separate RSocketError file

Signed-off-by: palani <palam.c@gmail.com>

packages/rsocket-core/src/RSocketError.js

@@ -0,0 +1,26 @@
+/** Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * @flow
+ */
+
+'use strict';
+
+export default class RSocketError extends Error {
+  +errorCode: number;
+  constructor(errorCode: number, message: string) {
+    super(message);
+    this.errorCode = errorCode;
+  }
+}

packages/rsocket-core/src/RSocketMachine.js

@@ -58,6 +58,7 @@ import {
   ResponderLeaseHandler,
   Disposable,
 } from './RSocketLease';
+import RSocketError from './RSocketError';
 
 type Role = 'CLIENT' | 'SERVER';
 
@@ -867,7 +868,10 @@ class RSocketMachineImpl<D, M> implements RSocketMachine<D, M> {
   _sendStreamError(streamId: number, err: Error): void {
     this._subscriptions.delete(streamId);
     this._connection.sendOne({
-      code: err instanceof RSocketError ? err.errorCode : ERROR_CODES.APPLICATION_ERROR,
+      code:
+        err instanceof RSocketError
+          ? err.errorCode
+          : ERROR_CODES.APPLICATION_ERROR,
       flags: 0,
       message: err.message,
       streamId,
@@ -943,11 +947,3 @@ function deserializeMetadataPushPayload<D, M>(
     metadata: serializers.metadata.deserialize(frame.metadata),
   };
 }
-
-export class RSocketError extends Error {
-  +errorCode: number;
-  constructor(errorCode: number, message: string) {
-    super(message);
-    this.errorCode = errorCode;
-  }
-}

packages/rsocket-core/src/index.js

@@ -39,6 +39,10 @@ import RSocketServer from './RSocketServer';
 
 export {RSocketServer};
 
+import RSocketError from './RSocketError';
+
+export {RSocketError};
+
 import RSocketResumableTransport from './RSocketResumableTransport';
 
 export {RSocketResumableTransport};