Specific asserts

[zware]

This PR converts the tests from simple assert statements to TestCase.assert* calls. This ensures that the tests actually test something even if Python is run with -O, and makes the tests fit the style of the rest of the standard library tests.

Most of the changes were made by simple s/assert .../self.assert.../ replacements, with a few manual touchups.

[gvanrossum]

I would actually prefer going the other way -- change the remaining self.assertEqual(x, y) calls to assert x == y. I mostly run the tests using py.test and it much prefers the latter idiom.

Does anyone routinely run the stdlib tests with -O?

[zware]

Does anyone routinely run the stdlib tests with -O?

Not that I know of currently, but I would like for there to be buildbots running with both -O and -OO, which should be easily doable if I rewrite the build master as I recently mentioned on python-dev.

[gvanrossum]

Looks like it's not going to happen any time soon. I propose not to count on it. The rename dance TestCase -> _TestCase feels kind of awkward -- why not just pick a decent new name for TestCase + assert[Not]IsSubclass, and use that where it's needed.

[zware]

Right, the comment was not meant to imply that assertIsSubclass would eventually be a standard feature. The rename dance was an effort to avoid churn, but as you pointed out, the whole PR is pretty much churn so I'll just change it to BaseTestCase.

[gvanrossum]

OK, I concede your point (even though I don't like noisy commits -- you will end up owning all those lines in hg/git blame forever). Once this is merged here, can you take care of merging it into 3.5+3.6?

[zware]

My ownership of the lines is unfortunate, agreed.

Yes, I can sync cpython after merge here.

[bintoro]

Note that, once #136 is resolved, most issubclass assertions will have to be changed again.

[gvanrossum]

OK, go ahead and merge into CPython 3.5 and 3.6.

[zware]

Thanks, Guido. I've merged into cpython 3.5 and default.

The only remaining question is whether you want python2/test_typing.py similarly treated. I have no opinion about it, but am willing to put forth the effort to do it if you want to keep the diff between src and python2 smaller.

[gvanrossum]

Yea, please do the python2/test_typing.py -- I do try to keep them in sync. And there are plenty of PRs coming up.