feat(Rest): expose https.Agent options (#6177)

Co-authored-by: Antonio Román <kyradiscord@gmail.com>

src/rest/APIRequest.js

@@ -5,7 +5,7 @@ const FormData = require('@discordjs/form-data');
 const fetch = require('node-fetch');
 const { UserAgent } = require('../util/Constants');
 
-const agent = new https.Agent({ keepAlive: true });
+let agent = null;
 
 class APIRequest {
   constructor(rest, method, path, options) {
@@ -30,6 +30,8 @@ class APIRequest {
   }
 
   make() {
+    agent ??= new https.Agent({ ...this.client.options.http.agent, keepAlive: true });
+
     const API =
       this.options.versioned === false
         ? this.client.options.http.api

src/util/Options.js

@@ -80,10 +80,18 @@
  * sent in the initial guild member list, must be between 50 and 250
  */
 
+/**
+ * HTTPS Agent options.
+ * @typedef {Object} AgentOptions
+ * @see {@link https://nodejs.org/api/https.html#https_class_https_agent}
+ * @see {@link https://nodejs.org/api/http.html#http_new_agent_options}
+ */
+
 /**
  * HTTP options
  * @typedef {Object} HTTPOptions
  * @property {number} [version=9] API version to use
+ * @property {AgentOptions} [agent={}] HTTPS Agent options
  * @property {string} [api='https://discord.com/api'] Base url of the API
  * @property {string} [cdn='https://cdn.discordapp.com'] Base url of the CDN
  * @property {string} [invite='https://discord.gg'] Base url of invites
@@ -127,6 +135,7 @@ class Options extends null {
         version: 9,
       },
       http: {
+        agent: {},
         version: 9,
         api: 'https://discord.com/api',
         cdn: 'https://cdn.discordapp.com',

typings/index.d.ts

@@ -47,6 +47,7 @@ import {
   Snowflake,
 } from 'discord-api-types/v9';
 import { EventEmitter } from 'events';
+import { AgentOptions } from 'https';
 import { Stream } from 'stream';
 import { MessagePort, Worker } from 'worker_threads';
 import * as WebSocket from 'ws';
@@ -3893,6 +3894,7 @@ export interface HTTPErrorData {
 }
 
 export interface HTTPOptions {
+  agent?: Omit<AgentOptions, 'keepAlive'>;
   api?: string;
   version?: number;
   host?: string;