refactor: rename ERROR to CONNECT_ERROR

The meaning is not modified: this packet type is still used by the
server when the connection to a namespace is refused.

Author: darrachequesne

Diff for: lib/client.ts

@@ -91,7 +91,7 @@ export class Client {
       } else {
         debug("creation of namespace %s was denied", name);
         this._packet({
-          type: PacketType.ERROR,
+          type: PacketType.CONNECT_ERROR,
           nsp: name,
           data: "Invalid namespace"
         });

Diff for: lib/socket.ts

@@ -12,8 +12,8 @@ import base64id from "base64id";
 const debug = debugModule("socket.io:socket");
 
 export const RESERVED_EVENTS = new Set([
-  "error",
   "connect",
+  "connect_error",
   "disconnect",
   "disconnecting",
   // EventEmitter reserved events: https://nodejs.org/api/events.html#events_event_newlistener
@@ -316,7 +316,7 @@ export class Socket extends EventEmitter {
         this.ondisconnect();
         break;
 
-      case PacketType.ERROR:
+      case PacketType.CONNECT_ERROR:
         this._onerror(new Error(packet.data));
     }
   }
@@ -438,7 +438,7 @@ export class Socket extends EventEmitter {
    * @private
    */
   _error(err) {
-    this.packet({ type: PacketType.ERROR, data: err });
+    this.packet({ type: PacketType.CONNECT_ERROR, data: err });
   }
 
   /**

Diff for: package.json

@@ -39,7 +39,7 @@
     "debug": "~4.1.0",
     "engine.io": "~4.0.0",
     "socket.io-adapter": "2.0.3-rc2",
-    "socket.io-parser": "4.0.1-rc2"
+    "socket.io-parser": "4.0.1-rc3"
   },
   "devDependencies": {
     "@types/cookie": "^0.4.0",

Diff for: test/socket.io.ts

@@ -1711,8 +1711,8 @@ describe("socket.io", () => {
       srv.listen(() => {
         const socket = client(srv);
         sio.on("connection", s => {
-          expect(() => s.emit("error")).to.throwException(
-            /"error" is a reserved event name/
+          expect(() => s.emit("connect_error")).to.throwException(
+            /"connect_error" is a reserved event name/
           );
           socket.close();
           done();