cpython/Lib/test/test_fileio.py

# Adapted from test_file.py by Daniel Stutzbach

import sys
import os
import unittest
from array import array
from weakref import proxy

from test.test_support import TESTFN, findfile, run_unittest
from UserList import UserList

import _fileio

class AutoFileTests(unittest.TestCase):
    # file tests for which a test file is automatically set up

    def setUp(self):
        self.f = _fileio._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.assertEquals(self.f.tell(), p.tell())
        self.f.close()
        self.f = None
        self.assertRaises(ReferenceError, getattr, p, 'tell')

    def testSeekTell(self):
        self.f.write(bytes(range(20)))
        self.assertEquals(self.f.tell(), 20)
        self.f.seek(0)
        self.assertEquals(self.f.tell(), 0)
        self.f.seek(10)
        self.assertEquals(self.f.tell(), 10)
        self.f.seek(5, 1)
        self.assertEquals(self.f.tell(), 15)
        self.f.seek(-5, 1)
        self.assertEquals(self.f.tell(), 10)
        self.f.seek(-5, 2)
        self.assertEquals(self.f.tell(), 15)

    def testAttributes(self):
        # verify expected attributes exist
        f = self.f
        # XXX do we want these?
        #f.name     # merely shouldn't blow up
        #f.mode     # ditto
        #f.closed   # ditto

        # verify the others aren't
        for attr in 'name', 'mode', 'closed':
            self.assertRaises((AttributeError, TypeError), setattr, f, attr, 'oops')

    def testReadinto(self):
        # verify readinto
        self.f.write(bytes([1, 2]))
        self.f.close()
        a = array('b', 'x'*10)
        self.f = _fileio._FileIO(TESTFN, 'r')
        n = self.f.readinto(a)
        self.assertEquals(array('b', [1, 2]), a[:n])

    def testRepr(self):
        # verify repr works
        return # XXX doesn't work yet
        self.assert_(repr(self.f).startswith("<open file '" + TESTFN))

    def testErrors(self):
        f = self.f
        self.assert_(not f.isatty())
        #self.assert_(not f.closed) # XXX Do we want to support these?
        #self.assertEquals(f.name, TESTFN)

        self.assertRaises(TypeError, f.readinto, "")
        f.close()
        #self.assert_(f.closed) # XXX

    def testMethods(self):
        methods = ['fileno', 'isatty', 'read', 'readinto',
                   'seek', 'tell', 'truncate', 'write', 'seekable',
                   'readable', 'writable']
        if sys.platform.startswith('atheos'):
            methods.remove('truncate')

        # __exit__ should close the file
        self.f.__exit__(None, None, None)
        #self.assert_(self.f.closed) # XXX

        for methodname in methods:
            method = getattr(self.f, methodname)
            # should raise on closed file
            self.assertRaises(ValueError, method)

        # file is closed, __exit__ shouldn't do anything
        self.assertEquals(self.f.__exit__(None, None, None), None)
        # it must also return None if an exception was given
        try:
            1/0
        except:
            self.assertEquals(self.f.__exit__(*sys.exc_info()), None)


class OtherFileTests(unittest.TestCase):

    def testAbles(self):
        try:
            f = _fileio._FileIO(TESTFN, "w")
            self.assertEquals(f.readable(), False)
            self.assertEquals(f.writable(), True)
            self.assertEquals(f.seekable(), True)
            f.close()
            
            f = _fileio._FileIO(TESTFN, "r")
            self.assertEquals(f.readable(), True)
            self.assertEquals(f.writable(), False)
            self.assertEquals(f.seekable(), True)
            f.close()
            
            f = _fileio._FileIO(TESTFN, "a+")
            self.assertEquals(f.readable(), True)
            self.assertEquals(f.writable(), True)
            self.assertEquals(f.seekable(), True)
            self.assertEquals(f.isatty(), False)
            f.close()
            
            f = _fileio._FileIO("/dev/tty", "a") # XXX, won't work on e.g., Windows
            self.assertEquals(f.readable(), False)
            self.assertEquals(f.writable(), True)
            ##self.assertEquals(f.seekable(), False) # XXX True on OSX!?
            self.assertEquals(f.isatty(), True)
            f.close()
        finally:
            os.unlink(TESTFN)

    def testModeStrings(self):
        # check invalid mode strings
        for mode in ("", "aU", "wU+", "rb", "rt"):
            try:
                f = _fileio._FileIO(TESTFN, mode)
            except ValueError:
                pass
            else:
                f.close()
                self.fail('%r is an invalid file mode' % mode)

    def testStdin(self):
        ## This causes the interpreter to exit on OSF1 v5.1.
        #if sys.platform != 'osf1V5':
        #    self.assertRaises(IOError, sys.stdin.seek, -1)
        #else:
        #    print((
        #        '  Skipping sys.stdin.seek(-1), it may crash the interpreter.'
        #        ' Test manually.'), file=sys.__stdout__)
        #self.assertRaises(IOError, sys.stdin.truncate)
        # XXX Comment this out since sys.stdin is currently an old style file 
        pass

    def testUnicodeOpen(self):
        # verify repr works for unicode too
        f = _fileio._FileIO(unicode(TESTFN), "w")
        # XXX doesn't work yet:
        ##self.assert_(repr(f).startswith("<open file u'" + TESTFN))
        f.close()
        os.unlink(TESTFN)

    def testBadModeArgument(self):
        # verify that we get a sensible error message for bad mode argument
        bad_mode = "qwerty"
        try:
            f = _fileio._FileIO(TESTFN, bad_mode)
        except ValueError as msg:
            if msg.message != 0:
                s = str(msg)
                if s.find(TESTFN) != -1 or s.find(bad_mode) == -1:
                    self.fail("bad error message for invalid mode: %s" % s)
            # if msg[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 testTruncateOnWindows(self):
        def bug801631():
            # SF bug <http://www.python.org/sf/801631>
            # "file.truncate fault on windows"
            f = _fileio._FileIO(TESTFN, 'w')
            f.write(bytes(range(11)))
            f.close()

            f = _fileio._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 test_main():
    # Historically, these tests have been sloppy about removing TESTFN.
    # So get rid of it no matter what.
    try:
        run_unittest(AutoFileTests, OtherFileTests)
    finally:
        if os.path.exists(TESTFN):
            os.unlink(TESTFN)

if __name__ == '__main__':
    test_main()