Goroutine Leak Detector

package main

import (
	"fmt"
	"net/http"
	_ "net/http/pprof"
	"time"
)

// ❌ Keep references alive so GC can't collect the leaked goroutines
var leakedChannels []chan string

// ❌ LEAK: channel is never read — goroutine blocks on send forever
func leakyWriter() {
	ch := make(chan string)
	leakedChannels = append(leakedChannels, ch) // prevents GC from collecting
	go func() {
		ch <- "hello" // blocks forever — nobody reads from ch
	}()
}

// ❌ Keep references alive so GC can't collect the leaked goroutines
var leakedSignals []chan struct{}

// ❌ LEAK: channel is never closed — goroutine waits forever
func leakyListener() {
	ch := make(chan struct{})
	leakedSignals = append(leakedSignals, ch) // prevents GC from collecting
	go func() {
		<-ch // blocks forever — nobody closes or sends to ch
	}()
}

func main() {
	// Start pprof debug server
	go func() {
		http.ListenAndServe("localhost:6060", nil)
	}()

	// Spawn leaks every second
	go func() {
		for {
			leakyWriter()   // ❌ leaks one goroutine per call
			leakyListener() // ❌ leaks one goroutine per call
			time.Sleep(time.Second)
		}
	}()

	fmt.Println("leaking goroutines... visit http://localhost:6060/debug/pprof/goroutine?debug=1")
	fmt.Println("refresh the browser to see the goroutine count grow")
	fmt.Println("press Ctrl+C to stop")

	select {} // block forever
}

goroutine profile: total 59    ← first check
goroutine profile: total 69    ← few seconds later, growing
goroutine profile: total 171   ← keeps growing — you have a leak