Fixed issue with Any, empty Dict/List and None in `callback_t…

…ypecheck` (#639)

tests/test_callback_typecheck.py

@@ -1,4 +1,4 @@
-from typing import Dict, List, Optional, TypedDict, Union
+from typing import Any, Dict, List, Optional, TypedDict, Union
 from enum import Enum
 from webviz_config.utils import callback_typecheck, ConversionError
 
@@ -168,3 +168,29 @@ def expect_union_string_list(
     assert callback_typecheck(expect_union_string_list)({"1": "1"}) == {"1": "1"}
     assert callback_typecheck(expect_union_string_list)(None) is None
     assert callback_typecheck(expect_union_string_list)(1) == 1
+
+    ############################################################
+
+    def expect_optional_dict(arg: Optional[Dict[str, str]]) -> Optional[Dict[str, str]]:
+        return arg
+
+    assert callback_typecheck(expect_optional_dict)({"1": "1"}) == {"1": "1"}
+    assert callback_typecheck(expect_optional_dict)(None) is None
+
+    ############################################################
+
+    def expect_optional_dict_without_types(arg: Optional[Dict]) -> Optional[Dict]:
+        return arg
+
+    assert callback_typecheck(expect_optional_dict_without_types)({"1": "1"}) == {
+        "1": "1"
+    }
+    assert callback_typecheck(expect_optional_dict_without_types)(None) is None
+
+    ############################################################
+
+    def expect_optional_dict_with_any(arg: Optional[Dict[Any, Any]]) -> Optional[dict]:
+        return arg
+
+    assert callback_typecheck(expect_optional_dict_with_any)({"1": "1"}) == {"1": "1"}
+    assert callback_typecheck(expect_optional_dict_with_any)(None) is None

webviz_config/utils/_callback_typecheck.py

@@ -10,10 +10,13 @@ class ConversionError(Exception):
 
 
 def _isinstance(arg: Any, annotation: Any) -> bool:
-    # pylint: disable=too-many-return-statements
-    if annotation is None:
+    # pylint: disable=too-many-return-statements, too-many-branches
+    if annotation is type(None) or annotation is None:
         return arg is None
 
+    if annotation is Any:
+        return True
+
     if get_origin(annotation) is None:
         try:
             return isinstance(arg, annotation)
@@ -27,15 +30,19 @@ def _isinstance(arg: Any, annotation: Any) -> bool:
 
     if get_origin(annotation) is list and isinstance(arg, list):
         result = True
-        for annotation_arg in arg:
-            result &= _isinstance(annotation_arg, get_args(annotation)[0])
+        type_args = get_args(annotation)
+        if len(type_args) == 1:
+            for annotation_arg in arg:
+                result &= _isinstance(annotation_arg, type_args[0])
         return result
 
     if get_origin(annotation) is dict and isinstance(arg, dict):
         result = True
-        for key, value in arg.items():
-            result &= _isinstance(key, get_args(annotation)[0])
-            result &= _isinstance(value, get_args(annotation)[1])
+        type_args = get_args(annotation)
+        if len(type_args) == 2:
+            for key, value in arg.items():
+                result &= _isinstance(key, type_args[0])
+                result &= _isinstance(value, type_args[1])
         return result
 
     return False