test: update malformed url test

tests/test_bad_request.py

@@ -24,4 +24,22 @@ def test_bad_request_response(app):
 
 
 def test_malformed_uri_bad_request(app):
-    assert False
+    lines = []
+
+    app.get("/")(lambda x: ...)
+
+    @app.listener("after_server_start")
+    async def _request(sanic, loop):
+        connect = asyncio.open_connection("127.0.0.1", 42101)
+        reader, writer = await connect
+        writer.write(b"GET /\r\nHost: ---.com\r\n\r\n")
+        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)
+    assert lines[0] == b"HTTP/1.1 400 Bad Request\r\n"
+    assert b"Bad Request" in lines[-2]