def test_peek(self):
buffer = ByteBuffer()
buffer.write(b"abcdefghi")
assert buffer.peek(slice(0, 1)) == b"a"
assert buffer.peek(slice(3, 6)) == b"def"
assert buffer.peek(slice(-2, -1)) == b"h"
assert buffer.read() == b"abcdefghi"
def test_read_all(self):
buffer = ByteBuffer()
buffer.write(b"abcdefghi")
assert buffer.read() == b"abcdefghi"
assert buffer.read() == b""
def test_discard_all(self):
buffer = ByteBuffer()
buffer.write(b"abcdefghi")
assert buffer.discard() is None
assert buffer.read() == b""