support mappings in vdom() constructor

Author: rmorshea

idom/core/vdom.py

@@ -27,7 +27,7 @@ class VdomDict(_VdomDictRequired, _VdomDictOptional):
 
 
 _TagArg = str
-_AttributesAndChildrenArg = Union[Mapping[str, Any], Iterable[Any]]
+_AttributesAndChildrenArg = Union[Mapping[str, Any], str, Iterable[Any], Any]
 _EventHandlersArg = Optional[EventsMapping]
 _ImportSourceArg = Optional[ImportSourceDict]
 
@@ -59,11 +59,15 @@ def vdom(
 
     began_children = False
     for argument in attributes_and_children:
-        if isinstance(argument, dict) and "tagName" not in argument:
-            if began_children:
-                raise ValueError("Attribute dictionaries should precede child lists.")
-            attributes.update(argument)
-        elif isinstance(argument, (list, tuple)):
+        if isinstance(argument, Mapping):
+            if "tagName" not in argument:
+                if began_children:
+                    raise ValueError("Attribute dictionaries should precede children.")
+                attributes.update(argument)
+            else:
+                children.append(argument)
+                began_children = True
+        elif not isinstance(argument, str) and isinstance(argument, Iterable):
             children.extend(argument)
             began_children = True
         else:

tests/test_core/test_vdom.py

@@ -68,6 +68,14 @@ async def handler(event):
             idom.vdom("div", {"tagName": "div"}),
             {"tagName": "div", "children": [{"tagName": "div"}]},
         ),
+        (
+            idom.vdom("div", (i for i in range(3))),
+            {"tagName": "div", "children": [0, 1, 2]},
+        ),
+        (
+            idom.vdom("div", map(lambda x: x ** 2, [1, 2, 3])),
+            {"tagName": "div", "children": [1, 4, 9]},
+        ),
     ],
 )
 def test_simple_node_construction(actual, expected):