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/bithumb/bithumb.go

@@ -64,7 +64,7 @@ func (b *Bithumb) GetTradablePairs(ctx context.Context) ([]string, error) {
 		return nil, err
 	}
 
-	var currencies []string
+	currencies := make([]string, 0, len(result))
 	for x := range result {
 		currencies = append(currencies, x)
 	}
@@ -703,7 +703,7 @@ func (b *Bithumb) FetchExchangeLimits(ctx context.Context) ([]order.MinMaxLevel,
 		return nil, err
 	}
 
-	var limits []order.MinMaxLevel
+	limits := make([]order.MinMaxLevel, 0, len(ticks))
 	for code, data := range ticks {
 		c := currency.NewCode(code)
 		cp := currency.NewPair(c, currency.KRW)

exchanges/bithumb/bithumb_websocket_test.go

@@ -73,8 +73,7 @@ func TestWsHandleData(t *testing.T) {
 	}
 
 	handled := <-dummy.Websocket.DataHandler
-	_, ok := handled.(*ticker.Price)
-	if !ok {
+	if _, ok := handled.(*ticker.Price); !ok {
 		t.Fatal("unexpected value")
 	}
 

exchanges/bithumb/bithumb_wrapper.go

@@ -336,20 +336,20 @@ func (b *Bithumb) UpdateOrderbook(ctx context.Context, p currency.Pair, assetTyp
 		return book, err
 	}
 
+	book.Bids = make(orderbook.Items, len(orderbookNew.Data.Bids))
 	for i := range orderbookNew.Data.Bids {
-		book.Bids = append(book.Bids,
-			orderbook.Item{
-				Amount: orderbookNew.Data.Bids[i].Quantity,
-				Price:  orderbookNew.Data.Bids[i].Price,
-			})
+		book.Bids[i] = orderbook.Item{
+			Amount: orderbookNew.Data.Bids[i].Quantity,
+			Price:  orderbookNew.Data.Bids[i].Price,
+		}
 	}
 
+	book.Asks = make(orderbook.Items, len(orderbookNew.Data.Asks))
 	for i := range orderbookNew.Data.Asks {
-		book.Asks = append(book.Asks,
-			orderbook.Item{
-				Amount: orderbookNew.Data.Asks[i].Quantity,
-				Price:  orderbookNew.Data.Asks[i].Price,
-			})
+		book.Asks[i] = orderbook.Item{
+			Amount: orderbookNew.Data.Asks[i].Quantity,
+			Price:  orderbookNew.Data.Asks[i].Price,
+		}
 	}
 
 	err = book.Process()
@@ -368,7 +368,7 @@ func (b *Bithumb) UpdateAccountInfo(ctx context.Context, assetType asset.Item) (
 		return info, err
 	}
 
-	var exchangeBalances []account.Balance
+	exchangeBalances := make([]account.Balance, 0, len(bal.Total))
 	for key, totalAmount := range bal.Total {
 		hold, ok := bal.InUse[key]
 		if !ok {
@@ -435,7 +435,7 @@ func (b *Bithumb) GetRecentTrades(ctx context.Context, p currency.Pair, assetTyp
 	if err != nil {
 		return nil, err
 	}
-	var resp []trade.Data
+	resp := make([]trade.Data, len(tradeData.Data))
 	for i := range tradeData.Data {
 		var side order.Side
 		side, err = order.StringToOrderSide(tradeData.Data[i].Type)
@@ -447,7 +447,7 @@ func (b *Bithumb) GetRecentTrades(ctx context.Context, p currency.Pair, assetTyp
 		if err != nil {
 			return nil, err
 		}
-		resp = append(resp, trade.Data{
+		resp[i] = trade.Data{
 			Exchange:     b.Name,
 			CurrencyPair: p,
 			AssetType:    assetType,
@@ -455,7 +455,7 @@ func (b *Bithumb) GetRecentTrades(ctx context.Context, p currency.Pair, assetTyp
 			Price:        tradeData.Data[i].Price,
 			Amount:       tradeData.Data[i].UnitsTraded,
 			Timestamp:    t,
-		})
+		}
 	}
 
 	err = b.AddTradesToBuffer(resp...)

exchanges/bithumb/bithumb_ws_orderbook.go

@@ -26,7 +26,8 @@ const (
 )
 
 func (b *Bithumb) processBooks(updates *WsOrderbooks) error {
-	var bids, asks []orderbook.Item
+	bids := make([]orderbook.Item, 0, len(updates.List))
+	asks := make([]orderbook.Item, 0, len(updates.List))
 	for x := range updates.List {
 		i := orderbook.Item{Price: updates.List[x].Price, Amount: updates.List[x].Quantity}
 		if updates.List[x].OrderSide == "bid" {
@@ -426,17 +427,19 @@ func (b *Bithumb) SeedLocalCache(ctx context.Context, p currency.Pair) error {
 // SeedLocalCacheWithBook seeds the local orderbook cache
 func (b *Bithumb) SeedLocalCacheWithBook(p currency.Pair, o *Orderbook) error {
 	var newOrderBook orderbook.Base
+	newOrderBook.Bids = make(orderbook.Items, len(o.Data.Bids))
 	for i := range o.Data.Bids {
-		newOrderBook.Bids = append(newOrderBook.Bids, orderbook.Item{
+		newOrderBook.Bids[i] = orderbook.Item{
 			Amount: o.Data.Bids[i].Quantity,
 			Price:  o.Data.Bids[i].Price,
-		})
+		}
 	}
+	newOrderBook.Asks = make(orderbook.Items, len(o.Data.Asks))
 	for i := range o.Data.Asks {
-		newOrderBook.Asks = append(newOrderBook.Asks, orderbook.Item{
+		newOrderBook.Asks[i] = orderbook.Item{
 			Amount: o.Data.Asks[i].Quantity,
 			Price:  o.Data.Asks[i].Price,
-		})
+		}
 	}
 
 	newOrderBook.Pair = p