fix: fsnotify watcher panics when closing (#3399)

Author: wlynxg

os/gfsnotify/gfsnotify_watcher.go

@@ -106,11 +106,11 @@ func (w *Watcher) addWithCallbackFunc(name, path string, callbackFunc func(event
 
 // Close closes the watcher.
 func (w *Watcher) Close() {
-	w.events.Close()
+	close(w.closeChan)
 	if err := w.watcher.Close(); err != nil {
 		intlog.Errorf(context.TODO(), `%+v`, err)
 	}
-	close(w.closeChan)
+	w.events.Close()
 }
 
 // Remove removes monitor and all callbacks associated with the `path` recursively.

os/gfsnotify/gfsnotify_watcher_loop.go

@@ -8,6 +8,7 @@ package gfsnotify
 
 import (
 	"context"
+
 	"github.com/gogf/gf/v2/errors/gcode"
 	"github.com/gogf/gf/v2/errors/gerror"
 
@@ -25,7 +26,10 @@ func (w *Watcher) watchLoop() {
 				return
 
 			// Event listening.
-			case ev := <-w.watcher.Events:
+			case ev, ok := <-w.watcher.Events:
+				if !ok {
+					return
+				}
 				// Filter the repeated event in custom duration.
 				_, err := w.cache.SetIfNotExist(
 					context.Background(),

os/gfsnotify/gfsnotify_z_unit_test.go

@@ -218,3 +218,23 @@ func TestWatcher_WatchFolderWithoutRecursively(t *testing.T) {
 		t.Assert(array.Len(), 1)
 	})
 }
+
+func TestWatcher_WatchClose(t *testing.T) {
+	gtest.C(t, func(t *gtest.T) {
+		var (
+			err     error
+			dirPath = gfile.Temp(gtime.TimestampNanoStr())
+			watcher *gfsnotify.Watcher
+		)
+
+		err = gfile.Mkdir(dirPath)
+		t.AssertNil(err)
+
+		watcher, err = gfsnotify.New()
+		t.AssertNil(err)
+		t.AssertNE(watcher, nil)
+
+		time.Sleep(time.Millisecond * 100)
+		watcher.Close()
+	})
+}