Mercurial > hg
view tests/test-ctxmanager.py @ 31432:6e1c79578e5c
mq: explicitly tests for None
Changeset fd3d8eb7f545 removed the mutable default value, but did not explicitly
tested for None. Such implicit testing can introduce semantic and performance
issue. We move to an explicit testing for None as recommended by PEP8:
https://www.python.org/dev/peps/pep-0008/#programming-recommendations
author | Pierre-Yves David <pierre-yves.david@ens-lyon.org> |
---|---|
date | Wed, 15 Mar 2017 15:05:54 -0700 |
parents | 441491aba8c3 |
children | 68c43a416585 |
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from __future__ import absolute_import import silenttestrunner import unittest from mercurial import util class contextmanager(object): def __init__(self, name, trace): self.name = name self.entered = False self.exited = False self.trace = trace def __enter__(self): self.entered = True self.trace(('enter', self.name)) return self def __exit__(self, exc_type, exc_val, exc_tb): self.exited = exc_type, exc_val, exc_tb self.trace(('exit', self.name)) def __repr__(self): return '<ctx %r>' % self.name class ctxerror(Exception): pass class raise_on_enter(contextmanager): def __enter__(self): self.trace(('raise', self.name)) raise ctxerror(self.name) class raise_on_exit(contextmanager): def __exit__(self, exc_type, exc_val, exc_tb): self.trace(('raise', self.name)) raise ctxerror(self.name) def ctxmgr(name, trace): return lambda: contextmanager(name, trace) class test_ctxmanager(unittest.TestCase): def test_basics(self): trace = [] addtrace = trace.append with util.ctxmanager(ctxmgr('a', addtrace), ctxmgr('b', addtrace)) as c: a, b = c.enter() c.atexit(addtrace, ('atexit', 'x')) c.atexit(addtrace, ('atexit', 'y')) self.assertEqual(trace, [('enter', 'a'), ('enter', 'b'), ('atexit', 'y'), ('atexit', 'x'), ('exit', 'b'), ('exit', 'a')]) def test_raise_on_enter(self): trace = [] addtrace = trace.append def go(): with util.ctxmanager(ctxmgr('a', addtrace), lambda: raise_on_enter('b', addtrace)) as c: c.enter() addtrace('unreachable') self.assertRaises(ctxerror, go) self.assertEqual(trace, [('enter', 'a'), ('raise', 'b'), ('exit', 'a')]) def test_raise_on_exit(self): trace = [] addtrace = trace.append def go(): with util.ctxmanager(ctxmgr('a', addtrace), lambda: raise_on_exit('b', addtrace)) as c: c.enter() addtrace('running') self.assertRaises(ctxerror, go) self.assertEqual(trace, [('enter', 'a'), ('enter', 'b'), 'running', ('raise', 'b'), ('exit', 'a')]) if __name__ == '__main__': silenttestrunner.main(__name__)