Check if a Go Channel is open or closed

channel_check.go

// An intersting pattern for testing, but you can use the check anywhere
import "testing"

func TestCheckingChannel(t *testing.T) {
  stop := make(chan bool)

  // Testing some fucntion that SHOULD close the channel
  func (stop chan bool) {
    close(chan)
  }(stop)

  // Make sure that the function does close the channel
  _, ok := (<-stop)
  
  // If we can recieve on the channel then it is NOT closed
  if ok {
    t.Error("Channel is not closed")
  }
}

The error will never occur. If the channel isn't closed the function will block forever on line 13.

It would work if you replaced line 13 with the following:

	ok := true
	select {
	case _, ok = <-stop:
	default:
	}

A select with a default clause is a non-blocking read from the channel.

POC on Go Playground

Thanks , you save my day.

❤️