fix: use Node.js https agent when endpoint uses https (#12692)

web3.js/src/agent-manager.js

@@ -1,19 +1,31 @@
 // @flow
 
-import {Agent} from 'http';
+import http from 'http';
+import https from 'https';
 
 export const DESTROY_TIMEOUT_MS = 5000;
 
 export class AgentManager {
-  _agent: Agent = AgentManager._newAgent();
+  _agent: http.Agent | https.Agent;
   _activeRequests = 0;
   _destroyTimeout: TimeoutID | null = null;
+  _useHttps: boolean;
 
-  static _newAgent(): Agent {
-    return new Agent({keepAlive: true, maxSockets: 25});
+  static _newAgent(useHttps: boolean): http.Agent | https.Agent {
+    const options = {keepAlive: true, maxSockets: 25};
+    if (useHttps) {
+      return new https.Agent(options);
+    } else {
+      return new http.Agent(options);
+    }
   }
 
-  requestStart(): Agent {
+  constructor(useHttps?: boolean) {
+    this._useHttps = useHttps === true;
+    this._agent = AgentManager._newAgent(this._useHttps);
+  }
+
+  requestStart(): http.Agent | https.Agent {
     // $FlowExpectedError - Don't manage agents in the browser
     if (process.browser) return;
 
@@ -31,7 +43,7 @@ export class AgentManager {
     if (this._activeRequests === 0 && this._destroyTimeout === null) {
       this._destroyTimeout = setTimeout(() => {
         this._agent.destroy();
-        this._agent = AgentManager._newAgent();
+        this._agent = AgentManager._newAgent(this._useHttps);
       }, DESTROY_TIMEOUT_MS);
     }
   }

web3.js/src/connection.js

@@ -505,8 +505,8 @@ type ConfirmedBlock = {
   }>,
 };
 
-function createRpcRequest(url): RpcRequest {
-  const agentManager = new AgentManager();
+function createRpcRequest(url: string, useHttps: boolean): RpcRequest {
+  const agentManager = new AgentManager(useHttps);
   const server = jayson(async (request, callback) => {
     const agent = agentManager.requestStart();
     const options = {
@@ -1453,8 +1453,9 @@ export class Connection {
    */
   constructor(endpoint: string, commitment: ?Commitment) {
     let url = urlParse(endpoint);
+    const useHttps = url.protocol === 'https:';
 
-    this._rpcRequest = createRpcRequest(url.href);
+    this._rpcRequest = createRpcRequest(url.href, useHttps);
     this._commitment = commitment;
     this._blockhashInfo = {
       recentBlockhash: null,
@@ -1463,7 +1464,7 @@ export class Connection {
       simulatedSignatures: [],
     };
 
-    url.protocol = url.protocol === 'https:' ? 'wss:' : 'ws:';
+    url.protocol = useHttps ? 'wss:' : 'ws:';
     url.host = '';
     // Only shift the port by +1 as a convention for ws(s) only if given endpoint
     // is explictly specifying the endpoint port (HTTP-based RPC), assuming