add errors and cast check (#468)

* refactor conn.go method(serveRead)

* fixed issue#444 golangci-lint error

* try my best to avoid ignoring error(exclude test file)

* update README.md,change to check error

* update README.md,change to check error

* revert golangci-lint

* revert golangci-lint code

* revert golangci-lint code

* add error msg

* fixed by comments

* fixed by comments

Co-authored-by: ralphchen <Wwkkvikthh123>

Author: ralfbawg

engineio/README.md

@@ -72,4 +72,4 @@ func main() {
 
 ## License
 
-The 3-clause BSD License  - see LICENSE for more details
+The 3-clause BSD License  - see [LICENSE](https://opensource.org/licenses/BSD-3-Clause) for more details

engineio/client.go

@@ -1,6 +1,7 @@
 package engineio
 
 import (
+	"fmt"
 	"io"
 	"net"
 	"net/http"
@@ -66,10 +67,14 @@ func (c *client) NextReader() (session.FrameType, io.ReadCloser, error) {
 
 		switch pt {
 		case packet.PONG:
-			c.conn.SetReadDeadline(time.Now().Add(c.params.PingInterval + c.params.PingTimeout))
+			if err = c.conn.SetReadDeadline(time.Now().Add(c.params.PingInterval + c.params.PingTimeout)); err != nil {
+				return 0, nil, err
+			}
+
 		case packet.CLOSE:
 			c.Close()
 			return 0, nil, io.EOF
+
 		case packet.MESSAGE:
 			return session.FrameType(ft), r, nil
 		}
@@ -116,6 +121,9 @@ func (c *client) serve() {
 		if err := w.Close(); err != nil {
 			return
 		}
-		c.conn.SetWriteDeadline(time.Now().Add(c.params.PingInterval + c.params.PingTimeout))
+
+		if err = c.conn.SetWriteDeadline(time.Now().Add(c.params.PingInterval + c.params.PingTimeout)); err != nil {
+			fmt.Printf("set writer's deadline error,msg:%s\n", err.Error())
+		}
 	}
 }

engineio/transport/polling/server.go

@@ -2,6 +2,7 @@ package polling
 
 import (
 	"bytes"
+	"fmt"
 	"html/template"
 	"net"
 	"net/http"
@@ -64,7 +65,7 @@ func (c *serverConn) SetHeaders(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("X-XSS-Protection", "0")
 	}
 
-	//just in case the default behaviour gets changed and it has to handle an origin check
+	// just in case the default behaviour gets changed and it has to handle an origin check
 	checkOrigin := Default.CheckOrigin
 	if c.transport.CheckOrigin != nil {
 		checkOrigin = c.transport.CheckOrigin
@@ -136,6 +137,9 @@ func (c *serverConn) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		}
 
 		_, err = w.Write([]byte("ok"))
+		if err != nil {
+			fmt.Printf("ack post err=%s\n", err.Error())
+		}
 
 	default:
 		http.Error(w, "invalid method", http.StatusBadRequest)

namespace_conn.go

@@ -132,5 +132,4 @@ func (nc *namespaceConn) dispatch(header parser.Header) {
 			return
 		}
 	}
-	return
 }

redis_broadcast.go

@@ -129,8 +129,13 @@ func newRedisBroadcast(nsp string, adapter *RedisAdapterOptions) (*redisBroadcas
 	bc.resChannel = bc.prefix + "-response#" + bc.nsp
 	bc.requests = make(map[string]interface{})
 
-	bc.sub.PSubscribe(bc.prefix + "#" + bc.nsp + "#*")
-	bc.sub.Subscribe(bc.reqChannel, bc.resChannel)
+	if err = bc.sub.PSubscribe(bc.prefix + "#" + bc.nsp + "#*"); err != nil {
+		return nil, err
+	}
+
+	if err = bc.sub.Subscribe(bc.reqChannel, bc.resChannel); err != nil {
+		return nil, err
+	}
 
 	go func() {
 		for {
@@ -144,7 +149,10 @@ func newRedisBroadcast(nsp string, adapter *RedisAdapterOptions) (*redisBroadcas
 					break
 				}
 
-				bc.onMessage(m.Channel, m.Data)
+				err = bc.onMessage(m.Channel, m.Data)
+				if err != nil {
+					return
+				}
 			case redis.Subscription:
 				if m.Count == 0 {
 					return
@@ -172,9 +180,13 @@ func (bc *redisBroadcast) AllRooms() []string {
 	req.done = make(chan bool, 1)
 
 	bc.requests[req.RequestID] = &req
-	bc.pub.Conn.Do("PUBLISH", bc.reqChannel, reqJSON)
+	_, err := bc.pub.Conn.Do("PUBLISH", bc.reqChannel, reqJSON)
+	if err != nil {
+		return []string{} // if error occurred,return empty
+	}
 
 	<-req.done
+
 	rooms := make([]string, 0, len(req.rooms))
 	for room := range req.rooms {
 		rooms = append(rooms, room)
@@ -338,6 +350,9 @@ func (bc *redisBroadcast) onMessage(channel string, msg []byte) error {
 	}
 
 	event, ok := opts[1].(string)
+	if !ok {
+		return errors.New("invalid event")
+	}
 
 	if room != "" {
 		bc.send(room, event, args...)
@@ -355,19 +370,20 @@ func (bc *redisBroadcast) getNumSub(channel string) (int, error) {
 		return 0, err
 	}
 
-	var numSub64 int64
-	numSub64 = rs.([]interface{})[1].(int64)
-	return int(numSub64), nil
+	numSub64, ok := rs.([]interface{})[1].(int)
+	if !ok {
+		return 0, errors.New("redis reply cast to int error")
+	}
+	return numSub64, nil
 }
 
 // Handle request from redis channel.
 func (bc *redisBroadcast) onRequest(msg []byte) {
 	var req map[string]string
-	err := json.Unmarshal(msg, &req)
-	if err != nil {
+
+	if err := json.Unmarshal(msg, &req); err != nil {
 		return
 	}
-	// log.Println("on request:", req)
 
 	var res interface{}
 	switch req["RequestType"] {
@@ -417,7 +433,6 @@ func (bc *redisBroadcast) onResponse(msg []byte) {
 		return
 	}
 
-	// log.Println("on resp:", res)
 	switch res["RequestType"] {
 	case roomLenReqType:
 		roomLenReq := req.(*roomLenRequest)