layouts: fix crash when importing hgsubversion itself (issue #402) Mercurial extensions are a bit weird: they aren't normally in sys.path, so you can't assume that "import hgsubversion" works. Luckily, Mercurial sneaks a little treat into sys.modules so that "import hgext_hgsubversion" does work. In fact, to get things working *as a Mercurial extension*, all that's needed is that trivial change to two import lines, in layouts/detect.py and layouts/standard.py. Unfortunately, hgsubversion is also imported as a Python module, in its own test suite. In that context, there is no "hgext_" trick -- unless we do it in ourselves, which I've done in TestBase.setUp(). That would work fine ... except that test_util imports from hgsubversion, which ends up importing hgsubversion.layouts.{detect,standard}, which want the "hgext_" trick to work. But it hasn't been done yet when we're still importing; it doesn't happen until setUp() runs. So make those two imports happen late, in the functions that need them. Incidentally, this is only necessary to support Mercurial <= 2.7. Mercurial got a bit smarter in 2.8: http://selenic.com/repo/hg/rev/621a26eb3a99

import os, sys, unittest

_rootdir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
sys.path.insert(0, _rootdir)

from hgsubversion import editor

class TestHelpers(unittest.TestCase):
    def test_filestore(self):
        fs = editor.FileStore(2)
        fs.setfile('a', 'a')
        fs.setfile('b', 'b')
        self.assertEqual('a', fs._data.get('a'))
        self.assertEqual('b', fs._data.get('b'))

        fs.delfile('b')
        self.assertRaises(IOError, lambda: fs.getfile('b'))
        fs.setfile('bb', 'bb')
        self.assertTrue('bb' in fs._files)
        self.assertTrue('bb' not in fs._data)
        self.assertEqual('bb', fs.getfile('bb'))

        fs.delfile('bb')
        self.assertTrue('bb' not in fs._files)
        self.assertEqual([], os.listdir(fs._tempdir))
        self.assertRaises(IOError, lambda: fs.getfile('bb'))

        fs.setfile('bb', 'bb')
        self.assertEqual(1, len(os.listdir(fs._tempdir)))
        fs.popfile('bb')
        self.assertEqual([], os.listdir(fs._tempdir))
        self.assertRaises(editor.EditingError, lambda: fs.getfile('bb'))