import asyncio from sanic import Sanic def test_bad_request_response(): app = Sanic('test_bad_request_response') lines = [] async def _request(sanic, loop): connect = asyncio.open_connection('127.0.0.1', 42101) reader, writer = await connect writer.write(b'not http') while True: line = await reader.readline() if not line: break lines.append(line) app.stop() app.run(host='127.0.0.1', port=42101, debug=False, after_start=_request) assert lines[0] == b'HTTP/1.1 400 Bad Request\r\n' assert lines[-1] == b'Error: Bad Request'