Add more gateway tests (jupyter-server#1078)

* add more gateway tests

* fix mock gateway

jupyter_server/gateway/handlers.py

@@ -138,7 +138,7 @@ class GatewayWebSocketClient(LoggingConfigurable):
     """Proxy web socket connection to a kernel/enterprise gateway."""
 
     def __init__(self, **kwargs):
-        super().__init__(**kwargs)
+        super().__init__()
         self.kernel_id = None
         self.ws = None
         self.ws_future: Future = Future()

tests/test_gateway.py

@@ -104,6 +104,12 @@ async def mock_gateway_request(url, **kwargs):
         else:
             raise HTTPError(404, message="Kernelspec does not exist: %s" % requested_kernelspec)
 
+    # Fetch kernelspec asset
+    if endpoint.rfind("/kernelspecs/") >= 0 and method == "GET":
+        response_buf = BytesIO(b"foo")
+        response = await ensure_async(HTTPResponse(request, 200, buffer=response_buf))
+        return response
+
     # Create kernel
     if endpoint.endswith("/api/kernels") and method == "POST":
         json_body = json.loads(kwargs["body"])
@@ -393,7 +399,7 @@ async def test_gateway_class_mappings(init_gateway, jp_serverapp):
     assert jp_serverapp.kernel_spec_manager_class.__name__ == "GatewayKernelSpecManager"
 
 
-async def test_gateway_get_kernelspecs(init_gateway, jp_fetch):
+async def test_gateway_get_kernelspecs(init_gateway, jp_fetch, jp_serverapp):
     # Validate that kernelspecs come from gateway.
     with mocked_gateway:
         r = await jp_fetch("api", "kernelspecs", method="GET")
@@ -412,6 +418,10 @@ async def test_gateway_get_named_kernelspec(init_gateway, jp_fetch):
         kspec_foo = json.loads(r.body.decode("utf-8"))
         assert kspec_foo.get("name") == "kspec_foo"
 
+        r = await jp_fetch("kernelspecs", "kspec_foo", "hi", method="GET")
+        assert r.code == 200
+        assert r.body == b"foo"
+
         with pytest.raises(tornado.httpclient.HTTPClientError) as e:
             await jp_fetch("api", "kernelspecs", "no_such_spec", method="GET")
         assert expected_http_error(e, 404)
@@ -443,7 +453,7 @@ async def test_gateway_session_lifecycle(init_gateway, jp_root_dir, jp_fetch):
     assert await is_kernel_running(jp_fetch, kernel_id) is False
 
 
-async def test_gateway_kernel_lifecycle(init_gateway, jp_fetch):
+async def test_gateway_kernel_lifecycle(init_gateway, jp_serverapp, jp_ws_fetch, jp_fetch):
     # Validate kernel lifecycle functions; create, interrupt, restart and delete.
 
     # create
@@ -452,6 +462,12 @@ async def test_gateway_kernel_lifecycle(init_gateway, jp_fetch):
     # ensure kernel still considered running
     assert await is_kernel_running(jp_fetch, kernel_id) is True
 
+    ws = await jp_ws_fetch("api", "kernels", kernel_id, "channels")
+    ws.ping()
+    ws.write_message(b"hi")
+    ws.on_message(b"hi")
+    ws.close()
+
     # interrupt
     await interrupt_kernel(jp_fetch, kernel_id)