Tempfile management APIs for absltest.TestCase

This adds two methods to absltest.TestCase: create_tempfile() and
create_tempdir(), which allow easy and correct creation of tempfiles and
tempdirs in tests.

Creating tempfiles in tests has a variety of subtleties that these methods take
care of. Notable subtlties are platform compatibility, passing
FLAGS.test_tmpdir around correctly, passing the right arguments to mkstemp,
mkdtemp, and NamedTemporaryFile, cleanup of files, Python 2/3 API differences
in file/path functions, and ensuring file isolation between tests, among other
difficulties.

To aid debugging, cleanup of files/dirs can be controlled by the
class/instance level, by setting tempfile_cleanup, or at the
`create_temp{file,dir}()` call level by passing the `cleanup` arg.

The net effect is that tempfile setup/teardown is reduced from ~20 lines to ~3
lines, and the previously mentioned problems are taken care of by the test
framework.

New Dependencies:
  * enum34: Required under Python 2.7. Under Bazel, it is always required,
    but is not used under Python 3.

Other changes:
  * Some unrelated lines had type annotations added; this was necessary to make
    pytype happy.

PiperOrigin-RevId: 215751711

1 files changed, 1 insertions, 0 deletions

diff --git a/setup.py b/setup.py
index be45325..7d43ec8 100644
--- a/setup.py
+++ b/setup.py
@@ -52,6 +52,7 @@ setuptools.setup(
     ]),
     install_requires=[
         'six',
+        "enum34; python_version<='3.4'"
     ],
     license='Apache 2.0',
     classifiers=[