remove resultType from StepOperation

Author: zhongkechen

sdk/src/main/java/com/amazonaws/lambda/durable/operation/StepOperation.java

@@ -33,26 +33,13 @@ public class StepOperation<T> implements DurableOperation<T> {
     private final String operationId;
     private final String name;
     private final Supplier<T> function;
-    private final Class<T> resultType;
     private final TypeToken<T> resultTypeToken;
     private final StepConfig config;
     private final ExecutionManager executionManager;
     private final DurableLogger durableLogger;
     private final SerDes serDes;
     private final Phaser phaser;
 
-    public StepOperation(
-            String operationId,
-            String name,
-            Supplier<T> function,
-            Class<T> resultType,
-            StepConfig config,
-            ExecutionManager executionManager,
-            DurableLogger durableLogger,
-            SerDes serDes) {
-        this(operationId, name, function, resultType, null, config, executionManager, durableLogger, serDes);
-    }
-
     public StepOperation(
             String operationId,
             String name,
@@ -62,30 +49,13 @@ public StepOperation(
             ExecutionManager executionManager,
             DurableLogger durableLogger,
             SerDes serDes) {
-        this(operationId, name, function, null, resultTypeToken, config, executionManager, durableLogger, serDes);
-    }
-
-    private StepOperation(
-            String operationId,
-            String name,
-            Supplier<T> function,
-            Class<T> resultType,
-            TypeToken<T> resultTypeToken,
-            StepConfig config,
-            ExecutionManager executionManager,
-            DurableLogger durableLogger,
-            SerDes serDes) {
-        if (resultType == null && resultTypeToken == null) {
+        if (resultTypeToken == null) {
             throw new IllegalArgumentException("Either resultType or resultTypeToken must be provided");
         }
-        if (resultType != null && resultTypeToken != null) {
-            throw new IllegalArgumentException("Cannot provide both resultType and resultTypeToken");
-        }
 
         this.operationId = operationId;
         this.name = name;
         this.function = function;
-        this.resultType = resultType;
         this.resultTypeToken = resultTypeToken;
         this.config = config;
         this.executionManager = executionManager;
@@ -337,12 +307,7 @@ public T get() {
             var stepDetails = op.stepDetails();
             var result = (stepDetails != null) ? stepDetails.result() : null;
 
-            // Use TypeToken if provided, otherwise use Class
-            if (resultTypeToken != null) {
-                return serDes.deserialize(result, resultTypeToken);
-            } else {
-                return serDes.deserialize(result, TypeToken.get(resultType));
-            }
+            return serDes.deserialize(result, resultTypeToken);
         } else {
             // It failed so there's some kind of throwable. If we're using a serDes with
             // type info, deserialize and rethrow the original

sdk/src/test/java/com/amazonaws/lambda/durable/operation/StepOperationTest.java

@@ -5,6 +5,7 @@
 import static org.junit.jupiter.api.Assertions.*;
 import static org.mockito.Mockito.*;
 
+import com.amazonaws.lambda.durable.TypeToken;
 import com.amazonaws.lambda.durable.execution.ExecutionManager;
 import com.amazonaws.lambda.durable.execution.OperationContext;
 import com.amazonaws.lambda.durable.execution.ThreadType;
@@ -26,7 +27,7 @@ void getThrowsIllegalStateExceptionWhenCalledFromStepContext() {
                 "1",
                 "test-step",
                 () -> "result",
-                String.class,
+                TypeToken.get(String.class),
                 null,
                 executionManager,
                 mock(DurableLogger.class),
@@ -58,7 +59,7 @@ void getDoesNotThrowWhenCalledFromHandlerContext() {
                 "1",
                 "test-step",
                 () -> "result",
-                String.class,
+                TypeToken.get(String.class),
                 null,
                 executionManager,
                 mock(DurableLogger.class),