fix: use errors method to check equivalence (#925)

Signed-off-by: Chris Gianelloni <[email protected]>

Author: wolf31o2

protocol/chainsync/client.go

@@ -722,7 +722,7 @@ func (c *Client) handleRollForward(msgGeneric protocol.Message) error {
 		}
 	}
 	if callbackErr != nil {
-		if callbackErr == StopSyncProcessError {
+		if errors.Is(callbackErr, StopSyncProcessError) {
 			// Signal that we're cancelling the sync
 			c.readyForNextBlockChan <- false
 			return nil
@@ -751,7 +751,7 @@ func (c *Client) handleRollBackward(msg protocol.Message) error {
 		}
 		// Call the user callback function
 		if callbackErr := c.config.RollBackwardFunc(c.callbackContext, msgRollBackward.Point, msgRollBackward.Tip); callbackErr != nil {
-			if callbackErr == StopSyncProcessError {
+			if errors.Is(callbackErr, StopSyncProcessError) {
 				// Signal that we're cancelling the sync
 				c.readyForNextBlockChan <- false
 				return nil

protocol/chainsync/client_test.go

@@ -1,4 +1,4 @@
-// Copyright 2024 Blink Labs Software
+// Copyright 2025 Blink Labs Software
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -15,6 +15,7 @@
 package chainsync_test
 
 import (
+	"errors"
 	"fmt"
 	"reflect"
 	"testing"
@@ -127,7 +128,7 @@ func TestIntersectNotFound(t *testing.T) {
 			if err == nil {
 				t.Fatalf("did not receive expected error")
 			}
-			if err != chainsync.IntersectNotFoundError {
+			if !errors.Is(err, chainsync.IntersectNotFoundError) {
 				t.Fatalf(
 					"did not receive expected error\n  got:    %s\n  wanted: %s",
 					err,

protocol/chainsync/server.go

@@ -203,7 +203,7 @@ func (s *Server) handleFindIntersect(msg protocol.Message) error {
 		msgFindIntersect.Points,
 	)
 	if err != nil {
-		if err == IntersectNotFoundError {
+		if errors.Is(err, IntersectNotFoundError) {
 			msgResp := NewMsgIntersectNotFound(tip)
 			if err := s.SendMessage(msgResp); err != nil {
 				return err

protocol/protocol.go

@@ -363,7 +363,7 @@ func (p *Protocol) recvLoop() {
 		tmpMsg := []cbor.RawMessage{}
 		numBytesRead, err := cbor.Decode(recvBuffer.Bytes(), &tmpMsg)
 		if err != nil {
-			if err == io.ErrUnexpectedEOF && recvBuffer.Len() > 0 {
+			if errors.Is(err, io.ErrUnexpectedEOF) && recvBuffer.Len() > 0 {
 				// This is probably a multi-part message, so we wait until we get more of the message
 				// before trying to process it
 				p.recvReadyChan <- true