def test_can_write_one_then_read_as_two():
b = ByteStream()
b.write(b"hello, world")
read = b.read(6)
assert read.tobytes() == b"hello,"
read = b.read(6)
assert read.tobytes() == b" world"
def test_can_resume_reading_after_nothing_available():
b = ByteStream()
b.write(b"hello")
b.read(5)
read = b.read(1)
assert read is None
b.write(b"world")
read = b.read(5)
assert read.tobytes() == b"world"
def test_can_write_several_then_read_across_boundaries():
b = ByteStream()
b.write(b"aaa")
b.write(b"bbb")
b.write(b"ccc")
b.write(b"ddd")
read = b.read(4)
assert read.tobytes() == b"aaab"
read = b.read(4)
assert read.tobytes() == b"bbcc"
read = b.read(4)
assert read.tobytes() == b"cddd"
def test_distance_changes_after_read():
b = ByteStream()
b.write(b"abcbca")
distance = b.until(97)
assert distance == 1
distance = b.until(98)
assert distance == 2
distance = b.until(99)
assert distance == 3
b.read(3)
distance = b.until(97)
assert distance == 3
distance = b.until(98)
assert distance == 1
distance = b.until(99)
assert distance == 2
def test_can_measure_how_much_available():
b = ByteStream()
assert b.available() == 0
b.write(b"hello")
assert b.available() == 5
b.read(2)
assert b.available() == 3
b.read(2)
assert b.available() == 1
b.read(2)
assert b.available() == 1
b.read(1)
assert b.available() == 0
def test_reading_nothing_does_nothing():
b = ByteStream()
b.write(b"hello")
assert b.available() == 5
b.read(0)
assert b.available() == 5
def test_read_returns_none_if_not_enough_available():
b = ByteStream()
b.write(b"hello")
read = b.read(10)
assert read is None
def test_read_returns_none_if_nothing_more_available():
b = ByteStream()
b.write(b"hello")
b.read(5)
read = b.read(1)
assert read is None
def test_read_returns_none_if_nothing_available():
b = ByteStream()
read = b.read(1)
assert read is None
def test_can_write_then_read_simple_stream():
b = ByteStream()
b.write(b"hello")
read = b.read(5)
assert read.tobytes() == b"hello"
