refactor: refact FanIn func in channel.go

concurrency/channel.go

@@ -97,32 +97,29 @@ func (c *Channel) Take(ctx context.Context, valueStream <-chan any, number int)
 
 // FanIn merge multiple channels into one channel
 func (c *Channel) FanIn(ctx context.Context, channels ...<-chan any) <-chan any {
+	out := make(chan any)
+
+	go func() {
 		var wg sync.WaitGroup
-	multiplexedStream := make(chan any)
+		wg.Add(len(channels))
 
-	multiplex := func(c <-chan any) {
+		for _, c := range channels {
+			go func(c <-chan any) {
 				defer wg.Done()
-
+				for v := range c {
-		for i := range c {
 					select {
 					case <-ctx.Done():
 						return
-			case multiplexedStream <- i:
+					case out <- v:
 					}
 				}
+			}(c)
 		}
-
-	wg.Add(len(channels))
-	for _, c := range channels {
-		go multiplex(c)
-	}
-
-	go func() {
 		wg.Wait()
-		close(multiplexedStream)
+		close(out)
 	}()
 
-	return multiplexedStream
+	return out
 }
 
 // Tee split one chanel into two channels