Many ReactorBuilder-style tests in twisted.internet.test do not declare their reactor requirements via requiredInterfaces

[exarkun]

ReactorBuilder.requiredInterfaces exists to allow tests which require a particular reactor interface to be skipped when an attempt is made to run those tests against a reactor which does not support that interface.

However, many of our tests (for TCP, for UNIX, for UDP, for time) do not use this feature and will still try to run against a reactor that does not provided the necessary interface.

[exarkun]

Attached is a patch that fixes the instances of this that I found. I didn't pay particularly close attention when constructing it, I just added requirements as quick as I could to get the tests to skip against my reactor that is missing most interfaces.

[exarkun]

(In [34734]) Branching to 'better-test-declarations-5521'

[exarkun]

(In [34735]) Declare that IReactorTCP is required by these test cases. Also, re-wrap docstrings to 80 columns and unify the IPv6 skip definitions.

refs #5521

[exarkun]

(In [34736]) Make all the necessary declarations for these

refs #5521

[exarkun]

(In [34737]) The same thing for IReactorTime

refs #5521

[exarkun]

(In [34739]) I feel as though I've been here before.

refs #5521

[exarkun]

(In [34742]) This is redundant now, I think

refs #5521

[exarkun]

Just what you'd expect, but overlooked before because every existing reactor already implemented all of these interfaces and no one developed new reactors very TDDly.  Build results.

[mwh]

This seems fine to me, although I have no way of verifying that it works. It certainly looks like it should :-) I don't understand the

if ipv6Skip:
    skip = ipv6Skip

construction, isn't that equivalent to plain skip = ipv6Skip. If you have a good reason for that, and you're sure the few failures in buildbot are unrelated (they certainly look unrelated to me), please merge.

[exarkun]

isn't that equivalent to plain skip = ipv6Skip

Sadly it is not. A class-level skip = None is different than not having a class-level skip attribute at all. It's terrible, and probably represents a bug or misfeature in trial to be fixed.

[exarkun]

(In [34751]) Merge better-test-declarations-5521

Author: exarkun Reviewer: mwhudson Fixes: #5521

Make sure to declare which reactor interfaces are required by various ReactorBuilder-style tests.