chore: remove mapParams from serialize/deserialize

Author: trivikr

codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/JsonShapeDeserVisitor.java

@@ -76,12 +76,11 @@ protected void deserializeMap(GenerationContext context, MapShape shape) {
 
         // Get the right serialization for each entry in the map. Undefined
         // outputs won't have this deserializer invoked.
-        writer.write("const mapParams: any = {};");
-        writer.openBlock("Object.keys(output).forEach(key => {", "});", () -> {
+        writer.openBlock("return Object.keys(output).reduce((acc: any, key: string) => {", "}, {});", () -> {
             // Dispatch to the output value provider for any additional handling.
-            writer.write("mapParams[key] = $L;", target.accept(getMemberVisitor("output[key]")));
+            writer.write("acc[key] = $L;", target.accept(getMemberVisitor("output[key]")));
+            writer.write("return acc;");
         });
-        writer.write("return mapParams;");
     }
 
     @Override

codegen/smithy-aws-typescript-codegen/src/main/java/software/amazon/smithy/aws/typescript/codegen/JsonShapeSerVisitor.java

@@ -79,12 +79,11 @@ public void serializeMap(GenerationContext context, MapShape shape) {
 
         // Get the right serialization for each entry in the map. Undefined
         // inputs won't have this serializer invoked.
-        writer.write("const mapParams: any = {};");
-        writer.openBlock("Object.keys(input).forEach(key => {", "});", () -> {
+        writer.openBlock("return Object.keys(input).reduce((acc: any, key: string) => {", "}, {});", () -> {
             // Dispatch to the input value provider for any additional handling.
-            writer.write("mapParams[key] = $L;", target.accept(getMemberVisitor("input[key]")));
+            writer.write("acc[key] = $L;", target.accept(getMemberVisitor("input[key]")));
+            writer.write("return acc;");
         });
-        writer.write("return mapParams;");
     }
 
     @Override