avoid runtime errors on iterating over non-array (#5796)

* avoid runtime errors on iterating over non-array

* add test

* handle object keys values entries more gracefully if they are not a dict

Author: adhami3310

reflex/compiler/templates.py

@@ -86,7 +86,7 @@ def render_iterable_tag(component: Any) -> str:
         children_rendered = "".join(
             [_RenderUtils.render(child) for child in component.get("children", [])]
         )
-        return f"{component['iterable_state']}.map(({component['arg_name']},{component['arg_index']})=>({children_rendered}))"
+        return f"Array.prototype.map.call({component['iterable_state']} ?? [],(({component['arg_name']},{component['arg_index']})=>({children_rendered})))"
 
     @staticmethod
     def render_match_tag(component: Any) -> str:

reflex/vars/object.py

@@ -479,14 +479,9 @@ def object_keys_operation(value: ObjectVar):
     Returns:
         The keys of the object.
     """
-    if not types.is_optional(value._var_type):
-        return var_operation_return(
-            js_expression=f"Object.keys({value})",
-            var_type=list[str],
-        )
     return var_operation_return(
-        js_expression=f"((value) => value ?? undefined === undefined ? undefined : Object.keys(value))({value})",
-        var_type=(list[str] | None),
+        js_expression=f"Object.keys({value} ?? {{}})",
+        var_type=list[str],
     )
 
 
@@ -500,14 +495,9 @@ def object_values_operation(value: ObjectVar):
     Returns:
         The values of the object.
     """
-    if not types.is_optional(value._var_type):
-        return var_operation_return(
-            js_expression=f"Object.values({value})",
-            var_type=list[value._value_type()],
-        )
     return var_operation_return(
-        js_expression=f"((value) => value ?? undefined === undefined ? undefined : Object.values(value))({value})",
-        var_type=(list[value._value_type()] | None),
+        js_expression=f"Object.values({value} ?? {{}})",
+        var_type=list[value._value_type()],
     )
 
 
@@ -521,14 +511,9 @@ def object_entries_operation(value: ObjectVar):
     Returns:
         The entries of the object.
     """
-    if not types.is_optional(value._var_type):
-        return var_operation_return(
-            js_expression=f"Object.entries({value})",
-            var_type=list[tuple[str, value._value_type()]],
-        )
     return var_operation_return(
-        js_expression=f"((value) => value ?? undefined === undefined ? undefined : Object.entries(value))({value})",
-        var_type=(list[tuple[str, value._value_type()]] | None),
+        js_expression=f"Object.entries({value} ?? {{}})",
+        var_type=list[tuple[str, value._value_type()]],
     )
 
 

tests/integration/test_var_operations.py

@@ -575,6 +575,29 @@ def index():
             rx.text(ArrayVar.range(2, 10, 2).join(","), id="list_join_range2"),
             rx.text(ArrayVar.range(5, 0, -1).join(","), id="list_join_range3"),
             rx.text(ArrayVar.range(0, 3).join(","), id="list_join_range4"),
+            rx.box(
+                # Test that foreach works with various non-array inputs without throwing
+                rx.foreach(
+                    rx.Var("undefined").to(list),
+                    rx.text.span,
+                ),
+                rx.foreach(
+                    rx.Var("null").to(list),
+                    rx.text.span,
+                ),
+                rx.foreach(
+                    rx.Var("({})").to(list),
+                    rx.text.span,
+                ),
+                rx.foreach(
+                    rx.Var("2").to(list),
+                    rx.text.span,
+                ),
+                rx.foreach(
+                    rx.Var("false").to(list),
+                    rx.text.span,
+                ),
+            ),
             rx.box(
                 rx.foreach(
                     ArrayVar.range(0, 2),

tests/units/components/core/test_foreach.py

@@ -171,28 +171,28 @@ def display_color_index_tuple(color):
             ForEachState.primary_color,
             display_primary_colors,
             {
-                "iterable_state": f"Object.entries({ForEachState.get_full_name()}.primary_color{FIELD_MARKER})",
+                "iterable_state": f"Object.entries({ForEachState.get_full_name()}.primary_color{FIELD_MARKER} ?? {{}})",
             },
         ),
         (
             ForEachState.color_with_shades,
             display_color_with_shades,
             {
-                "iterable_state": f"Object.entries({ForEachState.get_full_name()}.color_with_shades{FIELD_MARKER})",
+                "iterable_state": f"Object.entries({ForEachState.get_full_name()}.color_with_shades{FIELD_MARKER} ?? {{}})",
             },
         ),
         (
             ForEachState.nested_colors_with_shades,
             display_nested_color_with_shades,
             {
-                "iterable_state": f"Object.entries({ForEachState.get_full_name()}.nested_colors_with_shades{FIELD_MARKER})",
+                "iterable_state": f"Object.entries({ForEachState.get_full_name()}.nested_colors_with_shades{FIELD_MARKER} ?? {{}})",
             },
         ),
         (
             ForEachState.nested_colors_with_shades,
             display_nested_color_with_shades_v2,
             {
-                "iterable_state": f"Object.entries({ForEachState.get_full_name()}.nested_colors_with_shades{FIELD_MARKER})",
+                "iterable_state": f"Object.entries({ForEachState.get_full_name()}.nested_colors_with_shades{FIELD_MARKER} ?? {{}})",
             },
         ),
         (

tests/units/test_var.py

@@ -1079,15 +1079,16 @@ def test_object_operations():
     object_var = LiteralObjectVar.create({"a": 1, "b": 2, "c": 3})
 
     assert (
-        str(object_var.keys()) == 'Object.keys(({ ["a"] : 1, ["b"] : 2, ["c"] : 3 }))'
+        str(object_var.keys())
+        == 'Object.keys(({ ["a"] : 1, ["b"] : 2, ["c"] : 3 }) ?? {})'
     )
     assert (
         str(object_var.values())
-        == 'Object.values(({ ["a"] : 1, ["b"] : 2, ["c"] : 3 }))'
+        == 'Object.values(({ ["a"] : 1, ["b"] : 2, ["c"] : 3 }) ?? {})'
     )
     assert (
         str(object_var.entries())
-        == 'Object.entries(({ ["a"] : 1, ["b"] : 2, ["c"] : 3 }))'
+        == 'Object.entries(({ ["a"] : 1, ["b"] : 2, ["c"] : 3 }) ?? {})'
     )
     assert str(object_var.a) == '({ ["a"] : 1, ["b"] : 2, ["c"] : 3 })["a"]'
     assert str(object_var["a"]) == '({ ["a"] : 1, ["b"] : 2, ["c"] : 3 })["a"]'
@@ -1129,11 +1130,11 @@ def test_type_chains():
     )
     assert (
         str(object_var.keys()[0].upper())
-        == 'Object.keys(({ ["a"] : 1, ["b"] : 2, ["c"] : 3 })).at(0).toUpperCase()'
+        == 'Object.keys(({ ["a"] : 1, ["b"] : 2, ["c"] : 3 }) ?? {}).at(0).toUpperCase()'
     )
     assert (
         str(object_var.entries()[1][1] - 1)
-        == '(Object.entries(({ ["a"] : 1, ["b"] : 2, ["c"] : 3 })).at(1).at(1) - 1)'
+        == '(Object.entries(({ ["a"] : 1, ["b"] : 2, ["c"] : 3 }) ?? {}).at(1).at(1) - 1)'
     )
     assert (
         str(object_var["c"] + object_var["b"])  # pyright: ignore [reportCallIssue, reportOperatorIssue]