diff --git a/packages/durabletask-js/src/worker/index.ts b/packages/durabletask-js/src/worker/index.ts
index 36f8c0b..c3311e2 100644
--- a/packages/durabletask-js/src/worker/index.ts
+++ b/packages/durabletask-js/src/worker/index.ts
@@ -49,6 +49,23 @@ export function getMethodNameForAction(action: pb.OrchestratorAction): string {
       return "callSubOrchestrator";
     case pb.OrchestratorAction.OrchestratoractiontypeCase.COMPLETEORCHESTRATION:
       return "completeOrchestration";
+    case pb.OrchestratorAction.OrchestratoractiontypeCase.SENDEVENT:
+      return "sendEvent";
+    case pb.OrchestratorAction.OrchestratoractiontypeCase.SENDENTITYMESSAGE:
+      switch (action.getSendentitymessage()?.getEntitymessagetypeCase()) {
+        case pb.SendEntityMessageAction.EntitymessagetypeCase.ENTITYOPERATIONCALLED:
+          return "callEntity";
+        case pb.SendEntityMessageAction.EntitymessagetypeCase.ENTITYOPERATIONSIGNALED:
+          return "signalEntity";
+        case pb.SendEntityMessageAction.EntitymessagetypeCase.ENTITYLOCKREQUESTED:
+          return "lockEntities";
+        case pb.SendEntityMessageAction.EntitymessagetypeCase.ENTITYUNLOCKSENT:
+          return "lockRelease";
+        default:
+          return "sendEntityMessage";
+      }
+    case pb.OrchestratorAction.OrchestratoractiontypeCase.TERMINATEORCHESTRATION:
+      return "terminateOrchestration";
     default:
       throw new Error(`Unknown action type: ${actionType}`);
   }
diff --git a/packages/durabletask-js/test/worker-helpers.spec.ts b/packages/durabletask-js/test/worker-helpers.spec.ts
new file mode 100644
index 0000000..6050bf8
--- /dev/null
+++ b/packages/durabletask-js/test/worker-helpers.spec.ts
@@ -0,0 +1,237 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+import * as pb from "../src/proto/orchestrator_service_pb";
+import {
+  getMethodNameForAction,
+  getWrongActionTypeError,
+  getNonDeterminismError,
+  getNewEventSummary,
+  getActionSummary,
+  isSuspendable,
+} from "../src/worker/index";
+import { NonDeterminismError } from "../src/task/exception/non-determinism-error";
+
+/**
+ * Creates an OrchestratorAction with the given action type set.
+ */
+function createActionWithType(
+  actionCase: pb.OrchestratorAction.OrchestratoractiontypeCase,
+): pb.OrchestratorAction {
+  const action = new pb.OrchestratorAction();
+
+  switch (actionCase) {
+    case pb.OrchestratorAction.OrchestratoractiontypeCase.SCHEDULETASK:
+      action.setScheduletask(new pb.ScheduleTaskAction());
+      break;
+    case pb.OrchestratorAction.OrchestratoractiontypeCase.CREATETIMER:
+      action.setCreatetimer(new pb.CreateTimerAction());
+      break;
+    case pb.OrchestratorAction.OrchestratoractiontypeCase.CREATESUBORCHESTRATION:
+      action.setCreatesuborchestration(new pb.CreateSubOrchestrationAction());
+      break;
+    case pb.OrchestratorAction.OrchestratoractiontypeCase.COMPLETEORCHESTRATION:
+      action.setCompleteorchestration(new pb.CompleteOrchestrationAction());
+      break;
+    case pb.OrchestratorAction.OrchestratoractiontypeCase.SENDEVENT:
+      action.setSendevent(new pb.SendEventAction());
+      break;
+    case pb.OrchestratorAction.OrchestratoractiontypeCase.SENDENTITYMESSAGE:
+      action.setSendentitymessage(new pb.SendEntityMessageAction());
+      break;
+    case pb.OrchestratorAction.OrchestratoractiontypeCase.TERMINATEORCHESTRATION:
+      action.setTerminateorchestration(new pb.TerminateOrchestrationAction());
+      break;
+  }
+
+  return action;
+}
+
+function createSendEntityMessageAction(
+  configure: (message: pb.SendEntityMessageAction) => void,
+): pb.OrchestratorAction {
+  const sendEntityMessage = new pb.SendEntityMessageAction();
+  configure(sendEntityMessage);
+
+  const action = new pb.OrchestratorAction();
+  action.setSendentitymessage(sendEntityMessage);
+  return action;
+}
+
+describe("Worker helper functions", () => {
+  describe("getMethodNameForAction", () => {
+    it("should return 'callActivity' for SCHEDULETASK", () => {
+      const action = createActionWithType(pb.OrchestratorAction.OrchestratoractiontypeCase.SCHEDULETASK);
+      expect(getMethodNameForAction(action)).toBe("callActivity");
+    });
+
+    it("should return 'createTimer' for CREATETIMER", () => {
+      const action = createActionWithType(pb.OrchestratorAction.OrchestratoractiontypeCase.CREATETIMER);
+      expect(getMethodNameForAction(action)).toBe("createTimer");
+    });
+
+    it("should return 'callSubOrchestrator' for CREATESUBORCHESTRATION", () => {
+      const action = createActionWithType(pb.OrchestratorAction.OrchestratoractiontypeCase.CREATESUBORCHESTRATION);
+      expect(getMethodNameForAction(action)).toBe("callSubOrchestrator");
+    });
+
+    it("should return 'completeOrchestration' for COMPLETEORCHESTRATION", () => {
+      const action = createActionWithType(pb.OrchestratorAction.OrchestratoractiontypeCase.COMPLETEORCHESTRATION);
+      expect(getMethodNameForAction(action)).toBe("completeOrchestration");
+    });
+
+    it("should return 'sendEvent' for SENDEVENT", () => {
+      const action = createActionWithType(pb.OrchestratorAction.OrchestratoractiontypeCase.SENDEVENT);
+      expect(getMethodNameForAction(action)).toBe("sendEvent");
+    });
+
+    it("should return 'sendEntityMessage' for SENDENTITYMESSAGE with unknown subtype", () => {
+      const action = createActionWithType(pb.OrchestratorAction.OrchestratoractiontypeCase.SENDENTITYMESSAGE);
+      expect(getMethodNameForAction(action)).toBe("sendEntityMessage");
+    });
+
+    it("should return 'callEntity' for SENDENTITYMESSAGE entity operation call", () => {
+      const action = createSendEntityMessageAction((message) => {
+        message.setEntityoperationcalled(new pb.EntityOperationCalledEvent());
+      });
+      expect(getMethodNameForAction(action)).toBe("callEntity");
+    });
+
+    it("should return 'signalEntity' for SENDENTITYMESSAGE entity operation signal", () => {
+      const action = createSendEntityMessageAction((message) => {
+        message.setEntityoperationsignaled(new pb.EntityOperationSignaledEvent());
+      });
+      expect(getMethodNameForAction(action)).toBe("signalEntity");
+    });
+
+    it("should return 'lockEntities' for SENDENTITYMESSAGE entity lock request", () => {
+      const action = createSendEntityMessageAction((message) => {
+        message.setEntitylockrequested(new pb.EntityLockRequestedEvent());
+      });
+      expect(getMethodNameForAction(action)).toBe("lockEntities");
+    });
+
+    it("should return 'lockRelease' for SENDENTITYMESSAGE entity unlock sent", () => {
+      const action = createSendEntityMessageAction((message) => {
+        message.setEntityunlocksent(new pb.EntityUnlockSentEvent());
+      });
+      expect(getMethodNameForAction(action)).toBe("lockRelease");
+    });
+
+    it("should return 'terminateOrchestration' for TERMINATEORCHESTRATION", () => {
+      const action = createActionWithType(pb.OrchestratorAction.OrchestratoractiontypeCase.TERMINATEORCHESTRATION);
+      expect(getMethodNameForAction(action)).toBe("terminateOrchestration");
+    });
+
+    it("should throw for ORCHESTRATORACTIONTYPE_NOT_SET", () => {
+      const action = new pb.OrchestratorAction();
+      expect(() => getMethodNameForAction(action)).toThrow("Unknown action type: 0");
+    });
+  });
+
+  describe("getWrongActionTypeError", () => {
+    it("should return a NonDeterminismError with expected and actual method names", () => {
+      const action = createActionWithType(pb.OrchestratorAction.OrchestratoractiontypeCase.SENDEVENT);
+      const error = getWrongActionTypeError(5, "callActivity", action);
+
+      expect(error).toBeInstanceOf(NonDeterminismError);
+      expect(error.message).toContain("callActivity");
+      expect(error.message).toContain("sendEvent");
+      expect(error.message).toContain("ID=5");
+    });
+
+    it("should return a NonDeterminismError for entity message action", () => {
+      const action = createSendEntityMessageAction((message) => {
+        message.setEntityoperationcalled(new pb.EntityOperationCalledEvent());
+      });
+      const error = getWrongActionTypeError(3, "createTimer", action);
+
+      expect(error).toBeInstanceOf(NonDeterminismError);
+      expect(error.message).toContain("createTimer");
+      expect(error.message).toContain("callEntity");
+      expect(error.message).toContain("ID=3");
+    });
+
+    it("should return a NonDeterminismError for terminate orchestration action", () => {
+      const action = createActionWithType(pb.OrchestratorAction.OrchestratoractiontypeCase.TERMINATEORCHESTRATION);
+      const error = getWrongActionTypeError(7, "callSubOrchestrator", action);
+
+      expect(error).toBeInstanceOf(NonDeterminismError);
+      expect(error.message).toContain("callSubOrchestrator");
+      expect(error.message).toContain("terminateOrchestration");
+      expect(error.message).toContain("ID=7");
+    });
+  });
+
+  describe("getNonDeterminismError", () => {
+    it("should return a NonDeterminismError with task ID and action name", () => {
+      const error = getNonDeterminismError(42, "callActivity");
+
+      expect(error).toBeInstanceOf(NonDeterminismError);
+      expect(error.message).toContain("callActivity");
+      expect(error.message).toContain("ID=42");
+    });
+  });
+
+  describe("getNewEventSummary", () => {
+    it("should return '[]' for empty events", () => {
+      expect(getNewEventSummary([])).toBe("[]");
+    });
+
+    it("should return single event type name for one event", () => {
+      const event = new pb.HistoryEvent();
+      event.setTaskcompleted(new pb.TaskCompletedEvent());
+      const result = getNewEventSummary([event]);
+      expect(result).toBe("[TASKCOMPLETED]");
+    });
+
+    it("should return grouped counts for multiple events", () => {
+      const event1 = new pb.HistoryEvent();
+      event1.setTaskcompleted(new pb.TaskCompletedEvent());
+      const event2 = new pb.HistoryEvent();
+      event2.setTaskcompleted(new pb.TaskCompletedEvent());
+      const result = getNewEventSummary([event1, event2]);
+      expect(result).toContain("TASKCOMPLETED=2");
+    });
+  });
+
+  describe("getActionSummary", () => {
+    it("should return '[]' for empty actions", () => {
+      expect(getActionSummary([])).toBe("[]");
+    });
+
+    it("should return action type name for single action", () => {
+      const action = createActionWithType(pb.OrchestratorAction.OrchestratoractiontypeCase.SCHEDULETASK);
+      const result = getActionSummary([action]);
+      expect(result).toBe("SCHEDULETASK");
+    });
+
+    it("should return grouped counts for multiple actions", () => {
+      const action1 = createActionWithType(pb.OrchestratorAction.OrchestratoractiontypeCase.SCHEDULETASK);
+      const action2 = createActionWithType(pb.OrchestratorAction.OrchestratoractiontypeCase.CREATETIMER);
+      const result = getActionSummary([action1, action2]);
+      expect(result).toContain("SCHEDULETASK=1");
+      expect(result).toContain("CREATETIMER=1");
+    });
+  });
+
+  describe("isSuspendable", () => {
+    it("should return false for EXECUTIONRESUMED", () => {
+      const event = new pb.HistoryEvent();
+      event.setExecutionresumed(new pb.ExecutionResumedEvent());
+      expect(isSuspendable(event)).toBe(false);
+    });
+
+    it("should return false for EXECUTIONTERMINATED", () => {
+      const event = new pb.HistoryEvent();
+      event.setExecutionterminated(new pb.ExecutionTerminatedEvent());
+      expect(isSuspendable(event)).toBe(false);
+    });
+
+    it("should return true for other events like TASKCOMPLETED", () => {
+      const event = new pb.HistoryEvent();
+      event.setTaskcompleted(new pb.TaskCompletedEvent());
+      expect(isSuspendable(event)).toBe(true);
+    });
+  });
+});