view tests/test-demandimport.py @ 51685:0eb515c7bec8

typing: add trivial type hints to the convert extension's common modules

This started as ensuring that the `encoding` and `orig_encoding` attributes has
a type other than `Any`, so pytype can catch problems where it needs to be str
for stdlib encoding and decoding.  It turns out that adding the hint in
`mercurial.encoding` is what was needed, but I picked a bunch of low hanging
fruit while here.  There's definitely more to do, and I see a problem where
`shlex.shlex` is being fed bytes instead of str, but there are not enough type
hints yet to make pytype notice.

from mercurial import demandimport

demandimport.enable()

import os
import subprocess
import sys
import types

# Don't import pycompat because it has too many side-effects.
ispy311 = (sys.version_info.major, sys.version_info.minor) >= (3, 11)

# Only run if demandimport is allowed
if subprocess.call(
    [os.environ['PYTHON'], '%s/hghave' % os.environ['TESTDIR'], 'demandimport']
):
    sys.exit(80)

# We rely on assert, which gets optimized out.
if sys.flags.optimize:
    sys.exit(80)

# The demand importer doesn't work on Python 3.5.
if sys.version_info[0:2] == (3, 5):
    sys.exit(80)

from importlib.util import _LazyModule

try:
    from importlib.util import _Module as moduletype
except ImportError:
    moduletype = types.ModuleType

if os.name != 'nt':
    try:
        import distutils.msvc9compiler

        print(
            'distutils.msvc9compiler needs to be an immediate '
            'importerror on non-windows platforms'
        )
        distutils.msvc9compiler
    except ImportError:
        pass

import re

rsub = re.sub


def f(obj):
    l = repr(obj)
    l = rsub("0x[0-9a-fA-F]+", "0x?", l)
    l = rsub("from '.*'", "from '?'", l)
    l = rsub("'<[a-z]*>'", "'<whatever>'", l)
    return l


demandimport.disable()
os.environ['HGDEMANDIMPORT'] = 'disable'
# this enable call should not actually enable demandimport!
demandimport.enable()
from mercurial import node

# We use assert instead of a unittest test case because having imports inside
# functions changes behavior of the demand importer.
assert not isinstance(node, _LazyModule)

# now enable it for real
del os.environ['HGDEMANDIMPORT']
demandimport.enable()

# Test access to special attributes through demandmod proxy
assert 'mercurial.error' not in sys.modules
from mercurial import error as errorproxy

assert isinstance(errorproxy, _LazyModule)
assert f(errorproxy) == "<module 'mercurial.error' from '?'>", f(errorproxy)

doc = ' '.join(errorproxy.__doc__.split()[:3])
assert doc == 'Mercurial exceptions. This', doc
assert errorproxy.__name__ == 'mercurial.error', errorproxy.__name__

# __name__ must be accessible via __dict__ so the relative imports can be
# resolved
name = errorproxy.__dict__['__name__']
assert name == 'mercurial.error', name

assert not isinstance(errorproxy, _LazyModule)
assert f(errorproxy) == "<module 'mercurial.error' from '?'>", f(errorproxy)

import os

assert not isinstance(os, _LazyModule)
if ispy311:
    assert f(os) == "<module 'os' (frozen)>", f(os)
else:
    assert f(os) == "<module 'os' from '?'>", f(os)

assert f(os.system) == '<built-in function system>', f(os.system)
if ispy311:
    assert f(os) == "<module 'os' (frozen)>", f(os)
else:
    assert f(os) == "<module 'os' from '?'>", f(os)

assert 'mercurial.utils.procutil' not in sys.modules
from mercurial.utils import procutil

assert isinstance(procutil, _LazyModule)
assert f(procutil) == "<module 'mercurial.utils.procutil' from '?'>", f(
    procutil
)

assert f(procutil.system) == '<function system at 0x?>', f(procutil.system)
assert procutil.__class__ == moduletype, procutil.__class__
assert f(procutil) == "<module 'mercurial.utils.procutil' from '?'>", f(
    procutil
)
assert f(procutil.system) == '<function system at 0x?>', f(procutil.system)

assert 'mercurial.hgweb' not in sys.modules
from mercurial import hgweb

assert isinstance(hgweb, _LazyModule)
assert f(hgweb) == "<module 'mercurial.hgweb' from '?'>", f(hgweb)
assert isinstance(hgweb.hgweb_mod, _LazyModule)
assert f(hgweb.hgweb_mod) == "<module 'mercurial.hgweb.hgweb_mod' from '?'>", f(
    hgweb.hgweb_mod
)

assert f(hgweb) == "<module 'mercurial.hgweb' from '?'>", f(hgweb)

import re as fred

assert not isinstance(fred, _LazyModule)
assert f(fred) == "<module 're' from '?'>"

import re as remod

assert not isinstance(remod, _LazyModule)
assert f(remod) == "<module 're' from '?'>"

import sys as re

assert not isinstance(re, _LazyModule)
assert f(re) == "<module 'sys' (built-in)>"

assert not isinstance(fred, _LazyModule)
assert f(fred) == "<module 're' from '?'>", f(fred)

assert f(fred.sub) == '<function sub at 0x?>', f(fred.sub)

assert not isinstance(fred, _LazyModule)
assert f(fred) == "<module 're' from '?'>", f(fred)

remod.escape  # use remod
assert f(remod) == "<module 're' from '?'>", f(remod)

assert not isinstance(re, _LazyModule)
assert f(re) == "<module 'sys' (built-in)>"
assert f(type(re.stderr)) == "<class '_io.TextIOWrapper'>", f(type(re.stderr))
assert f(re) == "<module 'sys' (built-in)>"

assert 'telnetlib' not in sys.modules
import telnetlib

assert isinstance(telnetlib, _LazyModule)
assert f(telnetlib) == "<module 'telnetlib' from '?'>"

try:
    from telnetlib import unknownattr

    assert False, (
        'no demandmod should be created for attribute of non-package '
        'module:\ntelnetlib.unknownattr = %s' % f(unknownattr)
    )
except ImportError as inst:
    assert rsub(r"'", '', str(inst)).startswith(
        'cannot import name unknownattr'
    )

# Unlike the import statement, __import__() function should not raise
# ImportError even if fromlist has an unknown item
# (see Python/import.c:import_module_level() and ensure_fromlist())
assert 'ftplib' not in sys.modules
zipfileimp = __import__('ftplib', globals(), locals(), ['unknownattr'])
assert f(zipfileimp) == "<module 'ftplib' from '?'>", f(zipfileimp)
assert not hasattr(zipfileimp, 'unknownattr')


# test deactivation for issue6725
del sys.modules['telnetlib']
with demandimport.deactivated():
    import telnetlib
assert telnetlib.__loader__ == telnetlib.__spec__.loader
assert telnetlib.__loader__.get_resource_reader