add ability to control if the gateway should identify or not

Allows you to add a `gateway.onIdentifyCheck = () => true` function to control if the gateway should identify during automatic instances, like when an invalid session event is received or on a hello event.

Author: cakedan

package.json

@@ -1,6 +1,6 @@
 {
   "name": "detritus-client-socket",
-  "version": "0.5.0",
+  "version": "0.5.1",
   "description": "A TypeScript NodeJS library to interact with Discord's Gateway",
   "main": "lib/index.js",
   "types": "lib/index.d.ts",

src/constants.ts

@@ -1,6 +1,6 @@
 export const Package = Object.freeze({
   URL: 'https://github.com/detritusjs/client-socket',
-  VERSION: '0.5.0',
+  VERSION: '0.5.1',
 });
 
 function normalize(object: {[key: string]: any}) {

src/gateway.ts

@@ -81,6 +81,7 @@ export interface SocketOptions {
   reconnectMax?: number,
   shardCount?: number,
   shardId?: number,
+  onIdentifyCheck?: () => boolean | Promise<boolean>,
 }
 
 export class Socket extends EventSpewer {
@@ -126,6 +127,8 @@ export class Socket extends EventSpewer {
   url: URL | null = null;
   userId: null | string = null;
 
+  onIdentifyCheck?(): boolean | Promise<boolean>;
+
   constructor(
     token: string,
     options: SocketOptions = {},
@@ -155,6 +158,8 @@ export class Socket extends EventSpewer {
     this.shardId = <number> options.shardId;
     this.token = token;
 
+    this.onIdentifyCheck = options.onIdentifyCheck || this.onIdentifyCheck;
+
     if (options.presence) {
       this.presence = Object.assign({}, defaultPresence, options.presence);
     }
@@ -490,7 +495,7 @@ export class Socket extends EventSpewer {
         if (this.sessionId) {
           this.resume();
         } else {
-          this.identify();
+          this.identifyTry();
         }
       }; break;
       case GatewayOpCodes.INVALID_SESSION: {
@@ -501,7 +506,7 @@ export class Socket extends EventSpewer {
           } else {
             this.sequence = 0;
             this.sessionId = null;
-            this.identify();
+            this.identifyTry();
           }
         }, Math.floor(Math.random() * 5 + 1) * 1000);
       }; break;
@@ -733,6 +738,12 @@ export class Socket extends EventSpewer {
     }, true);
   }
 
+  async identifyTry(): Promise<void> {
+    if (!this.onIdentifyCheck || (await Promise.resolve(this.onIdentifyCheck()))) {
+      this.identify();
+    }
+  }
+
   resume(): void {
     this.resuming = true;
     const data = this.getResumeData();