PLTCONN-3034: Add keepAlive method to Response

lib/response/index.ts

@@ -8,6 +8,7 @@ import { Writable } from 'stream'
 export interface Response<T> {
 	send(output: T): void
 	saveState(state: any): void
+	keepAlive(): void
 }
 
 /**
@@ -35,14 +36,26 @@ export class ResponseStream<T> implements Response<T> {
 	saveState(state: any): void {
 		this._writable.write(new RawResponse(state, ResponseType.State))
 	}
+
+	/**
+	 * Indicates that the commands is still running.
+	 *
+	 * Can be used to avoid a timeout error in the case when a command
+	 * is unable to return responses in a timely manner but is still
+	 * actively processing the command.
+	 */
+	keepAlive(): void {
+		this._writable.write(new RawResponse({}, ResponseType.KeepAlive))
+	}
 }
 
 /**
  * Enum representing different types of responses
  */
 enum ResponseType {
 	Output = 'output',
-	State = 'state'
+	State = 'state',
+	KeepAlive = 'keepAlive'
 }
 
 /**