    yield assert_true, self.x==1
AttributeError: 'Test1' object has no attribute 'x'

----------------------------------------------------------------------
Ran 3 tests in 0.002s

FAILED (errors=1)
uqbar[python]>


So it seems like the test generators do not honor the setup part?

The nose docs don't really say much about test objects with generators
being any different than the rest, but it seems there are some
subtleties involved... Guidance or pointers to the relevant docs would
be much appreciated.

Cheers,

f