tests/test-atomictempfile.py

histedit: correct the number of added revisions in online help

In the context of help document on which this patch focuses, the
example repository, which is source of cloning, should be already
histedit-ed, and contain only 3 revisions (rev # 0 to 2). So, not 3,
but 4 revisions should be added to the destination repository of
cloning, if it contains 7 revisions (rev # 0 to 6).

This patch also adds modifier "histedit-ed" to "example repository",
to make context clear.

import os
import glob
from mercurial.util import atomictempfile

# basic usage
def test1_simple():
    if os.path.exists('foo'):
        os.remove('foo')
    file = atomictempfile('foo')
    (dir, basename) = os.path.split(file._tempname)
    assert not os.path.isfile('foo')
    assert basename in glob.glob('.foo-*')

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

    assert os.path.isfile('foo')
    assert basename not in glob.glob('.foo-*')
    print 'OK'

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

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

    assert not os.path.isfile('foo')
    assert basename not in os.listdir('.')
    print 'OK'

# if a programmer screws up and passes bad args to atomictempfile, they
# get a plain ordinary TypeError, not infinite recursion
def test3_oops():
    try:
        file = atomictempfile()
    except TypeError:
        print "OK"
    else:
        print "expected TypeError"

if __name__ == '__main__':
    test1_simple()
    test2_discard()
    test3_oops()