[z3-five] Integration tests with Five and ZCML

[Martin Aspeli]

Hi,

We've known for some time that it's Bad™ that PloneTestCase does:

ZopeTestCase.installProduct('Five')

I discovered that if I mix any tests using PloneTestCase (and this 
statement, at module level) with any pure-Zope3 test that uses 
zope.app.testing.placelesssetup.setUp (with or without a corresponding 
.tearDown) I get strange and confusing errors even though the tests in 
question run fine if the PloneTestCase tests are separated from the 
Zope3-style ones.

Well, you told me so. But my question is, how *should* PloneTestCase be 
behaving. Bear in mind that in this case we're really talking about 
integration tests. We *want* PTC to load "all ZCML for all of Products/" 
(or at least all other products registered with installProduct()). We'd 
rather not require test authors to think about a dependency tree of ZCML 
files and load them all. For unit tests that's good, but for integration 
tests (which are sadly still the most prevalent and convenient in the 
Zope2 world - too many objects to mock, too much reliance on things like 
acquisition) we want to make sure the environment behaves as closely to 
Zope2-on-startup as is reasonable.

We've been bemoaning this problem for a long time. I'd like to get it 
out of the world once and for all. ;-)

Martin