Fix skipping tests requiring httptools (#1538)

The test suite currently skips some tests when httptools are missing.
However, there are more tests requiring it and they currently fail
if that is the case.  Cover them with necessary skips as well.

tests/middleware/test_logging.py

@@ -7,6 +7,15 @@
 
 from tests.utils import run_server
 from uvicorn import Config
+from uvicorn.protocols.http.h11_impl import H11Protocol
+
+try:
+    from uvicorn.protocols.http.httptools_impl import HttpToolsProtocol
+except ImportError:  # pragma: nocover
+    HttpToolsProtocol = None
+
+
+HTTP_PROTOCOLS = [p for p in [H11Protocol, HttpToolsProtocol] if p is not None]
 
 
 @contextlib.contextmanager
@@ -49,7 +58,7 @@ async def test_trace_logging(caplog, logging_config):
 
 
 @pytest.mark.anyio
-@pytest.mark.parametrize("http_protocol", [("h11"), ("httptools")])
+@pytest.mark.parametrize("http_protocol", HTTP_PROTOCOLS)
 async def test_trace_logging_on_http_protocol(http_protocol, caplog, logging_config):
     config = Config(
         app=app,

tests/protocols/test_http.py

@@ -766,6 +766,7 @@ async def test_invalid_http_request(request_line, protocol_cls, caplog):
     assert b"Invalid HTTP request received." in protocol.transport.buffer
 
 
+@pytest.mark.skipif(HttpToolsProtocol is None, reason="httptools is not installed")
 def test_fragmentation():
     def receive_all(sock):
         chunks = []