Add support for 3.8

[naphta]

Just a nice quick change hopefully. I've ran tox and the tests passed but really I'm just making sure when used with 3.8 it no longer pulls in the version of mypy which depends on typed_ast as that's been removed in 3.8.

I'm not very familiar with tox so correct me if I've made an erroneous change to the tox.ini (I ran tox -e py38 inside a 3.8-dev interpreter)

[dmtucker]

Thanks! 👍

Mind adding "3.8-dev" to .travis.yml too?

https://github.com/dbader/pytest-mypy/blob/b5c7f70895831ccadf48e3a84918952afc6f0795/.travis.yml#L6-L11

Also, we should probably add a new classifier to setup.py:

https://github.com/dbader/pytest-mypy/blob/b5c7f70895831ccadf48e3a84918952afc6f0795/setup.py#L45-L49

[naphta]

I've put a few of the suggested changes in (and looking at the ongoing travis build) I can't see any reason why it wouldn't pass.

I did add in support for 0.720 too.

[neozenith]

@naphta For that failing job in Travis:

The job exceeded the maximum time limit for jobs, and has been terminated.

It think the test matrix for py36 is too big now. May have to partition the matrix by python and pytest version or some other means.

[naphta]

@naphta For that failing job in Travis:

The job exceeded the maximum time limit for jobs, and has been terminated.

It think the test matrix for py36 is too big now. May have to partition the matrix by python and pytest version or some other means.

I'm not hugely familiar with Travis so I'm just wondering if you can give me any guidance for doing so?

[dmtucker]

@naphta I suspect it's because of the 0.720 addition. Maybe we should add that in a separate PR.

[neozenith]

Happy to chase up adding 0.720 support and addressing the travis yml in issue #46 if you want to remove it from this PR.

[naphta]

Happy to chase up adding 0.720 support and addressing the travis yml in issue #46 if you want to remove it from this PR.

All done.

[naphta]

Righteo, looking at the build now the errors you can see against 3.8 are what I needed to bump the version past 0.710 to solve. I'm not sure if there were other changes made to support 3.8 which fell outside of that pull request I mentioned earlier. I'm happy to bump the version up again but I'll have a look for any changes made between those releases which might be causing it.

I know there's an open issue to put in a version matrix in the documentation to make this a little bit clearer so speaking to whomever opened that issue might give me the answer.

[naphta]

Righteo, looking at the build now the errors you can see against 3.8 are what I needed to bump the version past 0.710 to solve. I'm not sure if there were other changes made to support 3.8 which fell outside of that pull request I mentioned earlier. I'm happy to bump the version up again but I'll have a look for any changes made between those releases which might be causing it.

I know there's an open issue to put in a version matrix in the documentation to make this a little bit clearer so speaking to whomever opened that issue might give me the answer.

I'm still struggling to find wind of what makes the versions different but I did track down python/mypy#7001 which suggests a release after the 16th of June would work, which sure enough v0.710 is just that. I did do a comparison of the two changesets and nothing specifically jumped out at me but I can't say I'm very familiar with their source code.

I think for now since 3.8 is a prerelease we can revisit the proper supported version once it drops for real if there's a problem.

[naphta]

Any reason not to merge now?

[dmtucker]

I think this is why 0.710 was needed: python/mypy#6937
In other words, mypy 0.70x itself works with Python 3.8, but a bug in its packaging requires a version of typed-ast that does not (< 1.4.0).

python/typed_ast#124