add missing reference

.changeset/green-pears-call.md

@@ -0,0 +1,2 @@
+---
+---

smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/StructuredMemberWriter.java

@@ -611,9 +611,10 @@ private void writeConstraintValidatorType(TypeScriptWriter writer, Shape shape)
             Shape collectionMemberTargetShape = model.expectShape(collectionMemberShape.getTarget());
             writer.writeInline("Iterable<$T>", getSymbolForValidatedType(collectionMemberTargetShape));
         } else if (shape.isMapShape()) {
+            MapShape mapShape = shape.asMapShape().get();
             writer.writeInline("Record<$T, $T>",
-                getSymbolForValidatedType(((MapShape) shape).getKey()),
-                getSymbolForValidatedType(((MapShape) shape).getValue())
+                getSymbolForValidatedType(mapShape.getKey()),
+                getSymbolForValidatedType(mapShape.getValue())
             );
         } else if (shape instanceof SimpleShape) {
             writer.writeInline("$T", getSymbolForValidatedType(shape));

smithy-typescript-codegen/src/main/java/software/amazon/smithy/typescript/codegen/SymbolVisitor.java

@@ -196,6 +196,7 @@ public Symbol mapShape(MapShape shape) {
         Symbol key = toSymbol(shape.getKey());
         Symbol value = toSymbol(shape.getValue());
         return createSymbolBuilder(shape, format("Record<%s, %s>", key.getName(), value.getName()), null)
+                .addReference(key)
                 .addReference(value)
                 .build();
     }