Require typing in test-requirements.txt

[gnprice]

No description provided.

[o11c]

Mypy depends on its own local fork of typing, it does not work with python3.5's version yet.

[o11c]

Also we need to be able to say "use these requirements only if python < 3.5" (the infrastructure will be useful for enum too once we use that)

[o11c]

Also the typing package on pypi isn't available for 2.7, but mypy's is.

[gnprice]

@o11c thanks for the comments!

What are the right instructions for running tests, then? Following what's in the README, on my Ubuntu 14.04 Trusty machine, in a clean environment I get

gregprice@gregprice:~/w/mypy$ virtualenv -p python3 /tmp/asdf
Running virtualenv with interpreter /usr/bin/python3
Using base prefix '/usr'
New python executable in /tmp/asdf/bin/python3
Also creating executable in /tmp/asdf/bin/python
Installing setuptools, pip...done.
gregprice@gregprice:~/w/mypy$ . /tmp/asdf/bin/activate
(asdf)gregprice@gregprice:~/w/mypy$ pip install -r test-requirements.txt 
Downloading/unpacking flake8==2.4.1 (from -r test-requirements.txt (line 1))
  Downloading flake8-2.4.1-py2.py3-none-any.whl
Downloading/unpacking pep8>=1.5.7,!=1.6.0,!=1.6.1,!=1.6.2 (from flake8==2.4.1->-r test-requirements.txt (line 1))
  Downloading pep8-1.5.7-py2.py3-none-any.whl
Downloading/unpacking mccabe>=0.2.1,<0.4 (from flake8==2.4.1->-r test-requirements.txt (line 1))
  Downloading mccabe-0.3.1-py2.py3-none-any.whl
Downloading/unpacking pyflakes>=0.8.1,<0.9 (from flake8==2.4.1->-r test-requirements.txt (line 1))
  Downloading pyflakes-0.8.1-py2.py3-none-any.whl
Installing collected packages: flake8, pep8, mccabe, pyflakes
Successfully installed flake8 pep8 mccabe pyflakes
Cleaning up...
(asdf)gregprice@gregprice:~/w/mypy$ python3 tests.py
Traceback (most recent call last):
  File "tests.py", line 3, in <module>
    from mypy.myunit import Suite, run_test
  File "/home/gregprice/w/mypy/mypy/myunit.py", line 6, in <module>
    from typing import List, Tuple, Any, Callable, Union
ImportError: No module named 'typing'

With this change the tests pass. (My python3 is v3.4.3.)

[refi64]

@gnprice

PYTHONPATH=`pwd`/lib-typing/3.2:`pwd` python3 tests.py

[gnprice]

@kirbyfan64 thanks, that works!

I'd love to adjust things so that the README gives instructions that will work totally smoothly. That particular command line, with PYTHONPATH, looks kind of messy and ideally I'd like to find something cleaner than that.

Looking at the Travis build instructions (in .travis.yml), it looks like another solution is to do python3 setup.py install before attempting the tests. So we could add a line to the running-tests section of the README saying to do that.

@o11c , @JukkaL , is that how you'd run tests in a fresh environment, or would you recommend something else?

[o11c]

@gnprice Everything about running the tests is about to change in #721 anyway.

[JukkaL]

We can probably wait until we have the new test driver in. Alternatively, maybe we should tweak sys.path in tests.py to include lib-typing/3.2? This way it would be less likely that people would accidentally use an incompatible version of typing.

@o11c, does the new test driver set up the environment correctly so that there is no need to tweak PYTHONPATH or install anything (other than test-requirements.txt)?

[o11c]

Yes, since tests.py no longer exists, travis.py contains the *PATH-setting logic that used to be in travis.sh. It even uses an if False branch to so that code can be typechecked before the typing module is actually importable.

[o11c]

It actually sets it to lib-typing/3.5:lib-typing/3.4:...:lib-typing/3.0 but stripping out directories that don't exist (so that the newest existing version would be used, though GvR's plan (at least for stubs) is to instead use if sys.version checks inside the module instead), and even has logic for 2.7 though that doesn't currently do anything, and probably won't be used with how I now intend to fix #732 and there are likely to be other changes with #884 and #887

[JukkaL]

Now we have a new test runner written by @o11c (runtests.py, renamed from travis.py) that can set up the path correctly for typing. Not sure what it does with Python 3.5 (haven't tried it yet) but I think that we can close this PR.

@gnprice Let me know if you still think that this is relevant. The longer-term goal would to migrate mypy to use typing installed using pip, probably.

[gnprice]

The instructions in the README WFM now out of the box. Thanks!