Improve external http client typing and add tests

hyperglass/external/generic.py

@@ -1,20 +1,29 @@
 """Session handler for Generic HTTP API endpoint."""
 
+# Standard Library
+import typing as t
+
 # Project
 from hyperglass.log import log
-from hyperglass.external._base import BaseExternal
 from hyperglass.models.webhook import Webhook
 
+# Local
+from ._base import BaseExternal
+
+if t.TYPE_CHECKING:
+    # Project
+    from hyperglass.models.config.logging import Http
+
 
 class GenericHook(BaseExternal, name="Generic"):
     """Slack session handler."""
 
-    def __init__(self, config):
+    def __init__(self: "GenericHook", config: "Http") -> None:
         """Initialize external base class with http connection details."""
 
         super().__init__(base_url=f"{config.host.scheme}://{config.host.host}", config=config)
 
-    async def send(self, query):
+    async def send(self: "GenericHook", query: t.Dict[str, t.Any]):
         """Send an incoming webhook to http endpoint."""
 
         payload = Webhook(**query)