tests: fix test-demandimport.py on Python 3.9

Starting with Python 3.9, importing importlib.resources (indirectly) imports
the zipfile module. Therefore, the module is not suitable for the test.
Instead, we can use the ftplib module, which is very unlikely to be imported
during the test run.

tests/test-demandimport.py

@@ -1,238 +1,238 b''
 from __future__ import absolute_import, print_function
 
 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.
 ispy3 = sys.version_info[0] >= 3
 
 # Only run if demandimport is allowed
 if subprocess.call(
     ['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)
 
 if ispy3:
     from importlib.util import _LazyModule
 
     try:
         from importlib.util import _Module as moduletype
     except ImportError:
         moduletype = types.ModuleType
 else:
     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.
 if ispy3:
     assert not isinstance(node, _LazyModule)
 else:
     assert f(node) == "<module 'mercurial.node' from '?'>", f(node)
 
 # 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
 
 if ispy3:
     # unsure why this isn't lazy.
     assert not isinstance(f, _LazyModule)
     assert f(errorproxy) == "<module 'mercurial.error' from '?'>", f(errorproxy)
 else:
     assert f(errorproxy) == "<unloaded module 'error'>", 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
 
 if ispy3:
     assert not isinstance(errorproxy, _LazyModule)
     assert f(errorproxy) == "<module 'mercurial.error' from '?'>", f(errorproxy)
 else:
     assert f(errorproxy) == "<proxied module 'error'>", f(errorproxy)
 
 import os
 
 if ispy3:
     assert not isinstance(os, _LazyModule)
     assert f(os) == "<module 'os' from '?'>", f(os)
 else:
     assert f(os) == "<unloaded module 'os'>", f(os)
 
 assert f(os.system) == '<built-in function system>', f(os.system)
 assert f(os) == "<module 'os' from '?'>", f(os)
 
 assert 'mercurial.utils.procutil' not in sys.modules
 from mercurial.utils import procutil
 
 if ispy3:
     assert isinstance(procutil, _LazyModule)
     assert f(procutil) == "<module 'mercurial.utils.procutil' from '?'>", f(
         procutil
     )
 else:
     assert f(procutil) == "<unloaded module 'procutil'>", 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
 
 if ispy3:
     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)
 else:
     assert f(hgweb) == "<unloaded module 'hgweb'>", f(hgweb)
     assert f(hgweb.hgweb_mod) == "<unloaded module 'hgweb_mod'>", f(
         hgweb.hgweb_mod
     )
 
 assert f(hgweb) == "<module 'mercurial.hgweb' from '?'>", f(hgweb)
 
 import re as fred
 
 if ispy3:
     assert not isinstance(fred, _LazyModule)
     assert f(fred) == "<module 're' from '?'>"
 else:
     assert f(fred) == "<unloaded module 're'>", f(fred)
 
 import re as remod
 
 if ispy3:
     assert not isinstance(remod, _LazyModule)
     assert f(remod) == "<module 're' from '?'>"
 else:
     assert f(remod) == "<unloaded module 're'>", f(remod)
 
 import sys as re
 
 if ispy3:
     assert not isinstance(re, _LazyModule)
     assert f(re) == "<module 'sys' (built-in)>"
 else:
     assert f(re) == "<unloaded module 'sys'>", f(re)
 
 if ispy3:
     assert not isinstance(fred, _LazyModule)
     assert f(fred) == "<module 're' from '?'>", f(fred)
 else:
     assert f(fred) == "<unloaded module 're'>", f(fred)
 
 assert f(fred.sub) == '<function sub at 0x?>', f(fred.sub)
 
 if ispy3:
     assert not isinstance(fred, _LazyModule)
     assert f(fred) == "<module 're' from '?'>", f(fred)
 else:
     assert f(fred) == "<proxied module 're'>", f(fred)
 
 remod.escape  # use remod
 assert f(remod) == "<module 're' from '?'>", f(remod)
 
 if ispy3:
     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)>"
 else:
     assert f(re) == "<unloaded module 'sys'>", f(re)
     assert f(re.stderr) == "<open file '<whatever>', mode 'w' at 0x?>", f(
         re.stderr
     )
     assert f(re) == "<proxied module 'sys'>", f(re)
 
 assert 'telnetlib' not in sys.modules
 import telnetlib
 
 if ispy3:
     assert isinstance(telnetlib, _LazyModule)
     assert f(telnetlib) == "<module 'telnetlib' from '?'>"
 else:
     assert f(telnetlib) == "<unloaded module 'telnetlib'>", f(telnetlib)
 
 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'
     )
 
 from mercurial import util
 
 # 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 'zipfile' not in sys.modules
-zipfileimp = __import__('zipfile', globals(), locals(), ['unknownattr'])
-assert f(zipfileimp) == "<module 'zipfile' from '?'>", f(zipfileimp)
+assert 'ftplib' not in sys.modules
+zipfileimp = __import__('ftplib', globals(), locals(), ['unknownattr'])
+assert f(zipfileimp) == "<module 'ftplib' from '?'>", f(zipfileimp)
 assert not util.safehasattr(zipfileimp, 'unknownattr')