tests/test-atomictempfile.py

exchange: parse requirements from stream clone specification string

Stream clone bundles can only be consumed if the consumer supports the
exact format requirements that were present on the producer.

This patch adds support for encoding and verifying the format
requirements on the bundle specification string for a stream clone
bundle are supported by the local repository. If they aren't, we raise
an UnsupportedBundleSpecification, just like we do when an unknown
compression or bundle type is encountered.

The impetus for this patch is so the clone bundles manifest can
advertise stream clone bundles and so clients can filter out stream
clones with unsupported format requirements. e.g. a stream clone
produced with the not-yet-invented "revlogv2" format will be ignored by
clients that only support "revlogv1."

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__)