fix: check if the channel is closed before returning ws.result to prevent panic

rpc/ws/accountSubscribe.go

@@ -85,7 +85,10 @@ type AccountSubscription struct {
 
 func (sw *AccountSubscription) Recv() (*AccountResult, error) {
 	select {
-	case d := <-sw.sub.stream:
+	case d, ok := <-sw.sub.stream:
+		if !ok {
+			return nil, ErrSubscriptionClosed
+		}
 		return d.(*AccountResult), nil
 	case err := <-sw.sub.err:
 		return nil, err

rpc/ws/blockSubscribe.go

@@ -150,7 +150,10 @@ type BlockSubscription struct {
 
 func (sw *BlockSubscription) Recv() (*BlockResult, error) {
 	select {
-	case d := <-sw.sub.stream:
+	case d, ok := <-sw.sub.stream:
+		if !ok {
+			return nil, ErrSubscriptionClosed
+		}
 		return d.(*BlockResult), nil
 	case err := <-sw.sub.err:
 		return nil, err

rpc/ws/client.go

@@ -19,6 +19,7 @@ package ws
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -32,6 +33,8 @@ import (
 	"go.uber.org/zap"
 )
 
+var ErrSubscriptionClosed = errors.New("subscription closed")
+
 type result interface{}
 
 type Client struct {

rpc/ws/logsSubscribe.go

@@ -109,7 +109,10 @@ type LogSubscription struct {
 
 func (sw *LogSubscription) Recv() (*LogResult, error) {
 	select {
-	case d := <-sw.sub.stream:
+	case d, ok := <-sw.sub.stream:
+		if !ok {
+			return nil, ErrSubscriptionClosed
+		}
 		return d.(*LogResult), nil
 	case err := <-sw.sub.err:
 		return nil, err

rpc/ws/programSubscribe.go

@@ -88,7 +88,10 @@ type ProgramSubscription struct {
 
 func (sw *ProgramSubscription) Recv() (*ProgramResult, error) {
 	select {
-	case d := <-sw.sub.stream:
+	case d, ok := <-sw.sub.stream:
+		if !ok {
+			return nil, ErrSubscriptionClosed
+		}
 		return d.(*ProgramResult), nil
 	case err := <-sw.sub.err:
 		return nil, err

rpc/ws/rootSubscribe.go

@@ -44,7 +44,10 @@ type RootSubscription struct {
 
 func (sw *RootSubscription) Recv() (*RootResult, error) {
 	select {
-	case d := <-sw.sub.stream:
+	case d, ok := <-sw.sub.stream:
+		if !ok {
+			return nil, ErrSubscriptionClosed
+		}
 		return d.(*RootResult), nil
 	case err := <-sw.sub.err:
 		return nil, err

rpc/ws/signatureSubscribe.go

@@ -69,7 +69,10 @@ type SignatureSubscription struct {
 
 func (sw *SignatureSubscription) Recv() (*SignatureResult, error) {
 	select {
-	case d := <-sw.sub.stream:
+	case d, ok := <-sw.sub.stream:
+		if !ok {
+			return nil, ErrSubscriptionClosed
+		}
 		return d.(*SignatureResult), nil
 	case err := <-sw.sub.err:
 		return nil, err

rpc/ws/slotSubscribe.go

@@ -47,7 +47,10 @@ type SlotSubscription struct {
 
 func (sw *SlotSubscription) Recv() (*SlotResult, error) {
 	select {
-	case d := <-sw.sub.stream:
+	case d, ok := <-sw.sub.stream:
+		if !ok {
+			return nil, ErrSubscriptionClosed
+		}
 		return d.(*SlotResult), nil
 	case err := <-sw.sub.err:
 		return nil, err

rpc/ws/slotsUpdatesSubscribe.go

@@ -79,7 +79,10 @@ type SlotsUpdatesSubscription struct {
 
 func (sw *SlotsUpdatesSubscription) Recv() (*SlotsUpdatesResult, error) {
 	select {
-	case d := <-sw.sub.stream:
+	case d, ok := <-sw.sub.stream:
+		if !ok {
+			return nil, ErrSubscriptionClosed
+		}
 		return d.(*SlotsUpdatesResult), nil
 	case err := <-sw.sub.err:
 		return nil, err

rpc/ws/voteSubscribe.go

@@ -61,7 +61,10 @@ type VoteSubscription struct {
 
 func (sw *VoteSubscription) Recv() (*VoteResult, error) {
 	select {
-	case d := <-sw.sub.stream:
+	case d, ok := <-sw.sub.stream:
+		if !ok {
+			return nil, ErrSubscriptionClosed
+		}
 		return d.(*VoteResult), nil
 	case err := <-sw.sub.err:
 		return nil, err