Run unit tests on Travis CI

[hugovk]

It's a good idea to use Travis CI to run the unit tests. These will run for every commit and also for every PR. It's free for open source projects.

You get a report like this: https://travis-ci.org/hugovk/demjson/builds/78413297

Right now, the Python 3 tests aren't passing, it looks like it's because of using non-Python 3 prints. So for now, I've put those in an allow_failures section. They can be removed once they pass.

TODO by the dmeranda repo owner: enable Travis for dmeranda/demjson here: https://travis-ci.org/profile/

[dmeranda]

I don't know how your tests are configured, but as for Python 3, are you sure that the 2to3 converter is being executed?

demjson already has rather thorough self-tests included, which use the Python "unittest" module. It includes several specific tests just for Python 3 operation. See the test scripts under the "test/" directory, or just run "make test". If you are using Python 3 and did not install in a normal manner (e.g., pip or using setup.py) then remember you must run the 2to3 converter on all the *.py files.

[hugovk]

I hadn't installed with python setup.py install and also hadn't called 2to3.

But now the PR does this:

 - python setup.py install
 - cd test
 - if [ ${TRAVIS_PYTHON_VERSION:0:1} == "3" ]; then 2to3 -w test_demjson.py; fi
 - PYTHONPATH=.. python test_demjson.py

And still fails on Python 3:

$ PYTHONPATH=.. python test_demjson.py
Traceback (most recent call last):
  File "test_demjson.py", line 25, in <module>
    import demjson
  File "../demjson.py", line 645
    class json_int( (1L).__class__ ):    # Have to specify base this way to satisfy 2to3
                      ^
SyntaxError: invalid syntax

https://travis-ci.org/hugovk/demjson/builds/83754575

I get the same thing locally with Python 3.4.2, after:

cd test
2to3 -w test_demjson.py 

I get:

[hugo:~/github/demjson/test] travis(+89/-91)* ± PYTHONPATH=.. python3 test_demjson.py
Traceback (most recent call last):
  File "test_demjson.py", line 25, in <module>
    import demjson
  File "../demjson.py", line 645
    class json_int( (1L).__class__ ):    # Have to specify base this way to satisfy 2to3
                      ^
SyntaxError: invalid syntax

[dmeranda]

You need to run 2to3 on all Python files. Try

2to3 -w demjson.py
cd test
2to3 -w test_demjson.py

[hugovk]

Aha, that was the problem!

All pass (except pypy3, but that's a bit of an edge case): https://travis-ci.org/hugovk/demjson/builds/83763109

[hugovk]

By the way, docs say:

If you have installed demjson with a standard PyPI package distribution mechanism; such as pip, easy_install, or just typing "python3 setup.py install"; then the 2to3 conversion will be performed automatically as part of the installation process.

https://github.com/dmeranda/demjson/blob/master/docs/PYTHON3.txt#L19-L22

But I was calling python setup.py install at one point but it didn't do 2to3.

[jayvdb]

I've approached this same problem slightly differently; see #19 .

[hugovk]

@dmeranda Any thoughts about this and #19? Thank you.