Move many tests from NetworkedTests and NetworkedBIOTests to a new Simple-
BackgroundTests class, using the existing ThreadedEchoServer and SIGNED_
CERTFILE infrastructure.

For tests that cause the server to crash by rejecting its certificate,
separate them into independent test methods.

Added custom root certificate to capath with the following commands:

cp Lib/test/{pycacert.pem,capath/}
# Edit copy to remove part before certificate
c_rehash -v Lib/test/capath/
c_rehash -v -old Lib/test/capath/
# Note the generated file names
cp Lib/test/capath/{pycacert.pem,b1930218.0}
mv Lib/test/capath/{pycacert.pem,ceff1710.0}

Change to pure PEM version of SIGNING_CA because PEM_cert_to_DER_cert() does
not like the extra text at the start.

Moved test_connect_ex_error() into BasicSocketTests and rewrote it to connect
to a reserved localhost port.

NetworkedTests.test_get_server_certificate_ipv6() split out because it needs
to connect to an IPv6 DNS address.

The only reference left to self-signed.pythontest.net is test_timeout_
connect_ex(), which needs a remote server to reliably time out the
connection, but does not rely on the server running SSL.

Made ThreadedEchoServer call unwrap() by default when it sees the client has
shut the connection down, so that the client can cleanly call unwrap().

See dict.__new__() and list.__new__() for comparison.  Neither of those examine or touch
args or kwds.  That work is done in the __init__() methods.

Issue #20021: use importlib.machinery to import Lib/opcode.py and not an opcode
module coming from somewhere else. makeopcodetargets.py is part of the Python
build process and it is run by an external Python program, not the built Python
program.

Patch written by Serhiy Storchaka.

Serhiy asked me to review it.

* Replace get/restore methods with a Resource class and Resource subclasses
* Create ModuleAttr, ModuleAttrList and ModuleAttrDict helper classes
* Use __subclasses__() to get resource classes instead of using an hardcoded
  list (2 shutil resources were missinged in the list!)
* Don't define MultiprocessingProcessDangling resource if the multiprocessing
  module is missing
* Nicer diff for dictionaries. Useful for the big os.environ dict
* Reorder code to group resources

tag: tip
parent: 100742:ebae81b31cf6
user: Victor Stinner <victor.stinner@gmail.com>
date: Fri Mar 25 15:03:34 2016 +0100
files: Lib/test/test_os.py
description:
test_os: Win32ErrorTests checks if file exists

Don't use os.path.exists() since it ignores *any* OSError.

Write the module name rather than <module> in the error message, if module has
no __file__ attribute (ex: package).

Issue #26610.

* Simply use "import opcode" to import the opcode module instead of tricks
  using the imp module
* Use context manager for the output file
* Move code into a new main() function
* Replace assert with a regular if to check the number of arguments
* Import modules at top level

Replace also other open(filename, "w") with open(filename, "x") to fail if a
previous test forgot to remove filename.

Changes were backported (transplated) from default to 3.5.

Use -Wd comment line option to log the ResourceWarning.

* multiprocessing: open file with closefd=False to avoid ResourceWarning
* _test_multiprocessing: open file with O_EXCL to detect bugs in tests (if a
  previous test forgot to remove TESTFN)
* test_sys_exit(): remove TESTFN after each loop iteration

Initial patch written by Serhiy Storchaka.

Use -Wd comment line option to log the ResourceWarning.

* multiprocessing: open file with closefd=False to avoid ResourceWarning
* _test_multiprocessing: open file with O_EXCL to detect bugs in tests (if a
  previous test forgot to remove TESTFN)
* test_sys_exit(): remove TESTFN after each loop iteration

Initial patch written by Serhiy Storchaka.

The import machinery now raises a different exception when it fails at Python
shutdown.

Patch by Oren Milman.

Declare the function even if thread support is disabled.

Issue #26637: The importlib module now emits an ImportError rather than a
TypeError if __import__() is tried during the Python shutdown process but
sys.path is already cleared (set to None).

Issue #21925: warnings.formatwarning() now catches exceptions when calling
linecache.getline() and tracemalloc.get_object_traceback() to be able to log
ResourceWarning emitted late during the Python shutdown process.