def test_readonly(self):
buffer = self.make_buffer(b"abc")
cursor = Cursor(buffer, readonly=True)
self.assertFalse(cursor.writable())
self.assertRaises(io.UnsupportedOperation, cursor.write, b"blah\n")
self.assertRaises(io.UnsupportedOperation, cursor.writelines,
[b"blah\n"])
def test_writelines_overflow(self):
buffer = self.make_buffer(bytearray(8))
cursor = Cursor(buffer)
cursor.writelines([b"abc\n", b"def\n"])
self.assertEqual(bytes(buffer), b"abc\ndef\n")
self.assertEqual(cursor.seek(0), 0)
self.assertRaises(BufferError, cursor.writelines,
[b"123\n", b"456\n", b"789\n"])
self.assertEqual(bytes(buffer), b"123\n456\n")
def test_tell(self):
cursor = Cursor(self.make_buffer(b"abcdefghijkl"))
self.assertEqual(cursor.tell(), 0)
cursor.read(4)
self.assertEqual(cursor.tell(), 4)
cursor.read()
self.assertEqual(cursor.tell(), 12)
def test_seek_overflow(self):
buffer = self.make_buffer(b"abcd")
cursor = Cursor(buffer, readonly=True)
self.assertEqual(cursor.seek(2), 2)
self.assertRaises(OverflowError,
cursor.seek,
sys.maxsize - 1,
whence=os.SEEK_CUR)
self.assertRaises(OverflowError,
cursor.seek,
sys.maxsize - 1,
whence=os.SEEK_END)
def test_write_overflow(self):
buffer = self.make_buffer(bytearray(10))
cursor = Cursor(buffer)
self.assertEqual(cursor.write(b"0123456789"), 10)
self.assertEqual(cursor.write(b""), 0)
self.assertRaises(BufferError, cursor.write, b"abc")
cursor.seek(-2, whence=os.SEEK_END)
self.assertRaises(BufferError, cursor.write, b"abc")
cursor.seek(-3, whence=os.SEEK_END)
self.assertEqual(cursor.write(b"abc"), 3)
self.assertEqual(bytes(buffer), b"0123456abc")
def test_context(self):
buffer = self.make_buffer(b"abcd")
with Cursor(buffer) as cursor:
self.assertEqual(cursor.read(), b"abcd")
self.assertFalse(cursor.closed)
self.assertTrue(cursor.closed)
self.assertRaises(ValueError, cursor.read)
def test_read(self):
cursor = Cursor(self.make_buffer(b"abcdefghijkl"))
self.assertEqual(cursor.read(2), b"ab")
self.assertEqual(cursor.read(3), b"cde")
self.assertEqual(cursor.read(0), b"")
self.assertEqual(cursor.read(), b"fghijkl")
self.assertEqual(cursor.read(2), b"")
self.assertEqual(cursor.read(), b"")
def test_close(self):
cursor = Cursor(self.make_buffer(b"abcd"))
self.assertFalse(cursor.closed)
cursor.close()
self.assertTrue(cursor.closed)
cursor.close()
self.assertTrue(cursor.closed)
def test_getvalue(self):
buffer = self.make_buffer(b"abc")
cursor = Cursor(buffer)
self.assertIs(cursor.getvalue(), buffer)
self.assertIsInstance(cursor.getvalue(), type(buffer))
def test_flags(self):
buf = self.make_buffer(b"abc")
cursor = Cursor(buf)
self.assertEqual(cursor.writable(), False)
self.assertEqual(cursor.readable(), True)
self.assertEqual(cursor.seekable(), True)
self.assertEqual(cursor.isatty(), False)
self.assertEqual(cursor.closed, False)
buf = self.make_buffer(b"abc")
cursor = Cursor(buf, readonly=True)
self.assertEqual(cursor.writable(), False)
self.assertEqual(cursor.readable(), True)
self.assertEqual(cursor.seekable(), True)
self.assertEqual(cursor.isatty(), False)
self.assertEqual(cursor.closed, False)
def test_repr_readonly(self):
buffer = self.make_buffer(b"abcd")
cursor = Cursor(buffer, readonly=True)
self.assertEqual(repr(cursor), "Cursor({!r})".format(buffer))
def test_interface(self):
cursor = Cursor(self.make_buffer(b"abcd"))
self.assertIsInstance(cursor, io.IOBase)
self.assertIsInstance(cursor, io.BufferedIOBase)
def test_write(self):
buffer = self.make_buffer(bytearray(256))
cursor = Cursor(buffer)
self.assertEqual(cursor.write(b"blah."), 5)
self.assertEqual(cursor.seek(0), 0)
self.assertEqual(cursor.read(5), b"blah.")
self.assertEqual(cursor.seek(0), 0)
self.assertEqual(cursor.write(b"Hello."), 6)
self.assertEqual(cursor.tell(), 6)
self.assertEqual(cursor.seek(5), 5)
self.assertEqual(cursor.tell(), 5)
self.assertEqual(cursor.write(b" world\n\n\n"), 9)
self.assertEqual(cursor.seek(0), 0)
self.assertEqual(cursor.write(b"h"), 1)
self.assertRaises(io.UnsupportedOperation, cursor.truncate, 12)
self.assertEqual(cursor.tell(), 1)
value = cursor.getvalue()
self.assertIs(value, buffer)
self.assertEqual(value[:12], self.make_buffer(b"hello world\n"))
def test_repr_write(self):
buffer = self.make_buffer(b"abcd")
cursor = Cursor(buffer)
self.assertEqual(repr(cursor), "Cursor({!r})".format(buffer))