CI: Fix golangci-lint linter issues, add prealloc linter and bump version depends for Go 1.18 (#915)

* Bump CI versions

* Specifically set go version as 1.17.x bumps it to 1.18

* Another

* Adjust AppVeyor

* Part 1 of linter issues

* Part 2

* Fix various linters and improvements

* Part 3

* Finishing touches

* Tests and EqualFold

* Fix nitterinos plus bonus requester jobs bump for exchanges with large number of tests

* Fix nitterinos and bump golangci-lint timeout for AppVeyor

* Address nits, ensure all books are returned on err due to syncer regression

* Fix the wiggins

* Fix duplication

* Fix nitterinos

exchanges/stream/stream_match.go

@@ -17,8 +17,8 @@ func NewMatch() *Match {
 // connections. Stream systems fan in all incoming payloads to one routine for
 // processing.
 type Match struct {
-	m map[interface{}]chan []byte
-	sync.Mutex
+	m  map[interface{}]chan []byte
+	mu sync.Mutex
 }
 
 // Incoming matches with request, disregarding the returned payload
@@ -29,8 +29,8 @@ func (m *Match) Incoming(signature interface{}) bool {
 // IncomingWithData matches with requests and takes in the returned payload, to
 // be processed outside of a stream processing routine
 func (m *Match) IncomingWithData(signature interface{}, data []byte) bool {
-	m.Lock()
-	defer m.Unlock()
+	m.mu.Lock()
+	defer m.mu.Unlock()
 	ch, ok := m.m[signature]
 	if ok {
 		select {
@@ -47,15 +47,15 @@ func (m *Match) IncomingWithData(signature interface{}, data []byte) bool {
 // Sets the signature response channel for incoming data
 func (m *Match) set(signature interface{}) (matcher, error) {
 	var ch chan []byte
-	m.Lock()
+	m.mu.Lock()
 	if _, ok := m.m[signature]; ok {
-		m.Unlock()
+		m.mu.Unlock()
 		return matcher{}, errors.New("signature collision")
 	}
 	// This is buffered so we don't need to wait for receiver.
 	ch = make(chan []byte, 1)
 	m.m[signature] = ch
-	m.Unlock()
+	m.mu.Unlock()
 
 	return matcher{
 		C:   ch,
@@ -73,8 +73,8 @@ type matcher struct {
 
 // Cleanup closes underlying channel and deletes signature from map
 func (m *matcher) Cleanup() {
-	m.m.Lock()
+	m.m.mu.Lock()
 	close(m.C)
 	delete(m.m.m, m.sig)
-	m.m.Unlock()
+	m.m.mu.Unlock()
 }

exchanges/stream/websocket_connection.go

@@ -6,7 +6,7 @@ import (
 	"compress/gzip"
 	"crypto/rand"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"math/big"
 	"net"
 	"net/http"
@@ -156,7 +156,7 @@ func (w *WebsocketConnection) SetupPingHandler(handler PingHandler) {
 				time.Now().Add(handler.Delay))
 			if err == websocket.ErrCloseSent {
 				return nil
-			} else if e, ok := err.(net.Error); ok && e.Temporary() {
+			} else if e, ok := err.(net.Error); ok && e.Timeout() {
 				return nil
 			}
 			return err
@@ -260,7 +260,7 @@ func (w *WebsocketConnection) parseBinaryResponse(resp []byte) ([]byte, error) {
 		if err != nil {
 			return standardMessage, err
 		}
-		standardMessage, err = ioutil.ReadAll(gReader)
+		standardMessage, err = io.ReadAll(gReader)
 		if err != nil {
 			return standardMessage, err
 		}
@@ -270,7 +270,7 @@ func (w *WebsocketConnection) parseBinaryResponse(resp []byte) ([]byte, error) {
 		}
 	} else {
 		reader := flate.NewReader(bytes.NewReader(resp))
-		standardMessage, err = ioutil.ReadAll(reader)
+		standardMessage, err = io.ReadAll(reader)
 		if err != nil {
 			return standardMessage, err
 		}

exchanges/stream/websocket_test.go

@@ -305,7 +305,10 @@ func TestConnectionMessageErrors(t *testing.T) {
 	ws.ReadMessageErrors <- errors.New("errorText")
 	select {
 	case err := <-ws.ToRoutine:
-		if err.(error).Error() != "errorText" {
+		errText, ok := err.(error)
+		if !ok {
+			t.Error("unable to type assert error")
+		} else if errText.Error() != "errorText" {
 			t.Errorf("Expected 'errorText', received %v", err)
 		}
 	case <-timer.C:
@@ -1045,12 +1048,12 @@ type GenSubs struct {
 
 // generateSubs default subs created from the enabled pairs list
 func (g *GenSubs) generateSubs() ([]ChannelSubscription, error) {
-	var superduperchannelsubs []ChannelSubscription
+	superduperchannelsubs := make([]ChannelSubscription, len(g.EnabledPairs))
 	for i := range g.EnabledPairs {
-		superduperchannelsubs = append(superduperchannelsubs, ChannelSubscription{
+		superduperchannelsubs[i] = ChannelSubscription{
 			Channel:  "TEST:" + strconv.FormatInt(int64(i), 10),
 			Currency: g.EnabledPairs[i],
-		})
+		}
 	}
 	return superduperchannelsubs, nil
 }