Validate ForNode

Author: thomasmarshall

config.yml

@@ -2547,9 +2547,7 @@ nodes:
           - CallTargetNode
           - IndexTargetNode
           - MultiTargetNode
-          - on error: BackReferenceReadNode # for $& in a end
-          - on error: NumberedReferenceReadNode # for $1 in a end
-          - on error: ErrorRecoveryNode # for in 1..10; end
+          - on error: ErrorRecoveryNode
         comment: |
           The index expression for `for` loops.
 

src/prism.c

@@ -19153,6 +19153,11 @@ parse_expression_prefix(pm_parser_t *parser, pm_binding_power_t binding_power, b
             parser_warn_indentation_mismatch(parser, opening_newline_index, &for_keyword, false, false);
             expect1_opening(parser, PM_TOKEN_KEYWORD_END, PM_ERR_FOR_TERM, &for_keyword);
 
+            PM_VALIDATE_NODE_TYPE(parser, index,
+                PM_LOCAL_VARIABLE_TARGET_NODE, PM_INSTANCE_VARIABLE_TARGET_NODE, PM_CLASS_VARIABLE_TARGET_NODE, PM_GLOBAL_VARIABLE_TARGET_NODE,
+                PM_CONSTANT_TARGET_NODE, PM_CONSTANT_PATH_TARGET_NODE, PM_CALL_TARGET_NODE, PM_INDEX_TARGET_NODE,
+                PM_MULTI_TARGET_NODE);
+
             return UP(pm_for_node_create(parser, index, collection, statements, &for_keyword, &in_keyword, &do_keyword, &parser->previous));
         }
         case PM_TOKEN_KEYWORD_IF:

test/prism/result/error_recovery_test.rb

@@ -54,15 +54,17 @@ def test_for_node_index_back_reference
       refute result.success?
 
       node = result.value.statements.body.first
-      assert_kind_of BackReferenceReadNode, node.index
+      assert_kind_of ErrorRecoveryNode, node.index
+      assert_kind_of BackReferenceReadNode, node.index.child
     end
 
     def test_for_node_index_numbered_reference
       result = Prism.parse("for $1 in a; end")
       refute result.success?
 
       node = result.value.statements.body.first
-      assert_kind_of NumberedReferenceReadNode, node.index
+      assert_kind_of ErrorRecoveryNode, node.index
+      assert_kind_of NumberedReferenceReadNode, node.index.child
     end
 
     def test_for_node_index_missing
@@ -71,6 +73,7 @@ def test_for_node_index_missing
 
       node = result.value.statements.body.first
       assert_kind_of ErrorRecoveryNode, node.index
+      assert_nil node.index.child
     end
 
     def test_interpolated_string_node_parts_xstring