tests/test-doctest.py

internals: document CBOR utilization

I spoke with some people at Mozilla about CBOR and they advised me
that we should be careful about the subset of CBOR we use in order
to mitigate security, performance, and compatibility concerns.

This commit establishes a document that attempts to formalize our
use of CBOR.

Its main limitations are on what types are allowed. It explicitly
enumerates which types are supported. Notable missing features
include:

* Indefinite-length arrays and maps
* Text strings (bytes all the way)
* Floats
* Date/time types
* Big integers
* Use of indefinite-length byte strings for map keys, values in
  containers.

If we have a need for any of these, we can have a discussion about
them when the time comes.

Differential Revision: https://phab.mercurial-scm.org/D4412

# this is hack to make sure no escape characters are inserted into the output

from __future__ import absolute_import

import doctest
import os
import re
import sys

ispy3 = (sys.version_info[0] >= 3)

if 'TERM' in os.environ:
    del os.environ['TERM']

class py3docchecker(doctest.OutputChecker):
    def check_output(self, want, got, optionflags):
        want2 = re.sub(r'''\bu(['"])(.*?)\1''', r'\1\2\1', want)  # py2: u''
        got2 = re.sub(r'''\bb(['"])(.*?)\1''', r'\1\2\1', got)  # py3: b''
        # py3: <exc.name>: b'<msg>' -> <name>: <msg>
        #      <exc.name>: <others> -> <name>: <others>
        got2 = re.sub(r'''^mercurial\.\w+\.(\w+): (['"])(.*?)\2''', r'\1: \3',
                      got2, re.MULTILINE)
        got2 = re.sub(r'^mercurial\.\w+\.(\w+): ', r'\1: ', got2, re.MULTILINE)
        return any(doctest.OutputChecker.check_output(self, w, g, optionflags)
                   for w, g in [(want, got), (want2, got2)])

def testmod(name, optionflags=0, testtarget=None):
    __import__(name)
    mod = sys.modules[name]
    if testtarget is not None:
        mod = getattr(mod, testtarget)

    # minimal copy of doctest.testmod()
    finder = doctest.DocTestFinder()
    checker = None
    if ispy3:
        checker = py3docchecker()
    runner = doctest.DocTestRunner(checker=checker, optionflags=optionflags)
    for test in finder.find(mod, name):
        runner.run(test)
    runner.summarize()

testmod('mercurial.changegroup')
testmod('mercurial.changelog')
testmod('mercurial.cmdutil')
testmod('mercurial.color')
testmod('mercurial.config')
testmod('mercurial.context')
testmod('mercurial.dagparser', optionflags=doctest.NORMALIZE_WHITESPACE)
testmod('mercurial.dispatch')
testmod('mercurial.encoding')
testmod('mercurial.fancyopts')
testmod('mercurial.formatter')
testmod('mercurial.hg')
testmod('mercurial.hgweb.hgwebdir_mod')
testmod('mercurial.match')
testmod('mercurial.mdiff')
testmod('mercurial.minirst')
testmod('mercurial.patch')
testmod('mercurial.pathutil')
testmod('mercurial.parser')
testmod('mercurial.pycompat')
testmod('mercurial.revlog')
testmod('mercurial.revsetlang')
testmod('mercurial.smartset')
testmod('mercurial.store')
testmod('mercurial.subrepo')
testmod('mercurial.templatefilters')
testmod('mercurial.templater')
testmod('mercurial.ui')
testmod('mercurial.url')
testmod('mercurial.util')
testmod('mercurial.util', testtarget='platform')
testmod('mercurial.utils.stringutil')
testmod('hgext.convert.convcmd')
testmod('hgext.convert.cvsps')
testmod('hgext.convert.filemap')
testmod('hgext.convert.p4')
testmod('hgext.convert.subversion')
testmod('hgext.fix')
testmod('hgext.mq')
# Helper scripts in tests/ that have doctests:
testmod('drawdag')