chore: basic, coarse type hints for all watcher deltas

Author: dimaqq

juju/client/overrides.py

@@ -1,8 +1,9 @@
 # Copyright 2023 Canonical Ltd.
 # Licensed under the Apache V2, see LICENCE file for details.
+from __future__ import annotations
 
 import re
-from collections import namedtuple
+from typing import Any, NamedTuple
 
 from . import _client, _definitions
 from .facade import ReturnMapping, Type, TypeEncoder
@@ -22,6 +23,12 @@
 ]
 
 
+class _Change(NamedTuple):
+    entity: str
+    type: str
+    data: dict[str, Any]
+
+
 class Delta(Type):
     """A single websocket delta.
 
@@ -42,12 +49,11 @@ class Delta(Type):
     _toSchema = {"deltas": "deltas"}
     _toPy = {"deltas": "deltas"}
 
-    def __init__(self, deltas=None):
+    def __init__(self, deltas: tuple[str, str, dict[str, Any]]):
         """:param deltas: [str, str, object]"""
         self.deltas = deltas
 
-        Change = namedtuple("Change", "entity type data")
-        change = Change(*self.deltas)
+        change = _Change(*self.deltas)
 
         self.entity = change.entity
         self.type = change.type

juju/delta.py

@@ -1,10 +1,12 @@
 # Copyright 2023 Canonical Ltd.
 # Licensed under the Apache V2, see LICENCE file for details.
+from __future__ import annotations
 
-from .client import client
+from . import model
+from .client import client, overrides
 
 
-def get_entity_delta(d):
+def get_entity_delta(d: overrides.Delta):
     return _delta_types[d.entity](d.deltas)
 
 
@@ -13,12 +15,14 @@ def get_entity_class(entity_type):
 
 
 class EntityDelta(client.Delta):
-    def get_id(self):
+    data: dict[str, str]
+
+    def get_id(self) -> str:
         return self.data["id"]
 
     @classmethod
-    def get_entity_class(cls):
-        return None
+    def get_entity_class(cls) -> type[model.ModelEntity]:
+        raise NotImplementedError()
 
 
 class ActionDelta(EntityDelta):