From 50036a283b120bad69b3db6ba64bc026277ee34e Mon Sep 17 00:00:00 2001
From: Igor Vinokur <ivinokur@redhat.com>
Date: Sat, 11 May 2019 15:25:11 +0300
Subject: [PATCH] Fix "Converting circular structure to JSON" Error

---
 packages/plugin-ext/src/api/rpc-protocol.ts | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/packages/plugin-ext/src/api/rpc-protocol.ts b/packages/plugin-ext/src/api/rpc-protocol.ts
index e9f97f30f526e..4dc3c6b6951bc 100644
--- a/packages/plugin-ext/src/api/rpc-protocol.ts
+++ b/packages/plugin-ext/src/api/rpc-protocol.ts
@@ -318,7 +318,8 @@ class MessageFactory {
         if (messageToSendHostId) {
             prefix = `"hostID":"${messageToSendHostId}",`;
         }
-        return `{${prefix}"type":${MessageType.Request},"id":"${req}","proxyId":"${rpcId}","method":"${method}","args":${JSON.stringify(args, ObjectsTransferrer.replacer)}}`;
+        return `{${prefix}"type":${MessageType.Request},"id":"${req}","proxyId":"${rpcId}","method":"${method}","args":
+        ${JSON.stringify(args, (key, value) => ObjectsTransferrer.replacer([], key, value))}}`;
     }
 
     public static replyOK(req: string, res: any, messageToSendHostId?: string): string {
@@ -329,7 +330,7 @@ class MessageFactory {
         if (typeof res === 'undefined') {
             return `{${prefix}"type":${MessageType.Reply},"id":"${req}"}`;
         }
-        return `{${prefix}"type":${MessageType.Reply},"id":"${req}","res":${JSON.stringify(res, ObjectsTransferrer.replacer)}}`;
+        return `{${prefix}"type":${MessageType.Reply},"id":"${req}","res":${JSON.stringify(res, (key, value) => ObjectsTransferrer.replacer([], key, value))}}`;
     }
 
     public static replyErr(req: string, err: any, messageToSendHostId?: string): string {
@@ -357,7 +358,7 @@ class MessageFactory {
 namespace ObjectsTransferrer {
 
     // tslint:disable-next-line:no-any
-    export function replacer(key: string | undefined, value: any): any {
+    export function replacer(cache: any[], key: string | undefined, value: any): any {
         if (value instanceof URI) {
             return {
                 $type: SerializedObjectType.THEIA_URI,
@@ -387,6 +388,15 @@ namespace ObjectsTransferrer {
                 $type: SerializedObjectType.VSCODE_URI,
                 data: uri.toString()
             } as SerializedObject;
+        } else if (value && typeof value === 'object') {
+            if (cache.indexOf(value) !== -1) {
+                try {
+                    return JSON.parse(JSON.stringify(value));
+                } catch (e) {
+                    return;
+                }
+            }
+            cache.push(value);
         }
 
         return value;