From 735372ab3ccf63fc155b52e955b2c69d499e347a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=B8=96=E7=95=8C?= <i@sekai.icu>
Date: Thu, 11 Aug 2022 23:20:14 +0800
Subject: [PATCH] Fix close subscriber

---
 common/observable/subscriber.go | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/common/observable/subscriber.go b/common/observable/subscriber.go
index 195c43b..032ec77 100644
--- a/common/observable/subscriber.go
+++ b/common/observable/subscriber.go
@@ -1,5 +1,9 @@
 package observable
 
+import (
+	"os"
+)
+
 type Subscription[T any] <-chan T
 
 type Subscriber[T any] struct {
@@ -20,6 +24,11 @@ func (s *Subscriber[T]) Emit(item T) {
 }
 
 func (s *Subscriber[T]) Close() error {
+	select {
+	case <-s.done:
+		return os.ErrClosed
+	default:
+	}
 	close(s.done)
 	return nil
 }