def _get_requested_range(request: Request) -> Optional[Range]:
# http://svn.tools.ietf.org/svn/wg/httpbis/specs/rfc7233.html#rfc.section.3.1
# A server must ignore a Range header field received with a request method
# other than GET
if request.method != "GET":
return None
# NB: only the first Range request header is taken into consideration;
# if the HTTP contains several Range headers, only the first is used
range_header = request.get_first_header(b"range")
if not range_header:
return None
try:
value = Range.parse(range_header)
except InvalidRangeValue:
raise BadRequest("Invalid Range header")
else:
# An origin server must ignore a Range header field that contains
# a range unit it does not understand.
if value.unit != "bytes":
return None
return value
def test_range_throws_value_error_for_invalid_value():
with pytest.raises(ValueError):
Range.parse("bytes=100-200, 400-600, 300-500=50-150")
def test_parse_range(value, expected_range):
parsed_range = Range.parse(value)
assert parsed_range == expected_range
def test_raise_for_invalid_value(invalid_value):
with pytest.raises(InvalidRangeValue):
Range.parse(invalid_value)
