cpython/Lib/test/test_fileio.py

777 lines
26 KiB
Python

# Adapted from test_file.py by Daniel Stutzbach
import sys
import os
import io
import errno
import unittest
from array import array
from weakref import proxy
from functools import wraps
from test.support import (
cpython_only, swap_attr, gc_collect, is_emscripten, is_wasi,
infinite_recursion, strace_helper
)
from test.support.os_helper import (
TESTFN, TESTFN_ASCII, TESTFN_UNICODE, make_bad_fd,
)
from test.support.warnings_helper import check_warnings
from test.support.import_helper import import_module
from collections import UserList
import _io # C implementation of io
import _pyio # Python implementation of io
_strace_flags=["--trace=%file,%desc"]
class AutoFileTests:
# file tests for which a test file is automatically set up
def setUp(self):
self.f = self.FileIO(TESTFN, 'w')
def tearDown(self):
if self.f:
self.f.close()
os.remove(TESTFN)
def testWeakRefs(self):
# verify weak references
p = proxy(self.f)
p.write(bytes(range(10)))
self.assertEqual(self.f.tell(), p.tell())
self.f.close()
self.f = None
gc_collect() # For PyPy or other GCs.
self.assertRaises(ReferenceError, getattr, p, 'tell')
def testSeekTell(self):
self.f.write(bytes(range(20)))
self.assertEqual(self.f.tell(), 20)
self.f.seek(0)
self.assertEqual(self.f.tell(), 0)
self.f.seek(10)
self.assertEqual(self.f.tell(), 10)
self.f.seek(5, 1)
self.assertEqual(self.f.tell(), 15)
self.f.seek(-5, 1)
self.assertEqual(self.f.tell(), 10)
self.f.seek(-5, 2)
self.assertEqual(self.f.tell(), 15)
def testAttributes(self):
# verify expected attributes exist
f = self.f
self.assertEqual(f.mode, "wb")
self.assertEqual(f.closed, False)
# verify the attributes are readonly
for attr in 'mode', 'closed':
self.assertRaises((AttributeError, TypeError),
setattr, f, attr, 'oops')
@unittest.skipIf(is_wasi, "WASI does not expose st_blksize.")
def testBlksize(self):
# test private _blksize attribute
blksize = io.DEFAULT_BUFFER_SIZE
# try to get preferred blksize from stat.st_blksize, if available
if hasattr(os, 'fstat'):
fst = os.fstat(self.f.fileno())
blksize = getattr(fst, 'st_blksize', blksize)
self.assertEqual(self.f._blksize, blksize)
# verify readinto
def testReadintoByteArray(self):
self.f.write(bytes([1, 2, 0, 255]))
self.f.close()
ba = bytearray(b'abcdefgh')
with self.FileIO(TESTFN, 'r') as f:
n = f.readinto(ba)
self.assertEqual(ba, b'\x01\x02\x00\xffefgh')
self.assertEqual(n, 4)
def _testReadintoMemoryview(self):
self.f.write(bytes([1, 2, 0, 255]))
self.f.close()
m = memoryview(bytearray(b'abcdefgh'))
with self.FileIO(TESTFN, 'r') as f:
n = f.readinto(m)
self.assertEqual(m, b'\x01\x02\x00\xffefgh')
self.assertEqual(n, 4)
m = memoryview(bytearray(b'abcdefgh')).cast('H', shape=[2, 2])
with self.FileIO(TESTFN, 'r') as f:
n = f.readinto(m)
self.assertEqual(bytes(m), b'\x01\x02\x00\xffefgh')
self.assertEqual(n, 4)
def _testReadintoArray(self):
self.f.write(bytes([1, 2, 0, 255]))
self.f.close()
a = array('B', b'abcdefgh')
with self.FileIO(TESTFN, 'r') as f:
n = f.readinto(a)
self.assertEqual(a, array('B', [1, 2, 0, 255, 101, 102, 103, 104]))
self.assertEqual(n, 4)
a = array('b', b'abcdefgh')
with self.FileIO(TESTFN, 'r') as f:
n = f.readinto(a)
self.assertEqual(a, array('b', [1, 2, 0, -1, 101, 102, 103, 104]))
self.assertEqual(n, 4)
a = array('I', b'abcdefgh')
with self.FileIO(TESTFN, 'r') as f:
n = f.readinto(a)
self.assertEqual(a, array('I', b'\x01\x02\x00\xffefgh'))
self.assertEqual(n, 4)
def testWritelinesList(self):
l = [b'123', b'456']
self.f.writelines(l)
self.f.close()
self.f = self.FileIO(TESTFN, 'rb')
buf = self.f.read()
self.assertEqual(buf, b'123456')
def testWritelinesUserList(self):
l = UserList([b'123', b'456'])
self.f.writelines(l)
self.f.close()
self.f = self.FileIO(TESTFN, 'rb')
buf = self.f.read()
self.assertEqual(buf, b'123456')
def testWritelinesError(self):
self.assertRaises(TypeError, self.f.writelines, [1, 2, 3])
self.assertRaises(TypeError, self.f.writelines, None)
self.assertRaises(TypeError, self.f.writelines, "abc")
def test_none_args(self):
self.f.write(b"hi\nbye\nabc")
self.f.close()
self.f = self.FileIO(TESTFN, 'r')
self.assertEqual(self.f.read(None), b"hi\nbye\nabc")
self.f.seek(0)
self.assertEqual(self.f.readline(None), b"hi\n")
self.assertEqual(self.f.readlines(None), [b"bye\n", b"abc"])
def test_reject(self):
self.assertRaises(TypeError, self.f.write, "Hello!")
def testRepr(self):
self.assertEqual(repr(self.f),
"<%s.FileIO name=%r mode=%r closefd=True>" %
(self.modulename, self.f.name, self.f.mode))
del self.f.name
self.assertEqual(repr(self.f),
"<%s.FileIO fd=%r mode=%r closefd=True>" %
(self.modulename, self.f.fileno(), self.f.mode))
self.f.close()
self.assertEqual(repr(self.f),
"<%s.FileIO [closed]>" % (self.modulename,))
def test_subclass_repr(self):
class TestSubclass(self.FileIO):
pass
f = TestSubclass(TESTFN)
with f:
self.assertIn(TestSubclass.__name__, repr(f))
self.assertIn(TestSubclass.__name__, repr(f))
def testReprNoCloseFD(self):
fd = os.open(TESTFN, os.O_RDONLY)
try:
with self.FileIO(fd, 'r', closefd=False) as f:
self.assertEqual(repr(f),
"<%s.FileIO name=%r mode=%r closefd=False>" %
(self.modulename, f.name, f.mode))
finally:
os.close(fd)
@infinite_recursion(25)
def testRecursiveRepr(self):
# Issue #25455
with swap_attr(self.f, 'name', self.f):
with self.assertRaises(RuntimeError):
repr(self.f) # Should not crash
def testErrors(self):
f = self.f
self.assertFalse(f.isatty())
self.assertFalse(f.closed)
#self.assertEqual(f.name, TESTFN)
self.assertRaises(ValueError, f.read, 10) # Open for reading
f.close()
self.assertTrue(f.closed)
f = self.FileIO(TESTFN, 'r')
self.assertRaises(TypeError, f.readinto, "")
self.assertFalse(f.closed)
f.close()
self.assertTrue(f.closed)
def testMethods(self):
methods = ['fileno', 'isatty', 'seekable', 'readable', 'writable',
'read', 'readall', 'readline', 'readlines',
'tell', 'truncate', 'flush']
self.f.close()
self.assertTrue(self.f.closed)
for methodname in methods:
method = getattr(self.f, methodname)
# should raise on closed file
self.assertRaises(ValueError, method)
self.assertRaises(TypeError, self.f.readinto)
self.assertRaises(ValueError, self.f.readinto, bytearray(1))
self.assertRaises(TypeError, self.f.seek)
self.assertRaises(ValueError, self.f.seek, 0)
self.assertRaises(TypeError, self.f.write)
self.assertRaises(ValueError, self.f.write, b'')
self.assertRaises(TypeError, self.f.writelines)
self.assertRaises(ValueError, self.f.writelines, b'')
def testOpendir(self):
# Issue 3703: opening a directory should fill the errno
# Windows always returns "[Errno 13]: Permission denied
# Unix uses fstat and returns "[Errno 21]: Is a directory"
try:
self.FileIO('.', 'r')
except OSError as e:
self.assertNotEqual(e.errno, 0)
self.assertEqual(e.filename, ".")
else:
self.fail("Should have raised OSError")
@unittest.skipIf(os.name == 'nt', "test only works on a POSIX-like system")
def testOpenDirFD(self):
fd = os.open('.', os.O_RDONLY)
with self.assertRaises(OSError) as cm:
self.FileIO(fd, 'r')
os.close(fd)
self.assertEqual(cm.exception.errno, errno.EISDIR)
#A set of functions testing that we get expected behaviour if someone has
#manually closed the internal file descriptor. First, a decorator:
def ClosedFD(func):
@wraps(func)
def wrapper(self):
#forcibly close the fd before invoking the problem function
f = self.f
os.close(f.fileno())
try:
func(self, f)
finally:
try:
self.f.close()
except OSError:
pass
return wrapper
def ClosedFDRaises(func):
@wraps(func)
def wrapper(self):
#forcibly close the fd before invoking the problem function
f = self.f
os.close(f.fileno())
try:
func(self, f)
except OSError as e:
self.assertEqual(e.errno, errno.EBADF)
else:
self.fail("Should have raised OSError")
finally:
try:
self.f.close()
except OSError:
pass
return wrapper
@ClosedFDRaises
def testErrnoOnClose(self, f):
f.close()
@ClosedFDRaises
def testErrnoOnClosedWrite(self, f):
f.write(b'a')
@ClosedFDRaises
def testErrnoOnClosedSeek(self, f):
f.seek(0)
@ClosedFDRaises
def testErrnoOnClosedTell(self, f):
f.tell()
@ClosedFDRaises
def testErrnoOnClosedTruncate(self, f):
f.truncate(0)
@ClosedFD
def testErrnoOnClosedSeekable(self, f):
f.seekable()
@ClosedFD
def testErrnoOnClosedReadable(self, f):
f.readable()
@ClosedFD
def testErrnoOnClosedWritable(self, f):
f.writable()
@ClosedFD
def testErrnoOnClosedFileno(self, f):
f.fileno()
@ClosedFD
def testErrnoOnClosedIsatty(self, f):
self.assertEqual(f.isatty(), False)
def ReopenForRead(self):
try:
self.f.close()
except OSError:
pass
self.f = self.FileIO(TESTFN, 'r')
os.close(self.f.fileno())
return self.f
@ClosedFDRaises
def testErrnoOnClosedRead(self, f):
f = self.ReopenForRead()
f.read(1)
@ClosedFDRaises
def testErrnoOnClosedReadall(self, f):
f = self.ReopenForRead()
f.readall()
@ClosedFDRaises
def testErrnoOnClosedReadinto(self, f):
f = self.ReopenForRead()
a = array('b', b'x'*10)
f.readinto(a)
@strace_helper.requires_strace()
def test_syscalls_read(self):
"""Check that the set of system calls produced by the I/O stack is what
is expected for various read cases.
It's expected as bits of the I/O implementation change, this will need
to change. The goal is to catch changes that unintentionally add
additional systemcalls (ex. additional calls have been looked at in
bpo-21679 and gh-120754).
"""
self.f.write(b"Hello, World!")
self.f.close()
def check_readall(name, code, prelude="", cleanup="",
extra_checks=None):
with self.subTest(name=name):
syscalls = strace_helper.get_events(code, _strace_flags,
prelude=prelude,
cleanup=cleanup)
# The first call should be an open that returns a
# file descriptor (fd). Afer that calls may vary. Once the file
# is opened, check calls refer to it by fd as the filename
# could be removed from the filesystem, renamed, etc. See:
# Time-of-check time-of-use (TOCTOU) software bug class.
#
# There are a number of related but distinct open system calls
# so not checking precise name here.
self.assertGreater(
len(syscalls),
1,
f"Should have had at least an open call|calls={syscalls}")
fd_str = syscalls[0].returncode
# All other calls should contain the fd in their argument set.
for ev in syscalls[1:]:
self.assertIn(
fd_str,
ev.args,
f"Looking for file descriptor in arguments|ev={ev}"
)
# There are a number of related syscalls used to implement
# behaviors in a libc (ex. fstat, newfstatat, statx, open, openat).
# Allow any that use the same substring.
def count_similarname(name):
return len([ev for ev in syscalls if name in ev.syscall])
checks = [
# Should open and close the file exactly once
("open", 1),
("close", 1),
# There should no longer be an isatty call (All files being
# tested are block devices / not character devices).
('ioctl', 0),
# Should only have one fstat (bpo-21679, gh-120754)
# note: It's important this uses a fd rather than filename,
# That is validated by the `fd` check above.
# note: fstat, newfstatat, and statx have all been observed
# here in the underlying C library implementations.
("stat", 1)
]
if extra_checks:
checks += extra_checks
for call, count in checks:
self.assertEqual(
count_similarname(call),
count,
msg=f"call={call}|count={count}|syscalls={syscalls}"
)
# "open, read, close" file using different common patterns.
check_readall(
"open builtin with default options",
f"""
f = open('{TESTFN}')
f.read()
f.close()
"""
)
check_readall(
"open in binary mode",
f"""
f = open('{TESTFN}', 'rb')
f.read()
f.close()
"""
)
check_readall(
"open in text mode",
f"""
f = open('{TESTFN}', 'rt')
f.read()
f.close()
""",
# GH-122111: read_text uses BufferedIO which requires looking up
# position in file. `read_bytes` disables that buffering and avoids
# these calls which is tested the `pathlib read_bytes` case.
extra_checks=[("seek", 1)]
)
check_readall(
"pathlib read_bytes",
"p.read_bytes()",
prelude=f"""from pathlib import Path; p = Path("{TESTFN}")""",
# GH-122111: Buffering is disabled so these calls are avoided.
extra_checks=[("seek", 0)]
)
check_readall(
"pathlib read_text",
"p.read_text()",
prelude=f"""from pathlib import Path; p = Path("{TESTFN}")"""
)
# Focus on just `read()`.
calls = strace_helper.get_syscalls(
prelude=f"f = open('{TESTFN}')",
code="f.read()",
cleanup="f.close()",
strace_flags=_strace_flags
)
# One to read all the bytes
# One to read the EOF and get a size 0 return.
self.assertEqual(calls.count("read"), 2)
class CAutoFileTests(AutoFileTests, unittest.TestCase):
FileIO = _io.FileIO
modulename = '_io'
class PyAutoFileTests(AutoFileTests, unittest.TestCase):
FileIO = _pyio.FileIO
modulename = '_pyio'
class OtherFileTests:
def testAbles(self):
try:
f = self.FileIO(TESTFN, "w")
self.assertEqual(f.readable(), False)
self.assertEqual(f.writable(), True)
self.assertEqual(f.seekable(), True)
f.close()
f = self.FileIO(TESTFN, "r")
self.assertEqual(f.readable(), True)
self.assertEqual(f.writable(), False)
self.assertEqual(f.seekable(), True)
f.close()
f = self.FileIO(TESTFN, "a+")
self.assertEqual(f.readable(), True)
self.assertEqual(f.writable(), True)
self.assertEqual(f.seekable(), True)
self.assertEqual(f.isatty(), False)
f.close()
if sys.platform != "win32" and not is_emscripten:
try:
f = self.FileIO("/dev/tty", "a")
except OSError:
# When run in a cron job there just aren't any
# ttys, so skip the test. This also handles other
# OS'es that don't support /dev/tty.
pass
else:
self.assertEqual(f.readable(), False)
self.assertEqual(f.writable(), True)
if sys.platform != "darwin" and \
'bsd' not in sys.platform and \
not sys.platform.startswith(('sunos', 'aix')):
# Somehow /dev/tty appears seekable on some BSDs
self.assertEqual(f.seekable(), False)
self.assertEqual(f.isatty(), True)
f.close()
finally:
os.unlink(TESTFN)
def testInvalidModeStrings(self):
# check invalid mode strings
for mode in ("", "aU", "wU+", "rw", "rt"):
try:
f = self.FileIO(TESTFN, mode)
except ValueError:
pass
else:
f.close()
self.fail('%r is an invalid file mode' % mode)
def testModeStrings(self):
# test that the mode attribute is correct for various mode strings
# given as init args
try:
for modes in [('w', 'wb'), ('wb', 'wb'), ('wb+', 'rb+'),
('w+b', 'rb+'), ('a', 'ab'), ('ab', 'ab'),
('ab+', 'ab+'), ('a+b', 'ab+'), ('r', 'rb'),
('rb', 'rb'), ('rb+', 'rb+'), ('r+b', 'rb+')]:
# read modes are last so that TESTFN will exist first
with self.FileIO(TESTFN, modes[0]) as f:
self.assertEqual(f.mode, modes[1])
finally:
if os.path.exists(TESTFN):
os.unlink(TESTFN)
def testUnicodeOpen(self):
# verify repr works for unicode too
f = self.FileIO(str(TESTFN), "w")
f.close()
os.unlink(TESTFN)
def testBytesOpen(self):
# Opening a bytes filename
fn = TESTFN_ASCII.encode("ascii")
f = self.FileIO(fn, "w")
try:
f.write(b"abc")
f.close()
with open(TESTFN_ASCII, "rb") as f:
self.assertEqual(f.read(), b"abc")
finally:
os.unlink(TESTFN_ASCII)
@unittest.skipIf(sys.getfilesystemencoding() != 'utf-8',
"test only works for utf-8 filesystems")
def testUtf8BytesOpen(self):
# Opening a UTF-8 bytes filename
try:
fn = TESTFN_UNICODE.encode("utf-8")
except UnicodeEncodeError:
self.skipTest('could not encode %r to utf-8' % TESTFN_UNICODE)
f = self.FileIO(fn, "w")
try:
f.write(b"abc")
f.close()
with open(TESTFN_UNICODE, "rb") as f:
self.assertEqual(f.read(), b"abc")
finally:
os.unlink(TESTFN_UNICODE)
def testConstructorHandlesNULChars(self):
fn_with_NUL = 'foo\0bar'
self.assertRaises(ValueError, self.FileIO, fn_with_NUL, 'w')
self.assertRaises(ValueError, self.FileIO, bytes(fn_with_NUL, 'ascii'), 'w')
def testInvalidFd(self):
self.assertRaises(ValueError, self.FileIO, -10)
self.assertRaises(OSError, self.FileIO, make_bad_fd())
if sys.platform == 'win32':
import msvcrt
self.assertRaises(OSError, msvcrt.get_osfhandle, make_bad_fd())
def testBooleanFd(self):
for fd in False, True:
with self.assertWarnsRegex(RuntimeWarning,
'bool is used as a file descriptor') as cm:
f = self.FileIO(fd, closefd=False)
f.close()
self.assertEqual(cm.filename, __file__)
def testBadModeArgument(self):
# verify that we get a sensible error message for bad mode argument
bad_mode = "qwerty"
try:
f = self.FileIO(TESTFN, bad_mode)
except ValueError as msg:
if msg.args[0] != 0:
s = str(msg)
if TESTFN in s or bad_mode not in s:
self.fail("bad error message for invalid mode: %s" % s)
# if msg.args[0] == 0, we're probably on Windows where there may be
# no obvious way to discover why open() failed.
else:
f.close()
self.fail("no error for invalid mode: %s" % bad_mode)
def testTruncate(self):
f = self.FileIO(TESTFN, 'w')
f.write(bytes(bytearray(range(10))))
self.assertEqual(f.tell(), 10)
f.truncate(5)
self.assertEqual(f.tell(), 10)
self.assertEqual(f.seek(0, io.SEEK_END), 5)
f.truncate(15)
self.assertEqual(f.tell(), 5)
self.assertEqual(f.seek(0, io.SEEK_END), 15)
f.close()
def testTruncateOnWindows(self):
def bug801631():
# SF bug <https://bugs.python.org/issue801631>
# "file.truncate fault on windows"
f = self.FileIO(TESTFN, 'w')
f.write(bytes(range(11)))
f.close()
f = self.FileIO(TESTFN,'r+')
data = f.read(5)
if data != bytes(range(5)):
self.fail("Read on file opened for update failed %r" % data)
if f.tell() != 5:
self.fail("File pos after read wrong %d" % f.tell())
f.truncate()
if f.tell() != 5:
self.fail("File pos after ftruncate wrong %d" % f.tell())
f.close()
size = os.path.getsize(TESTFN)
if size != 5:
self.fail("File size after ftruncate wrong %d" % size)
try:
bug801631()
finally:
os.unlink(TESTFN)
def testAppend(self):
try:
f = open(TESTFN, 'wb')
f.write(b'spam')
f.close()
f = open(TESTFN, 'ab')
f.write(b'eggs')
f.close()
f = open(TESTFN, 'rb')
d = f.read()
f.close()
self.assertEqual(d, b'spameggs')
finally:
try:
os.unlink(TESTFN)
except:
pass
def testInvalidInit(self):
self.assertRaises(TypeError, self.FileIO, "1", 0, 0)
def testWarnings(self):
with check_warnings(quiet=True) as w:
self.assertEqual(w.warnings, [])
self.assertRaises(TypeError, self.FileIO, [])
self.assertEqual(w.warnings, [])
self.assertRaises(ValueError, self.FileIO, "/some/invalid/name", "rt")
self.assertEqual(w.warnings, [])
def testUnclosedFDOnException(self):
class MyException(Exception): pass
class MyFileIO(self.FileIO):
def __setattr__(self, name, value):
if name == "name":
raise MyException("blocked setting name")
return super(MyFileIO, self).__setattr__(name, value)
fd = os.open(__file__, os.O_RDONLY)
self.assertRaises(MyException, MyFileIO, fd)
os.close(fd) # should not raise OSError(EBADF)
class COtherFileTests(OtherFileTests, unittest.TestCase):
FileIO = _io.FileIO
modulename = '_io'
@cpython_only
def testInvalidFd_overflow(self):
# Issue 15989
_testcapi = import_module("_testcapi")
self.assertRaises(TypeError, self.FileIO, _testcapi.INT_MAX + 1)
self.assertRaises(TypeError, self.FileIO, _testcapi.INT_MIN - 1)
def test_open_code(self):
# Check that the default behaviour of open_code matches
# open("rb")
with self.FileIO(__file__, "rb") as f:
expected = f.read()
with _io.open_code(__file__) as f:
actual = f.read()
self.assertEqual(expected, actual)
class PyOtherFileTests(OtherFileTests, unittest.TestCase):
FileIO = _pyio.FileIO
modulename = '_pyio'
def test_open_code(self):
# Check that the default behaviour of open_code matches
# open("rb")
with self.FileIO(__file__, "rb") as f:
expected = f.read()
with check_warnings(quiet=True) as w:
# Always test _open_code_with_warning
with _pyio._open_code_with_warning(__file__) as f:
actual = f.read()
self.assertEqual(expected, actual)
self.assertNotEqual(w.warnings, [])
def tearDownModule():
# Historically, these tests have been sloppy about removing TESTFN.
# So get rid of it no matter what.
if os.path.exists(TESTFN):
os.unlink(TESTFN)
if __name__ == '__main__':
unittest.main()