tests/test-simplekeyvaluefile.py

wrapfunction: use functools.partial if possible

Every `extensions.bind` call inserts a frame in traceback:

   ... in closure
     return func(*(args + a), **kw)

which makes traceback noisy.

The Python stdlib has a `functools.partial` which is backed by C code and
does not pollute traceback. However it does not support instancemethod and
sets `args` attribute which could be problematic for alias handling.

This patch makes `wrapfunction` use `functools.partial` if we are wrapping a
function directly exported by a module (so it's impossible to be a class or
instance method), and special handles `wrapfunction` results so alias
handling code could handle `args` just fine.

As an example, `hg rebase -s . -d . --traceback` got 6 lines removed in my
setup:

   File "hg/mercurial/dispatch.py", line 898, in _dispatch
     cmdpats, cmdoptions)
  -File "hg/mercurial/extensions.py", line 333, in closure
  -  return func(*(args + a), **kw)
   File "hg/hgext/journal.py", line 84, in runcommand
     return orig(lui, repo, cmd, fullargs, *args)
  -File "hg/mercurial/extensions.py", line 333, in closure
  -  return func(*(args + a), **kw)
   File "fb-hgext/hgext3rd/fbamend/hiddenoverride.py", line 119, in runcommand
     result = orig(lui, repo, cmd, fullargs, *args)
   File "hg/mercurial/dispatch.py", line 660, in runcommand
     ret = _runcommand(ui, options, cmd, d)
  -File "hg/mercurial/extensions.py", line 333, in closure
  -  return func(*(args + a), **kw)
   File "hg/hgext/pager.py", line 69, in pagecmd
     return orig(ui, options, cmd, cmdfunc)
   ....

Differential Revision: https://phab.mercurial-scm.org/D632

from __future__ import absolute_import

import unittest
import silenttestrunner

from mercurial import (
    error,
    scmutil,
)

class mockfile(object):
    def __init__(self, name, fs):
        self.name = name
        self.fs = fs

    def __enter__(self):
        return self

    def __exit__(self, *args, **kwargs):
        pass

    def write(self, text):
        self.fs.contents[self.name] = text

    def read(self):
        return self.fs.contents[self.name]

class mockvfs(object):
    def __init__(self):
        self.contents = {}

    def read(self, path):
        return mockfile(path, self).read()

    def readlines(self, path):
        # lines need to contain the trailing '\n' to mock the real readlines
        return [l for l in mockfile(path, self).read().splitlines(True)]

    def __call__(self, path, mode, atomictemp):
        return mockfile(path, self)

class testsimplekeyvaluefile(unittest.TestCase):
    def setUp(self):
        self.vfs = mockvfs()

    def testbasicwritingiandreading(self):
        dw = {'key1': 'value1', 'Key2': 'value2'}
        scmutil.simplekeyvaluefile(self.vfs, 'kvfile').write(dw)
        self.assertEqual(sorted(self.vfs.read('kvfile').split('\n')),
                         ['', 'Key2=value2', 'key1=value1'])
        dr = scmutil.simplekeyvaluefile(self.vfs, 'kvfile').read()
        self.assertEqual(dr, dw)

    def testinvalidkeys(self):
        d = {'0key1': 'value1', 'Key2': 'value2'}
        with self.assertRaisesRegexp(error.ProgrammingError,
                                     'keys must start with a letter.*'):
            scmutil.simplekeyvaluefile(self.vfs, 'kvfile').write(d)

        d = {'key1@': 'value1', 'Key2': 'value2'}
        with self.assertRaisesRegexp(error.ProgrammingError, 'invalid key.*'):
            scmutil.simplekeyvaluefile(self.vfs, 'kvfile').write(d)

    def testinvalidvalues(self):
        d = {'key1': 'value1', 'Key2': 'value2\n'}
        with self.assertRaisesRegexp(error.ProgrammingError,  'invalid val.*'):
            scmutil.simplekeyvaluefile(self.vfs, 'kvfile').write(d)

    def testcorruptedfile(self):
        self.vfs.contents['badfile'] = 'ababagalamaga\n'
        with self.assertRaisesRegexp(error.CorruptedState,
                                     'dictionary.*element.*'):
            scmutil.simplekeyvaluefile(self.vfs, 'badfile').read()

    def testfirstline(self):
        dw = {'key1': 'value1'}
        scmutil.simplekeyvaluefile(self.vfs, 'fl').write(dw, firstline='1.0')
        self.assertEqual(self.vfs.read('fl'), '1.0\nkey1=value1\n')
        dr = scmutil.simplekeyvaluefile(self.vfs, 'fl')\
                    .read(firstlinenonkeyval=True)
        self.assertEqual(dr, {'__firstline': '1.0', 'key1': 'value1'})

if __name__ == "__main__":
    silenttestrunner.main(__name__)