package acme import ( "testing" "time" ) func TestWaitForTimeout(t *testing.T) { c := make(chan error) go func() { err := WaitFor(3*time.Second, 1*time.Second, func() (bool, error) { return false, nil }) c <- err }() timeout := time.After(4 * time.Second) select { case <-timeout: t.Fatal("timeout exceeded") case err := <-c: if err == nil { t.Errorf("expected timeout error; got %v", err) } } }