localstack · MEPalma · Mar 13, 2025 · Mar 3, 2025 · Mar 13, 2025
@@ -299,7 +299,7 @@ iterator_decl: ITERATOR COLON LBRACE iterator_decl_item (COMMA iterator_decl_ite
 
 iterator_decl_item: startat_decl | states_decl | comment_decl | processor_config_decl;
 
-item_selector_decl: ITEMSELECTOR COLON payload_tmpl_decl;
+item_selector_decl: ITEMSELECTOR COLON assign_template_value_object;
 
 item_reader_decl: ITEMREADER COLON LBRACE items_reader_field (COMMA items_reader_field)* RBRACE;
 

@@ -336,7 +336,7 @@ def serializedATN():
         1,0,0,0,836,834,1,0,0,0,837,838,5,6,0,0,838,141,1,0,0,0,839,844,
         3,6,3,0,840,844,3,16,8,0,841,844,3,8,4,0,842,844,3,128,64,0,843,
         839,1,0,0,0,843,840,1,0,0,0,843,841,1,0,0,0,843,842,1,0,0,0,844,
-        143,1,0,0,0,845,846,5,87,0,0,846,847,5,2,0,0,847,848,3,64,32,0,848,
+        143,1,0,0,0,845,846,5,87,0,0,846,847,5,2,0,0,847,848,3,80,40,0,848,
         145,1,0,0,0,849,850,5,102,0,0,850,851,5,2,0,0,851,852,5,5,0,0,852,
         857,3,148,74,0,853,854,5,1,0,0,854,856,3,148,74,0,855,853,1,0,0,
         0,856,859,1,0,0,0,857,855,1,0,0,0,857,858,1,0,0,0,858,860,1,0,0,
@@ -7873,8 +7873,8 @@ def ITEMSELECTOR(self):
         def COLON(self):
             return self.getToken(ASLParser.COLON, 0)
 
-        def payload_tmpl_decl(self):
-            return self.getTypedRuleContext(ASLParser.Payload_tmpl_declContext,0)
+        def assign_template_value_object(self):
+            return self.getTypedRuleContext(ASLParser.Assign_template_value_objectContext,0)
 
 
         def getRuleIndex(self):
@@ -7908,7 +7908,7 @@ def item_selector_decl(self):
             self.state = 846
             self.match(ASLParser.COLON)
             self.state = 847
-            self.payload_tmpl_decl()
+            self.assign_template_value_object()
         except RecognitionException as re:
             localctx.exception = re
             self._errHandler.reportError(self, re)

@@ -1,15 +1,17 @@
 from typing import Final
 
-from localstack.services.stepfunctions.asl.component.common.payload.payloadvalue.payloadtmpl.payload_tmpl import (
-    PayloadTmpl,
+from localstack.services.stepfunctions.asl.component.common.assign.assign_template_value_object import (
+    AssignTemplateValueObject,
 )
 from localstack.services.stepfunctions.asl.component.eval_component import EvalComponent
 from localstack.services.stepfunctions.asl.eval.environment import Environment
 
 
 class ItemSelector(EvalComponent):
-    def __init__(self, payload_tmpl: PayloadTmpl):
-        self.payload_tmpl: Final[PayloadTmpl] = payload_tmpl
+    template_value_object: Final[AssignTemplateValueObject]
+
+    def __init__(self, template_value_object: AssignTemplateValueObject):
+        self.template_value_object = template_value_object
 
     def _eval_body(self, env: Environment) -> None:
-        self.payload_tmpl.eval(env=env)
+        self.template_value_object.eval(env=env)
@@ -918,8 +918,10 @@ def visitIterator_decl(self, ctx: ASLParser.Iterator_declContext) -> IteratorDec
         )
 
     def visitItem_selector_decl(self, ctx: ASLParser.Item_selector_declContext) -> ItemSelector:
-        payload_tmpl: PayloadTmpl = self.visit(ctx.payload_tmpl_decl())
-        return ItemSelector(payload_tmpl=payload_tmpl)
+        template_value_object = self.visitAssign_template_value_object(
+            ctx=ctx.assign_template_value_object()
+        )
+        return ItemSelector(template_value_object=template_value_object)
 
     def visitItem_reader_decl(self, ctx: ASLParser.Item_reader_declContext) -> ItemReader:
         props = StateProps()

@@ -127,6 +127,9 @@ class ScenariosTemplate(TemplateLoader):
     MAP_STATE_ITEM_SELECTOR: Final[str] = os.path.join(
         _THIS_FOLDER, "statemachines/map_state_item_selector.json5"
     )
+    MAP_STATE_ITEM_SELECTOR_JSONATA: Final[str] = os.path.join(
+        _THIS_FOLDER, "statemachines/map_state_item_selector_jsonata.json5"
+    )
     MAP_STATE_ITEM_SELECTOR_PARAMETERS: Final[str] = os.path.join(
         _THIS_FOLDER, "statemachines/map_state_item_selector_parameters.json5"
     )

@@ -0,0 +1,36 @@
+{
+  "QueryLanguage": "JSONata",
+  "StartAt": "Start",
+  "States": {
+    "Start": {
+      "Type": "Pass",
+      "Assign": {
+        "ItemsVar": ["Item1", "Item2"]
+      },
+      "Next": "MapIterateState"
+    },
+    "MapIterateState": {
+      "Type": "Map",
+      "MaxConcurrency": 1,
+      "Items": "{% $ItemsVar %}",
+      "ItemSelector": {
+        "map_item_value": "{% $states.context.Map.Item.Value %}",
+        "var_sample": "{% $ItemsVar %}",
+        "string_literal": "string literal"
+      },
+      "ItemProcessor": {
+        "ProcessorConfig": {
+          "Mode": "INLINE"
+        },
+        "StartAt": "Pass",
+        "States": {
+          "Pass": {
+            "Type": "Pass",
+            "End": true
+          }
+        }
+      },
+      "End": true
+    }
+  }
+}
@@ -787,16 +787,21 @@ def test_map_state_config_inline_parameters(
         )
 
     @markers.aws.validated
+    @pytest.mark.parametrize(
+        "template_path",
+        [ST.MAP_STATE_ITEM_SELECTOR, ST.MAP_STATE_ITEM_SELECTOR_JSONATA],
+        ids=["MAP_STATE_ITEM_SELECTOR", "MAP_STATE_ITEM_SELECTOR_JSONATA"],
+    )
     def test_map_state_item_selector(
         self,
         aws_client,
         create_state_machine_iam_role,
         create_state_machine,
         sfn_snapshot,
+        template_path,
     ):
-        template = ST.load_sfn_template(ST.MAP_STATE_ITEM_SELECTOR)
+        template = ST.load_sfn_template(template_path)
         definition = json.dumps(template)
-
         exec_input = json.dumps({})
         create_and_record_execution(
             aws_client,