tests/test-demandimport.py

interfaces: convert the zope `Attribute` attrs to regular fields

At this point, we should have a useful protocol class.

The file syntax requires the type to be supplied for any fields that are
declared, but we'll leave the complex ones partially unspecified for now, for
simplicity.  (Also, the things documented as `Callable` are really as future
type annotating worked showed- roll with it for now, but they're marked as TODO
for fixing later.)  All of the fields and all of the attrs will need type
annotations, or the type rules say they are considered to be `Any`.  That can be
done in a separate pass, possibly applying the `dirstate.pyi` file generated
from the concrete class.

The first cut of this turned the `interfaceutil.Attribute` fields into plain
fields, and thus the types on them.  PyCharm flagged a few things as having
incompatible signatures when the concrete dirstate class subclassed this, when
the concrete class has them declared as `@property`.  So they've been changed to
`@property` here in those cases.  The remaining fields that are decorated in the
concrete class have comments noting the differences.  We'll see if they need to
be changed going forward, but leave them for now.  We'll be in trouble if the
`@util.propertycache` is needed, because we can't import that module here at
runtime, due to circular imports.

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

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