view tests/test-atomictempfile.py @ 19933:621a26eb3a99

demandimport: allow extensions to import own modules by absolute name

Before this patch, python modules of each extensions can't import
another one in own extension by absolute name, because root modules of
each extensions are loaded with "hgext_" prefix.

For example, "import extroot.bar" in "extroot/foo.py" of "extroot"
extension fails, even though "import bar" in it succeeds.

Installing extensions into site-packages of python library path can
avoid this problem, but this solution is not reasonable in some cases:
using binary package of Mercurial on Windows, for example.

This patch retries to import with "hgext_" prefix after ImportError,
if the module in the extension may try to import another one in own
extension.

This patch doesn't change some "_import()"/"_origimport()" invocations
below, because ordinary extensions shouldn't cause such invocations.

    - invocation of "_import()" when root module imports sub-module by
      absolute path without "fromlist"

      for example, "import a.b" in "a.__init__.py".

      extensions are loaded with "hgext_" prefix, and this causes
      execution of another (= fixed by this patch) code path.

    - invocation of "_origimport()" when "level != -1" with "fromlist"

      for example, importing after "from __future__ import
      absolute_import" (level == 0), or "from . import b" or "from .a
      import b" (0 < level),

      for portability between python versions and environments,
      extensions shouldn't cause "level != -1".

import os
import glob
import unittest
import silenttestrunner

from mercurial.util import atomictempfile

class testatomictempfile(unittest.TestCase):
    def test1_simple(self):
        if os.path.exists('foo'):
            os.remove('foo')
        file = atomictempfile('foo')
        (dir, basename) = os.path.split(file._tempname)
        self.assertFalse(os.path.isfile('foo'))
        self.assertTrue(basename in glob.glob('.foo-*'))

        file.write('argh\n')
        file.close()

        self.assertTrue(os.path.isfile('foo'))
        self.assertTrue(basename not in glob.glob('.foo-*'))

    # discard() removes the temp file without making the write permanent
    def test2_discard(self):
        if os.path.exists('foo'):
            os.remove('foo')
        file = atomictempfile('foo')
        (dir, basename) = os.path.split(file._tempname)

        file.write('yo\n')
        file.discard()

        self.assertFalse(os.path.isfile('foo'))
        self.assertTrue(basename not in os.listdir('.'))

    # if a programmer screws up and passes bad args to atomictempfile, they
    # get a plain ordinary TypeError, not infinite recursion
    def test3_oops(self):
        self.assertRaises(TypeError, atomictempfile)

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