import pytest

import struct

from rpython.rtyper.lltypesystem import lltype, rffi

from rpython.rlib.mutbuffer import MutableStringBuffer

class TestMutableStringBuffer(object):

def test_finish(self):

buf = MutableStringBuffer(4)

buf.setzeros(0, 4)

pytest.raises(ValueError, "buf.as_str()")

s = buf.finish()

assert s == '\x00' * 4

pytest.raises(ValueError, "buf.finish()")

def test_setitem(self):

buf = MutableStringBuffer(4)

buf.setitem(0, 'A')

buf.setitem(1, 'B')

buf.setitem(2, 'C')

buf.setitem(3, 'D')

assert buf.finish() == 'ABCD'

def test_setslice(self):

buf = MutableStringBuffer(6)

buf.setzeros(0, 6)

buf.setslice(2, 'ABCD')

assert buf.finish() == '\x00\x00ABCD'

def test_setzeros(self):

buf = MutableStringBuffer(8)

buf.setslice(0, 'ABCDEFGH')

buf.setzeros(2, 3)

assert buf.finish() == 'AB\x00\x00\x00FGH'

def test_typed_write(self):

expected = struct.pack('ifqd', 0x1234, 123.456, 0x12345678, 789.123)

buf = MutableStringBuffer(24)

buf.typed_write(rffi.INT, 0, 0x1234)

buf.typed_write(rffi.FLOAT, 4, 123.456)

buf.typed_write(rffi.LONGLONG, 8, 0x12345678)

buf.typed_write(rffi.DOUBLE, 16, 789.123)

s = buf.finish()

assert s == expected