Mercurial > hg
view tests/test-ctxmanager.py @ 29759:e584c6235500
py3: conditionalize the raise statement
raise E,V,T is not acceptable in Python 3, thats is conditionalized.
Moreover this will result in syntax error so we have to use exec() to
execute this. Related PEP- https://www.python.org/dev/peps/pep-3109/#id14
My implementation is motivated from the six implementation except they are
defining a new function exec_() to prevent adding an extra frame AFAIK :)
https://bitbucket.org/gutworth/six/src/ca4580a5a648/six.py#six.py-680
author | Pulkit Goyal <7895pulkit@gmail.com> |
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date | Mon, 08 Aug 2016 23:51:11 +0530 |
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__)