new tcp error

Author: hnasr

03-pending-callbacks/031-tcp-error-loopback.js

@@ -0,0 +1,55 @@
+//example where pending callbacks are scheduled in a different phase. 
+const net = require('net');
+const fs = require(`fs`);
+ 
+console.log(`START`);
+// Define the IP and port
+//change the host to a none existant port host, 
+//the ECONNREFUSED will be queued in the pending callbacks phase output will be 
+/*START
+END
+time out
+Connection error: connect ECONNREFUSED 127.0.0.1:80
+Connection closed
+readFileCallback hello world
+*/
+//but if you change it to a valid ip/port say google's 
+//the output will be 
+/*
+START
+END
+time out
+readFileCallback hello world
+Connected to server at 142.250.188.23:80
+*/
+
+ 
+
+// Create a client
+const clientFail = new net.Socket();
+const clientSuccess = new net.Socket();
+
+// Connect to the server (fails)
+clientFail.connect(9999,'127.0.0.1', () => {
+    console.log(`Connected to server at ${'192.168.4.21'}:${9999}`);
+});
+// Connect to the server that exists (this is example.com)
+clientSuccess.connect(80, '93.184.215.14', () => {
+    console.log(`Connected to server at ${'93.184.215.14'}:${80}`);
+});
+
+// Handle errors
+clientFail.on('error', (err) => {
+    console.error(`Connection error: ${err.message}`);
+});
+// Handle errors
+clientSuccess.on('error', (err) => {
+    console.error(`Connection error: ${err.message}`);
+});
+
+ 
+//slow down the initial phase
+for (let i = 1; i <= 500000000; i++);
+//after the loop ends and initial phase is done, we enter the poll phase and actually read the file (no callbacks ready)
+console.log(`END`);
+