Replace a zero-length, non-nil slice with a nil slice (#299)

* Replace a zero-length, non-nil slice with a nil slice

* Update codelingo.yaml

codelingo.yaml

@@ -6,7 +6,7 @@ tenets:
   - import: codelingo/effective-go/single-method-interface-name
   - import: codelingo/effective-go/underscores-in-name
   - import: codelingo/effective-go/unnecessary-else
- 
+  - import: codelingo/code-review-comments/declare-empty-slice 
   # Overwrite one tenet with custom logic
   # - import: codelingo/effective-go/comment-first-word-when-empty
   - name: comment-first-word-when-empty

common/common_test.go

@@ -715,7 +715,7 @@ func TestExtractPort(t *testing.T) {
 
 func TestOutputCSV(t *testing.T) {
 	path := "../testdata/dump"
-	data := [][]string{}
+	var data [][]string
 	rowOne := []string{"Appended", "to", "two", "dimensional", "array"}
 	rowTwo := []string{"Appended", "to", "two", "dimensional", "array", "two"}
 	data = append(data, rowOne, rowTwo)

exchanges/binance/binance.go

@@ -239,7 +239,7 @@ func (b *Binance) GetOrderBook(obd OrderBookDataRequestParams) (OrderBook, error
 // GetRecentTrades returns recent trade activity
 // limit: Up to 500 results returned
 func (b *Binance) GetRecentTrades(rtr RecentTradeRequestParams) ([]RecentTrade, error) {
-	resp := []RecentTrade{}
+	var resp []RecentTrade
 
 	params := url.Values{}
 	params.Set("symbol", common.StringToUpper(rtr.Symbol))
@@ -256,7 +256,7 @@ func (b *Binance) GetRecentTrades(rtr RecentTradeRequestParams) ([]RecentTrade,
 // limit: Optional. Default 500; max 1000.
 // fromID:
 func (b *Binance) GetHistoricalTrades(symbol string, limit int, fromID int64) ([]HistoricalTrade, error) {
-	resp := []HistoricalTrade{}
+	var resp []HistoricalTrade
 
 	if err := b.CheckLimit(limit); err != nil {
 		return resp, err
@@ -277,7 +277,7 @@ func (b *Binance) GetHistoricalTrades(symbol string, limit int, fromID int64) ([
 // symbol: string of currency pair
 // limit: Optional. Default 500; max 1000.
 func (b *Binance) GetAggregatedTrades(symbol string, limit int) ([]AggregatedTrade, error) {
-	resp := []AggregatedTrade{}
+	var resp []AggregatedTrade
 
 	if err := b.CheckLimit(limit); err != nil {
 		return resp, err

exchanges/bitfinex/bitfinex.go

@@ -310,7 +310,7 @@ func (b *Bitfinex) GetTickersV2(symbols string) ([]Tickersv2, error) {
 
 // GetStats returns various statistics about the requested pair
 func (b *Bitfinex) GetStats(symbol string) ([]Stat, error) {
-	response := []Stat{}
+	var response []Stat
 	path := fmt.Sprint(b.APIUrl + bitfinexAPIVersion + bitfinexStats + symbol)
 
 	return response, b.SendHTTPRequest(path, &response, b.Verbose)
@@ -402,7 +402,7 @@ func (b *Bitfinex) GetOrderbookV2(symbol, precision string, values url.Values) (
 // Values can contain limit amounts for the number of trades returned - Example
 // "limit_trades" = 1000
 func (b *Bitfinex) GetTrades(currencyPair string, values url.Values) ([]TradeStructure, error) {
-	response := []TradeStructure{}
+	var response []TradeStructure
 	path := common.EncodeURLValues(
 		b.APIUrl+bitfinexAPIVersion+bitfinexTrades+currencyPair,
 		values,
@@ -480,7 +480,7 @@ func (b *Bitfinex) GetLendbook(symbol string, values url.Values) (Lendbook, erro
 // over time
 // Symbol - example "USD"
 func (b *Bitfinex) GetLends(symbol string, values url.Values) ([]Lends, error) {
-	response := []Lends{}
+	var response []Lends
 	path := common.EncodeURLValues(b.APIUrl+bitfinexAPIVersion+bitfinexLends+symbol,
 		values)
 
@@ -489,7 +489,7 @@ func (b *Bitfinex) GetLends(symbol string, values url.Values) ([]Lends, error) {
 
 // GetSymbols returns the available currency pairs on the exchange
 func (b *Bitfinex) GetSymbols() ([]string, error) {
-	products := []string{}
+	var products []string
 	path := fmt.Sprint(b.APIUrl + bitfinexAPIVersion + bitfinexSymbols)
 
 	return products, b.SendHTTPRequest(path, &products, b.Verbose)
@@ -497,7 +497,7 @@ func (b *Bitfinex) GetSymbols() ([]string, error) {
 
 // GetSymbolsDetails a list of valid symbol IDs and the pair details
 func (b *Bitfinex) GetSymbolsDetails() ([]SymbolDetails, error) {
-	response := []SymbolDetails{}
+	var response []SymbolDetails
 	path := fmt.Sprint(b.APIUrl + bitfinexAPIVersion + bitfinexSymbolsDetails)
 
 	return response, b.SendHTTPRequest(path, &response, b.Verbose)
@@ -560,7 +560,7 @@ func (b *Bitfinex) GetKeyPermissions() (KeyPermissions, error) {
 
 // GetMarginInfo shows your trading wallet information for margin trading
 func (b *Bitfinex) GetMarginInfo() ([]MarginInfo, error) {
-	response := []MarginInfo{}
+	var response []MarginInfo
 
 	return response,
 		b.SendAuthenticatedHTTPRequest(http.MethodPost,
@@ -569,7 +569,7 @@ func (b *Bitfinex) GetMarginInfo() ([]MarginInfo, error) {
 
 // GetAccountBalance returns full wallet balance information
 func (b *Bitfinex) GetAccountBalance() ([]Balance, error) {
-	response := []Balance{}
+	var response []Balance
 
 	return response,
 		b.SendAuthenticatedHTTPRequest(http.MethodPost,
@@ -582,7 +582,7 @@ func (b *Bitfinex) GetAccountBalance() ([]Balance, error) {
 // WalletFrom - example "exchange"
 // WalletTo -  example "deposit"
 func (b *Bitfinex) WalletTransfer(amount float64, currency, walletFrom, walletTo string) ([]WalletTransfer, error) {
-	response := []WalletTransfer{}
+	var response []WalletTransfer
 	req := make(map[string]interface{})
 	req["amount"] = amount
 	req["currency"] = currency
@@ -599,7 +599,7 @@ func (b *Bitfinex) WalletTransfer(amount float64, currency, walletFrom, walletTo
 // WithdrawCryptocurrency requests a withdrawal from one of your wallets.
 // For FIAT, use WithdrawFIAT
 func (b *Bitfinex) WithdrawCryptocurrency(withdrawType, wallet, address, paymentID string, amount float64, c currency.Code) ([]Withdrawal, error) {
-	response := []Withdrawal{}
+	var response []Withdrawal
 	req := make(map[string]interface{})
 	req["withdraw_type"] = withdrawType
 	req["walletselected"] = wallet
@@ -618,7 +618,7 @@ func (b *Bitfinex) WithdrawCryptocurrency(withdrawType, wallet, address, payment
 
 // WithdrawFIAT requests a withdrawal from a designated fiat wallet
 func (b *Bitfinex) WithdrawFIAT(withdrawalType, walletType string, withdrawRequest *exchange.WithdrawRequest) ([]Withdrawal, error) {
-	response := []Withdrawal{}
+	var response []Withdrawal
 	req := make(map[string]interface{})
 
 	req["withdraw_type"] = withdrawalType
@@ -787,7 +787,7 @@ func (b *Bitfinex) GetOpenOrders() ([]Order, error) {
 
 // GetActivePositions returns an array of active positions
 func (b *Bitfinex) GetActivePositions() ([]Position, error) {
-	response := []Position{}
+	var response []Position
 
 	return response,
 		b.SendAuthenticatedHTTPRequest(http.MethodPost,
@@ -811,7 +811,7 @@ func (b *Bitfinex) ClaimPosition(positionID int) (Position, error) {
 
 // GetBalanceHistory returns balance history for the account
 func (b *Bitfinex) GetBalanceHistory(symbol string, timeSince, timeUntil time.Time, limit int, wallet string) ([]BalanceHistory, error) {
-	response := []BalanceHistory{}
+	var response []BalanceHistory
 	req := make(map[string]interface{})
 	req["currency"] = symbol
 
@@ -837,7 +837,7 @@ func (b *Bitfinex) GetBalanceHistory(symbol string, timeSince, timeUntil time.Ti
 
 // GetMovementHistory returns an array of past deposits and withdrawals
 func (b *Bitfinex) GetMovementHistory(symbol, method string, timeSince, timeUntil time.Time, limit int) ([]MovementHistory, error) {
-	response := []MovementHistory{}
+	var response []MovementHistory
 	req := make(map[string]interface{})
 	req["currency"] = symbol
 
@@ -863,7 +863,7 @@ func (b *Bitfinex) GetMovementHistory(symbol, method string, timeSince, timeUnti
 
 // GetTradeHistory returns past executed trades
 func (b *Bitfinex) GetTradeHistory(currencyPair string, timestamp, until time.Time, limit, reverse int) ([]TradeHistory, error) {
-	response := []TradeHistory{}
+	var response []TradeHistory
 	req := make(map[string]interface{})
 	req["currency"] = currencyPair
 	req["timestamp"] = timestamp
@@ -931,7 +931,7 @@ func (b *Bitfinex) GetOfferStatus(offerID int64) (Offer, error) {
 
 // GetActiveCredits returns all available credits
 func (b *Bitfinex) GetActiveCredits() ([]Offer, error) {
-	response := []Offer{}
+	var response []Offer
 
 	return response,
 		b.SendAuthenticatedHTTPRequest(http.MethodPost,
@@ -942,7 +942,7 @@ func (b *Bitfinex) GetActiveCredits() ([]Offer, error) {
 
 // GetActiveOffers returns all current active offers
 func (b *Bitfinex) GetActiveOffers() ([]Offer, error) {
-	response := []Offer{}
+	var response []Offer
 
 	return response,
 		b.SendAuthenticatedHTTPRequest(http.MethodPost,
@@ -953,7 +953,7 @@ func (b *Bitfinex) GetActiveOffers() ([]Offer, error) {
 
 // GetActiveMarginFunding returns an array of active margin funds
 func (b *Bitfinex) GetActiveMarginFunding() ([]MarginFunds, error) {
-	response := []MarginFunds{}
+	var response []MarginFunds
 
 	return response,
 		b.SendAuthenticatedHTTPRequest(http.MethodPost,
@@ -965,7 +965,7 @@ func (b *Bitfinex) GetActiveMarginFunding() ([]MarginFunds, error) {
 // GetUnusedMarginFunds returns an array of funding borrowed but not currently
 // used
 func (b *Bitfinex) GetUnusedMarginFunds() ([]MarginFunds, error) {
-	response := []MarginFunds{}
+	var response []MarginFunds
 
 	return response,
 		b.SendAuthenticatedHTTPRequest(http.MethodPost,
@@ -977,7 +977,7 @@ func (b *Bitfinex) GetUnusedMarginFunds() ([]MarginFunds, error) {
 // GetMarginTotalTakenFunds returns an array of active funding used in a
 // position
 func (b *Bitfinex) GetMarginTotalTakenFunds() ([]MarginTotalTakenFunds, error) {
-	response := []MarginTotalTakenFunds{}
+	var response []MarginTotalTakenFunds
 
 	return response,
 		b.SendAuthenticatedHTTPRequest(http.MethodPost,

exchanges/bitfinex/bitfinex_websocket.go

@@ -286,7 +286,7 @@ func (b *Bitfinex) WsDataHandler() {
 
 					switch chanInfo.Channel {
 					case "book":
-						newOrderbook := []WebsocketBook{}
+						var newOrderbook []WebsocketBook
 						switch len(chanData) {
 						case 2:
 							data := chanData[1].([]interface{})
@@ -340,7 +340,7 @@ func (b *Bitfinex) WsDataHandler() {
 					case "account":
 						switch chanData[1].(string) {
 						case bitfinexWebsocketPositionSnapshot:
-							positionSnapshot := []WebsocketPosition{}
+							var positionSnapshot []WebsocketPosition
 							data := chanData[2].([]interface{})
 							for _, x := range data {
 								y := x.([]interface{})
@@ -374,7 +374,7 @@ func (b *Bitfinex) WsDataHandler() {
 
 						case bitfinexWebsocketWalletSnapshot:
 							data := chanData[2].([]interface{})
-							walletSnapshot := []WebsocketWallet{}
+							var walletSnapshot []WebsocketWallet
 							for _, x := range data {
 								y := x.([]interface{})
 								walletSnapshot = append(walletSnapshot,
@@ -398,7 +398,7 @@ func (b *Bitfinex) WsDataHandler() {
 							b.Websocket.DataHandler <- wallet
 
 						case bitfinexWebsocketOrderSnapshot:
-							orderSnapshot := []WebsocketOrder{}
+							var orderSnapshot []WebsocketOrder
 							data := chanData[2].([]interface{})
 							for _, x := range data {
 								y := x.([]interface{})
@@ -447,7 +447,7 @@ func (b *Bitfinex) WsDataHandler() {
 						}
 
 					case "trades":
-						trades := []WebsocketTrade{}
+						var trades []WebsocketTrade
 						switch len(chanData) {
 						case 2:
 							data := chanData[1].([]interface{})

exchanges/bitstamp/bitstamp.go

@@ -316,7 +316,7 @@ func (b *Bitstamp) GetTradingPairs() ([]TradingPair, error) {
 // value paramater ["time"] = "minute", "hour", "day" will collate your
 // response into time intervals. Implementation of value in test code.
 func (b *Bitstamp) GetTransactions(currencyPair string, values url.Values) ([]Transactions, error) {
-	transactions := []Transactions{}
+	var transactions []Transactions
 	path := common.EncodeURLValues(
 		fmt.Sprintf(
 			"%s/v%s/%s/%s/",
@@ -361,7 +361,7 @@ func (b *Bitstamp) GetUserTransactions(currencyPair string) ([]UserTransactions,
 		Fee     float64     `json:"fee,string"`
 		OrderID int64       `json:"order_id"`
 	}
-	response := []Response{}
+	var response []Response
 
 	if currencyPair != "" {
 		if err := b.SendAuthenticatedHTTPRequest(bitstampAPIUserTransactions, true, url.Values{}, &response); err != nil {
@@ -373,7 +373,7 @@ func (b *Bitstamp) GetUserTransactions(currencyPair string) ([]UserTransactions,
 		}
 	}
 
-	transactions := []UserTransactions{}
+	var transactions []UserTransactions
 
 	for _, y := range response {
 		tx := UserTransactions{}
@@ -416,7 +416,7 @@ func (b *Bitstamp) GetUserTransactions(currencyPair string) ([]UserTransactions,
 
 // GetOpenOrders returns all open orders on the exchange
 func (b *Bitstamp) GetOpenOrders(currencyPair string) ([]Order, error) {
-	resp := []Order{}
+	var resp []Order
 	path := fmt.Sprintf(
 		"%s/%s", bitstampAPIOpenOrders, common.StringToLower(currencyPair),
 	)
@@ -478,7 +478,7 @@ func (b *Bitstamp) PlaceOrder(currencyPair string, price, amount float64, buy, m
 // timedelta - positive integer with max value 50000000 which returns requests
 // from number of seconds ago to now.
 func (b *Bitstamp) GetWithdrawalRequests(timedelta int64) ([]WithdrawalRequests, error) {
-	resp := []WithdrawalRequests{}
+	var resp []WithdrawalRequests
 	if timedelta > 50000000 || timedelta < 0 {
 		return resp, errors.New("time delta exceeded, max: 50000000 min: 0")
 	}
@@ -613,7 +613,7 @@ func (b *Bitstamp) GetCryptoDepositAddress(crypto currency.Code) (string, error)
 
 // GetUnconfirmedBitcoinDeposits returns unconfirmed transactions
 func (b *Bitstamp) GetUnconfirmedBitcoinDeposits() ([]UnconfirmedBTCTransactions, error) {
-	response := []UnconfirmedBTCTransactions{}
+	var response []UnconfirmedBTCTransactions
 
 	return response,
 		b.SendAuthenticatedHTTPRequest(bitstampAPIUnconfirmedBitcoin, false, nil, &response)

exchanges/btcmarkets/btcmarkets.go

@@ -165,7 +165,7 @@ func (b *BTCMarkets) GetOrderbook(firstPair, secondPair string) (Orderbook, erro
 // symbol - example "btc" or "ltc"
 // values - optional paramater "since" example values.Set(since, "59868345231")
 func (b *BTCMarkets) GetTrades(firstPair, secondPair string, values url.Values) ([]Trade, error) {
-	trades := []Trade{}
+	var trades []Trade
 	path := common.EncodeURLValues(fmt.Sprintf("%s/market/%s/%s/trades",
 		b.APIUrl, common.StringToUpper(firstPair),
 		common.StringToUpper(secondPair)), values)
@@ -352,7 +352,7 @@ func (b *BTCMarkets) GetOrderDetail(orderID []int64) ([]Order, error) {
 
 // GetAccountBalance returns the full account balance
 func (b *BTCMarkets) GetAccountBalance() ([]AccountBalance, error) {
-	balance := []AccountBalance{}
+	var balance []AccountBalance
 
 	err := b.SendAuthenticatedRequest(http.MethodGet, btcMarketsAccountBalance, nil, &balance)
 	if err != nil {

exchanges/coinbasepro/coinbasepro.go

@@ -144,7 +144,7 @@ func (c *CoinbasePro) Setup(exch *config.ExchangeConfig) {
 // GetProducts returns supported currency pairs on the exchange with specific
 // information about the pair
 func (c *CoinbasePro) GetProducts() ([]Product, error) {
-	products := []Product{}
+	var products []Product
 
 	return products, c.SendHTTPRequest(c.APIUrl+coinbaseproProducts, &products)
 }
@@ -233,7 +233,7 @@ func (c *CoinbasePro) GetTicker(currencyPair string) (Ticker, error) {
 // GetTrades listd the latest trades for a product
 // currencyPair - example "BTC-USD"
 func (c *CoinbasePro) GetTrades(currencyPair string) ([]Trade, error) {
-	trades := []Trade{}
+	var trades []Trade
 	path := fmt.Sprintf(
 		"%s/%s/%s", c.APIUrl+coinbaseproProducts, currencyPair, coinbaseproTrades)
 
@@ -244,7 +244,7 @@ func (c *CoinbasePro) GetTrades(currencyPair string) ([]Trade, error) {
 // grouped buckets based on requested granularity.
 func (c *CoinbasePro) GetHistoricRates(currencyPair string, start, end, granularity int64) ([]History, error) {
 	var resp [][]interface{}
-	history := []History{}
+	var history []History
 	values := url.Values{}
 
 	if start > 0 {
@@ -300,7 +300,7 @@ func (c *CoinbasePro) GetStats(currencyPair string) (Stats, error) {
 // GetCurrencies returns a list of supported currency on the exchange
 // Warning: Not all currencies may be currently in use for tradinc.
 func (c *CoinbasePro) GetCurrencies() ([]Currency, error) {
-	currencies := []Currency{}
+	var currencies []Currency
 
 	return currencies, c.SendHTTPRequest(c.APIUrl+coinbaseproCurrencies, &currencies)
 }
@@ -314,7 +314,7 @@ func (c *CoinbasePro) GetServerTime() (ServerTime, error) {
 
 // GetAccounts returns a list of trading accounts associated with the APIKEYS
 func (c *CoinbasePro) GetAccounts() ([]AccountResponse, error) {
-	resp := []AccountResponse{}
+	var resp []AccountResponse
 
 	return resp,
 		c.SendAuthenticatedHTTPRequest(http.MethodGet, coinbaseproAccounts, nil, &resp)
@@ -333,7 +333,7 @@ func (c *CoinbasePro) GetAccount(accountID string) (AccountResponse, error) {
 // increases or decreases your account balance. Items are paginated and sorted
 // latest first.
 func (c *CoinbasePro) GetAccountHistory(accountID string) ([]AccountLedgerResponse, error) {
-	resp := []AccountLedgerResponse{}
+	var resp []AccountLedgerResponse
 	path := fmt.Sprintf("%s/%s/%s", coinbaseproAccounts, accountID, coinbaseproLedger)
 
 	return resp, c.SendAuthenticatedHTTPRequest(http.MethodGet, path, nil, &resp)
@@ -344,7 +344,7 @@ func (c *CoinbasePro) GetAccountHistory(accountID string) ([]AccountLedgerRespon
 // is updated. If an order is canceled, any remaining hold is removed. For a
 // withdraw, once it is completed, the hold is removed.
 func (c *CoinbasePro) GetHolds(accountID string) ([]AccountHolds, error) {
-	resp := []AccountHolds{}
+	var resp []AccountHolds
 	path := fmt.Sprintf("%s/%s/%s", coinbaseproAccounts, accountID, coinbaseproHolds)
 
 	return resp, c.SendAuthenticatedHTTPRequest(http.MethodGet, path, nil, &resp)
@@ -514,7 +514,7 @@ func (c *CoinbasePro) CancelAllExistingOrders(currencyPair string) ([]string, er
 // status - can be a range of "open", "pending", "done" or "active"
 // currencyPair - [optional] for example "BTC-USD"
 func (c *CoinbasePro) GetOrders(status []string, currencyPair string) ([]GeneralizedOrderResponse, error) {
-	resp := []GeneralizedOrderResponse{}
+	var resp []GeneralizedOrderResponse
 	params := url.Values{}
 
 	for _, individualStatus := range status {
@@ -541,7 +541,7 @@ func (c *CoinbasePro) GetOrder(orderID string) (GeneralizedOrderResponse, error)
 
 // GetFills returns a list of recent fills
 func (c *CoinbasePro) GetFills(orderID, currencyPair string) ([]FillResponse, error) {
-	resp := []FillResponse{}
+	var resp []FillResponse
 	params := url.Values{}
 
 	if orderID != "" {
@@ -566,7 +566,7 @@ func (c *CoinbasePro) GetFills(orderID, currencyPair string) ([]FillResponse, er
 //
 // status - "outstanding", "settled", or "rejected"
 func (c *CoinbasePro) GetFundingRecords(status string) ([]Funding, error) {
-	resp := []Funding{}
+	var resp []Funding
 	params := url.Values{}
 	params.Set("status", status)
 
@@ -636,7 +636,7 @@ func (c *CoinbasePro) ClosePosition(repayOnly bool) (AccountOverview, error) {
 
 // GetPayMethods returns a full list of payment methods
 func (c *CoinbasePro) GetPayMethods() ([]PaymentMethod, error) {
-	resp := []PaymentMethod{}
+	var resp []PaymentMethod
 
 	return resp,
 		c.SendAuthenticatedHTTPRequest(http.MethodGet, coinbaseproPaymentMethod, nil, &resp)
@@ -729,7 +729,7 @@ func (c *CoinbasePro) WithdrawCrypto(amount float64, currency, cryptoAddress str
 
 // GetCoinbaseAccounts returns a list of coinbase accounts
 func (c *CoinbasePro) GetCoinbaseAccounts() ([]CoinbaseAccounts, error) {
-	resp := []CoinbaseAccounts{}
+	var resp []CoinbaseAccounts
 
 	return resp,
 		c.SendAuthenticatedHTTPRequest(http.MethodGet, coinbaseproCoinbaseAccounts, nil, &resp)
@@ -784,7 +784,7 @@ func (c *CoinbasePro) GetReportStatus(reportID string) (Report, error) {
 // GetTrailingVolume this request will return your 30-day trailing volume for
 // all products.
 func (c *CoinbasePro) GetTrailingVolume() ([]Volume, error) {
-	resp := []Volume{}
+	var resp []Volume
 
 	return resp,
 		c.SendAuthenticatedHTTPRequest(http.MethodGet, coinbaseproTrailingVolume, nil, &resp)

exchanges/coinbasepro/coinbasepro_websocket.go

@@ -22,7 +22,7 @@ const (
 // WebsocketSubscriber subscribes to websocket channels with respect to enabled
 // currencies
 func (c *CoinbasePro) WebsocketSubscriber() error {
-	currencies := []string{}
+	var currencies []string
 	for _, x := range c.EnabledPairs.Strings() {
 		currency := x[0:3] + "-" + x[3:]
 		currencies = append(currencies, currency)

exchanges/coinbasepro/coinbasepro_wrapper.go

@@ -36,7 +36,7 @@ func (c *CoinbasePro) Run() {
 	if err != nil {
 		log.Errorf("%s Failed to get available products.\n", c.GetName())
 	} else {
-		currencies := []string{}
+		var currencies []string
 		for _, x := range exchangeProducts {
 			if x.ID != "BTC" && x.ID != "USD" && x.ID != "GBP" {
 				currencies = append(currencies, x.ID[0:3]+x.ID[4:])

exchanges/coinut/coinut.go

@@ -252,7 +252,7 @@ func (c *COINUT) CancelOrders(orders []CancelOrders) (CancelOrdersResponse, erro
 		OrderID      int `json:"order_id"`
 	}
 
-	entries := []CancelOrders{}
+	var entries []CancelOrders
 	entries = append(entries, orders...)
 	params["entries"] = entries
 

exchanges/coinut/coinut_wrapper.go

@@ -39,7 +39,7 @@ func (c *COINUT) Run() {
 		return
 	}
 
-	currencies := []string{}
+	var currencies []string
 	c.InstrumentMap = make(map[string]int)
 	for x, y := range exchangeProducts.Instruments {
 		c.InstrumentMap[x] = y[0].InstID

exchanges/exchange.go

@@ -896,7 +896,7 @@ func (e *Base) SupportsWithdrawPermissions(permissions uint32) bool {
 
 // FormatWithdrawPermissions will return each of the exchange's compatible withdrawal methods in readable form
 func (e *Base) FormatWithdrawPermissions() string {
-	services := []string{}
+	var services []string
 	for i := 0; i < 32; i++ {
 		var check uint32 = 1 << uint32(i)
 		if e.GetWithdrawPermissions()&check != 0 {

exchanges/exchange_websocket.go

@@ -645,7 +645,7 @@ func (w *Websocket) SupportsFunctionality(f uint32) bool {
 // FormatFunctionality will return each of the websocket connection compatible
 // stream methods as a string
 func (w *Websocket) FormatFunctionality() string {
-	functionality := []string{}
+	var functionality []string
 	for i := 0; i < 32; i++ {
 		var check uint32 = 1 << uint32(i)
 		if w.GetFunctionality()&check != 0 {

exchanges/exmo/exmo.go

@@ -154,7 +154,7 @@ func (e *EXMO) GetPairSettings() (map[string]PairSettings, error) {
 
 // GetCurrency returns a list of currencies
 func (e *EXMO) GetCurrency() ([]string, error) {
-	result := []string{}
+	var result []string
 	urlPath := fmt.Sprintf("%s/v%s/%s", e.APIUrl, exmoAPIVersion, exmoCurrency)
 	return result, e.SendHTTPRequest(urlPath, &result)
 }

exchanges/gateio/gateio.go

@@ -292,7 +292,7 @@ func (g *Gateio) GetSpotKline(arg KlinesRequestParams) ([]*KLineResponse, error)
 	}
 
 	rawKlineDatasString, _ := json.Marshal(rawKlines["data"].([]interface{}))
-	rawKlineDatas := [][]interface{}{}
+	var rawKlineDatas [][]interface{}
 	if err := json.Unmarshal(rawKlineDatasString, &rawKlineDatas); err != nil {
 		return nil, fmt.Errorf("rawKlines unmarshal failed. Err: %s", err)
 	}

exchanges/gemini/gemini.go

@@ -178,7 +178,7 @@ func (g *Gemini) Setup(exch *config.ExchangeConfig) {
 
 // GetSymbols returns all available symbols for trading
 func (g *Gemini) GetSymbols() ([]string, error) {
-	symbols := []string{}
+	var symbols []string
 	path := fmt.Sprintf("%s/v%s/%s", g.APIUrl, geminiAPIVersion, geminiSymbols)
 
 	return symbols, g.SendHTTPRequest(path, &symbols)
@@ -255,7 +255,7 @@ func (g *Gemini) GetOrderbook(currencyPair string, params url.Values) (Orderbook
 // default. Can be '1' or 'true' to activate
 func (g *Gemini) GetTrades(currencyPair string, params url.Values) ([]Trade, error) {
 	path := common.EncodeURLValues(fmt.Sprintf("%s/v%s/%s/%s", g.APIUrl, geminiAPIVersion, geminiTrades, currencyPair), params)
-	trades := []Trade{}
+	var trades []Trade
 
 	return trades, g.SendHTTPRequest(path, &trades)
 }
@@ -281,7 +281,7 @@ func (g *Gemini) GetAuction(currencyPair string) (Auction, error) {
 // indicative prices and quantities.
 func (g *Gemini) GetAuctionHistory(currencyPair string, params url.Values) ([]AuctionHistory, error) {
 	path := common.EncodeURLValues(fmt.Sprintf("%s/v%s/%s/%s/%s", g.APIUrl, geminiAPIVersion, geminiAuction, currencyPair, geminiAuctionHistory), params)
-	auctionHist := []AuctionHistory{}
+	var auctionHist []AuctionHistory
 
 	return auctionHist, g.SendHTTPRequest(path, &auctionHist)
 }
@@ -397,7 +397,7 @@ func (g *Gemini) GetOrders() ([]Order, error) {
 // currencyPair - example "btcusd"
 // timestamp - [optional] Only return trades on or after this timestamp.
 func (g *Gemini) GetTradeHistory(currencyPair string, timestamp int64) ([]TradeHistory, error) {
-	response := []TradeHistory{}
+	var response []TradeHistory
 	req := make(map[string]interface{})
 	req["symbol"] = currencyPair
 
@@ -419,7 +419,7 @@ func (g *Gemini) GetNotionalVolume() (NotionalVolume, error) {
 
 // GetTradeVolume returns a multi-arrayed volume response
 func (g *Gemini) GetTradeVolume() ([][]TradeVolume, error) {
-	response := [][]TradeVolume{}
+	var response [][]TradeVolume
 
 	return response,
 		g.SendAuthenticatedHTTPRequest(http.MethodPost, geminiTradeVolume, nil, &response)
@@ -427,7 +427,7 @@ func (g *Gemini) GetTradeVolume() ([][]TradeVolume, error) {
 
 // GetBalances returns available balances in the supported currencies
 func (g *Gemini) GetBalances() ([]Balance, error) {
-	response := []Balance{}
+	var response []Balance
 
 	return response,
 		g.SendAuthenticatedHTTPRequest(http.MethodPost, geminiBalances, nil, &response)

exchanges/hitbtc/hitbtc.go

@@ -172,7 +172,7 @@ func (h *HitBTC) GetCurrency(currency string) (Currencies, error) {
 // pair indicates how much of the quote currency is needed to purchase one unit
 // of the base currency.
 func (h *HitBTC) GetSymbols(symbol string) ([]string, error) {
-	resp := []Symbol{}
+	var resp []Symbol
 	path := fmt.Sprintf("%s/%s/%s", h.APIUrl, apiV2Symbol, symbol)
 
 	ret := make([]string, 0, len(resp))
@@ -190,7 +190,7 @@ func (h *HitBTC) GetSymbols(symbol string) ([]string, error) {
 // GetSymbolsDetailed is the same as above but returns an array of symbols with
 // all their details.
 func (h *HitBTC) GetSymbolsDetailed() ([]Symbol, error) {
-	resp := []Symbol{}
+	var resp []Symbol
 	path := fmt.Sprintf("%s/%s", h.APIUrl, apiV2Symbol)
 
 	return resp, h.SendHTTPRequest(path, &resp)
@@ -198,7 +198,7 @@ func (h *HitBTC) GetSymbolsDetailed() ([]Symbol, error) {
 
 // GetTicker returns ticker information
 func (h *HitBTC) GetTicker(symbol string) (map[string]Ticker, error) {
-	resp1 := []TickerResponse{}
+	var resp1 []TickerResponse
 	resp2 := TickerResponse{}
 	ret := make(map[string]TickerResponse)
 	result := make(map[string]Ticker)
@@ -292,7 +292,7 @@ func (h *HitBTC) GetTrades(currencyPair, from, till, limit, offset, by, sort str
 		vals.Set("sort", sort)
 	}
 
-	resp := []TradeHistory{}
+	var resp []TradeHistory
 	path := fmt.Sprintf("%s/%s/%s?%s", h.APIUrl, apiV2Trades, currencyPair, vals.Encode())
 
 	return resp, h.SendHTTPRequest(path, &resp)
@@ -337,7 +337,7 @@ func (h *HitBTC) GetCandles(currencyPair, limit, period string) ([]ChartData, er
 		vals.Set("period", period)
 	}
 
-	resp := []ChartData{}
+	var resp []ChartData
 	path := fmt.Sprintf("%s/%s/%s?%s", h.APIUrl, apiV2Candles, currencyPair, vals.Encode())
 
 	return resp, h.SendHTTPRequest(path, &resp)
@@ -348,7 +348,7 @@ func (h *HitBTC) GetCandles(currencyPair, limit, period string) ([]ChartData, er
 
 // GetBalances returns full balance for your account
 func (h *HitBTC) GetBalances() (map[string]Balance, error) {
-	result := []Balance{}
+	var result []Balance
 	err := h.SendAuthenticatedHTTPRequest(http.MethodGet, apiV2Balance, url.Values{}, &result)
 	ret := make(map[string]Balance)
 
@@ -384,7 +384,7 @@ func (h *HitBTC) GenerateNewAddress(currency string) (DepositCryptoAddresses, er
 
 // GetActiveorders returns all your active orders
 func (h *HitBTC) GetActiveorders(currency string) ([]Order, error) {
-	resp := []Order{}
+	var resp []Order
 	err := h.SendAuthenticatedHTTPRequest(http.MethodGet, orders+"?symbol="+currency, url.Values{}, &resp)
 
 	return resp, err

exchanges/itbit/itbit.go

@@ -142,7 +142,7 @@ func (i *ItBit) GetTradeHistory(currencyPair, timestamp string) (Trades, error)
 // 					page - [optional] page to return example 1. default 1
 //					perPage - [optional] items per page example 50, default 50 max 50
 func (i *ItBit) GetWallets(params url.Values) ([]Wallet, error) {
-	resp := []Wallet{}
+	var resp []Wallet
 	params.Set("userId", i.ClientID)
 	path := fmt.Sprintf("/%s?%s", itbitWallets, params.Encode())
 

exchanges/lakebtc/lakebtc.go

@@ -205,7 +205,7 @@ func (l *LakeBTC) GetOrderBook(currency string) (Orderbook, error) {
 // GetTradeHistory returns the trade history for a given currency pair
 func (l *LakeBTC) GetTradeHistory(currency string) ([]TradeHistory, error) {
 	path := fmt.Sprintf("%s/%s?symbol=%s", l.APIUrl, lakeBTCTrades, common.StringToLower(currency))
-	resp := []TradeHistory{}
+	var resp []TradeHistory
 
 	return resp, l.SendHTTPRequest(path, &resp)
 }
@@ -242,7 +242,7 @@ func (l *LakeBTC) Trade(isBuyOrder bool, amount, price float64, currency string)
 
 // GetOpenOrders returns all open orders associated with your account
 func (l *LakeBTC) GetOpenOrders() ([]OpenOrders, error) {
-	orders := []OpenOrders{}
+	var orders []OpenOrders
 
 	return orders, l.SendAuthenticatedHTTPRequest(lakeBTCOpenOrders, "", &orders)
 }
@@ -254,7 +254,7 @@ func (l *LakeBTC) GetOrders(orders []int64) ([]Orders, error) {
 		ordersStr = append(ordersStr, strconv.FormatInt(x, 10))
 	}
 
-	resp := []Orders{}
+	var resp []Orders
 	return resp,
 		l.SendAuthenticatedHTTPRequest(lakeBTCGetOrders, common.JoinStrings(ordersStr, ","), &resp)
 }
@@ -304,13 +304,13 @@ func (l *LakeBTC) GetTrades(timestamp int64) ([]AuthenticatedTradeHistory, error
 		params = strconv.FormatInt(timestamp, 10)
 	}
 
-	trades := []AuthenticatedTradeHistory{}
+	var trades []AuthenticatedTradeHistory
 	return trades, l.SendAuthenticatedHTTPRequest(lakeBTCGetTrades, params, &trades)
 }
 
 // GetExternalAccounts returns your external accounts WARNING: Only for BTC!
 func (l *LakeBTC) GetExternalAccounts() ([]ExternalAccounts, error) {
-	resp := []ExternalAccounts{}
+	var resp []ExternalAccounts
 
 	return resp, l.SendAuthenticatedHTTPRequest(lakeBTCGetExternalAccounts, "", &resp)
 }

exchanges/localbitcoins/localbitcoins.go

@@ -461,7 +461,7 @@ func (l *LocalBitcoins) DeleteInvoice() (Invoice, error) {
 
 // GetNotifications returns recent notifications.
 func (l *LocalBitcoins) GetNotifications() ([]NotificationInfo, error) {
-	resp := []NotificationInfo{}
+	var resp []NotificationInfo
 	return resp, l.SendAuthenticatedHTTPRequest(http.MethodPost, localbitcoinsAPIGetNotification, nil, &resp)
 }
 
@@ -668,7 +668,7 @@ func (l *LocalBitcoins) GetTradableCurrencies() ([]string, error) {
 // updated every 15 minutes.
 func (l *LocalBitcoins) GetTrades(currency string, values url.Values) ([]Trade, error) {
 	path := common.EncodeURLValues(fmt.Sprintf("%s/%s/trades.json", l.APIUrl+localbitcoinsAPIBitcoincharts, currency), values)
-	result := []Trade{}
+	var result []Trade
 
 	return result, l.SendHTTPRequest(path, &result)
 }

exchanges/okgroup/okgroup.go

@@ -275,7 +275,7 @@ func (o *OKGroup) PlaceMultipleSpotOrders(request []PlaceSpotOrderRequest) (map[
 		return resp, []error{err}
 	}
 
-	orderErrors := []error{}
+	var orderErrors []error
 	for currency, orderResponse := range resp {
 		for _, order := range orderResponse {
 			if !order.Result {
@@ -283,9 +283,6 @@ func (o *OKGroup) PlaceMultipleSpotOrders(request []PlaceSpotOrderRequest) (map[
 			}
 		}
 	}
-	if len(orderErrors) == 0 {
-		orderErrors = nil
-	}
 
 	return resp, orderErrors
 }
@@ -475,7 +472,7 @@ func (o *OKGroup) PlaceMultipleMarginOrders(request []PlaceSpotOrderRequest) (ma
 		return resp, []error{err}
 	}
 
-	orderErrors := []error{}
+	var orderErrors []error
 	for currency, orderResponse := range resp {
 		for _, order := range orderResponse {
 			if !order.Result {
@@ -483,9 +480,6 @@ func (o *OKGroup) PlaceMultipleMarginOrders(request []PlaceSpotOrderRequest) (ma
 			}
 		}
 	}
-	if len(orderErrors) == 0 {
-		orderErrors = nil
-	}
 
 	return resp, orderErrors
 }
@@ -508,7 +502,7 @@ func (o *OKGroup) CancelMultipleMarginOrders(request CancelMultipleSpotOrdersReq
 		return resp, []error{err}
 	}
 
-	orderErrors := []error{}
+	var orderErrors []error
 	for currency, orderResponse := range resp {
 		for _, order := range orderResponse {
 			if !order.Result {
@@ -516,9 +510,6 @@ func (o *OKGroup) CancelMultipleMarginOrders(request CancelMultipleSpotOrdersReq
 			}
 		}
 	}
-	if len(orderErrors) == 0 {
-		orderErrors = nil
-	}
 
 	return resp, orderErrors
 }

exchanges/orders/orders.go

@@ -46,7 +46,7 @@ func DeleteOrder(orderID int) bool {
 
 // GetOrdersByExchange returns order pointer grouped by exchange
 func GetOrdersByExchange(exchange string) []*Order {
-	orders := []*Order{}
+	var orders []*Order
 	for i := range Orders {
 		if Orders[i].Exchange == exchange {
 			orders = append(orders, Orders[i])

exchanges/poloniex/poloniex.go

@@ -248,7 +248,7 @@ func (p *Poloniex) GetTradeHistory(currencyPair, start, end string) ([]TradeHist
 		vals.Set("end", end)
 	}
 
-	resp := []TradeHistory{}
+	var resp []TradeHistory
 	path := fmt.Sprintf("%s/public?command=returnTradeHistory&%s", p.APIUrl, vals.Encode())
 
 	return resp, p.SendHTTPRequest(path, &resp)
@@ -271,7 +271,7 @@ func (p *Poloniex) GetChartData(currencyPair, start, end, period string) ([]Char
 		vals.Set("period", period)
 	}
 
-	resp := []ChartData{}
+	var resp []ChartData
 	path := fmt.Sprintf("%s/public?command=returnChartData&%s", p.APIUrl, vals.Encode())
 
 	err := p.SendHTTPRequest(path, &resp)
@@ -822,7 +822,7 @@ func (p *Poloniex) GetLendingHistory(start, end string) ([]LendingHistory, error
 		vals.Set("end", end)
 	}
 
-	resp := []LendingHistory{}
+	var resp []LendingHistory
 	err := p.SendAuthenticatedHTTPRequest(http.MethodPost,
 		poloniexLendingHistory,
 		vals,

exchanges/zb/zb.go

@@ -321,7 +321,7 @@ func (z *ZB) GetSpotKline(arg KlinesRequestParams) (KLineResponse, error) {
 	res.MoneyType = rawKlines["moneyType"].(string)
 
 	rawKlineDatasString, _ := json.Marshal(rawKlines["data"].([]interface{}))
-	rawKlineDatas := [][]interface{}{}
+	var rawKlineDatas [][]interface{}
 	if err := json.Unmarshal(rawKlineDatasString, &rawKlineDatas); err != nil {
 		return res, errors.New("zb rawKlines unmarshal failed")
 	}

helpers_test.go

@@ -264,7 +264,7 @@ func TestGetSpecificOrderbook(t *testing.T) {
 
 	LoadExchange("Bitstamp", false, nil)
 
-	bids := []orderbook.Item{}
+	var bids []orderbook.Item
 	bids = append(bids, orderbook.Item{Price: 1000, Amount: 1})
 
 	base := orderbook.Base{
@@ -329,7 +329,7 @@ func TestGetSpecificTicker(t *testing.T) {
 func TestGetCollatedExchangeAccountInfoByCoin(t *testing.T) {
 	SetupTestHelpers(t)
 
-	exchangeInfo := []exchange.AccountInfo{}
+	var exchangeInfo []exchange.AccountInfo
 	var info exchange.AccountInfo
 
 	info.Exchange = "Bitfinex"
@@ -383,7 +383,7 @@ func TestGetCollatedExchangeAccountInfoByCoin(t *testing.T) {
 func TestGetAccountCurrencyInfoByExchangeName(t *testing.T) {
 	SetupTestHelpers(t)
 
-	exchangeInfo := []exchange.AccountInfo{}
+	var exchangeInfo []exchange.AccountInfo
 	var info exchange.AccountInfo
 	info.Exchange = "Bitfinex"
 	info.Accounts = append(info.Accounts,