fix list of component is a component

reflex/components/core/cond.py

@@ -7,6 +7,7 @@ from typing import Any, overload
 from reflex.components.base.fragment import Fragment
 from reflex.components.component import BaseComponent, Component
 from reflex.style import LIGHT_COLOR_MODE, resolved_color_mode
+from reflex.utils import types
 from reflex.utils.types import safe_issubclass
 from reflex.vars.base import LiteralVar, ReflexCallable, Var
 from reflex.vars.function import ArgsFunctionOperation
@@ -40,7 +41,11 @@ def cond(condition: Any, c1: Any, c2: Any = None) -> Component | Var:
 
     # If the first component is a component, create a Fragment if the second component is not set.
     if isinstance(c1, BaseComponent) or (
-        isinstance(c1, Var) and safe_issubclass(c1._var_type, BaseComponent)
+        isinstance(c1, Var)
+        and (
+            safe_issubclass(c1._var_type, BaseComponent)
+            or types.safe_typehint_issubclass(c1._var_type, list[BaseComponent])
+        )
     ):
         c2 = c2 if c2 is not None else Fragment.create()
 

reflex/utils/types.py

@@ -976,3 +976,19 @@ def typehint_issubclass(possible_subclass: Any, possible_superclass: Any) -> boo
         for provided_arg, accepted_arg in zip(provided_args, accepted_args)
         if accepted_arg is not Any and not isinstance(accepted_arg, TypeVar)
     )
+
+
+def safe_typehint_issubclass(possible_subclass: Any, possible_superclass: Any) -> bool:
+    """Check if a type hint is a subclass of another type hint.
+
+    Args:
+        possible_subclass: The type hint to check.
+        possible_superclass: The type hint to check against.
+
+    Returns:
+        Whether the type hint is a subclass of the other type hint.
+    """
+    try:
+        return typehint_issubclass(possible_subclass, possible_superclass)
+    except Exception:
+        return False

reflex/vars/sequence.py

@@ -996,13 +996,22 @@ class ArrayVar(Var[ARRAY_VAR_TYPE], python_types=(Sequence, set)):
 
         if not callable(fn):
             raise_unsupported_operand_types("foreach", (type(self), type(fn)))
+
         # get the number of arguments of the function
-        num_args = len(inspect.signature(fn).parameters)
-        if num_args > 2:
+        required_num_args = len(
+            [
+                p
+                for p in inspect.signature(fn).parameters.values()
+                if p.default != p.empty
+            ]
+        )
+        if required_num_args > 2:
             raise VarTypeError(
                 "The function passed to foreach should take at most two arguments."
             )
 
+        num_args = len(inspect.signature(fn).parameters)
+
         if (
             hasattr(fn, "__qualname__")
             and fn.__qualname__ == ComponentState.create.__qualname__
@@ -1039,7 +1048,7 @@ class ArrayVar(Var[ARRAY_VAR_TYPE], python_types=(Sequence, set)):
             ).guess_type(),
         )
 
-        if num_args == 1:
+        if required_num_args < 2:
             fn_result = fn(first_arg)  # pyright: ignore [reportCallIssue]
 
             return_value = Var.create(fn_result)