codebase: Cleanup various things (#1935)

* codebase: Rid base64/hex to string common funcs

* codebase: Rid local scope variable usage and other improvements

* codebase: Refactor currency pair usage across multiple exchanges

- Updated HitBTC tests to use the new currency pair format.
- Modified Kraken futures types to use currency.Pair instead of string for Symbol.
- Adjusted Kraken wrapper methods to handle currency pairs correctly.
- Refined OKX tests and types to utilize currency.Pair for instrument IDs.
- Enhanced Poloniex tests to consistently use predefined currency pairs.
- Streamlined order and orderbook tests to replace string pairs with currency.NewBTCUSD().
- Improved Yobit tests to utilize a standardized currency pair format.
- Updated validator wrapper to use currency pairs directly instead of string conversions.

* codebase: Use types.Number where possible

* refactor: update PayoutFee type to types.Number for consistency

* Refactor: Remove crypto functions to use standard library and other minor changes

- Removed custom crypto functions for SHA256, SHA512, and MD5 from the common/crypto package.
- Replaced usages of removed functions with standard library implementations in various files including:
  - cmd/websocket_client/main.go
  - engine/apiserver.go
  - exchanges/kraken/kraken.go
  - exchanges/lbank/lbank.go
  - exchanges/okx/okx_business_websocket.go
  - exchanges/kucoin/kucoin_websocket.go
  - gctscript/vm/vm.go
- Updated tests to reflect changes in the crypto functions.
- Renamed several functions for clarity, particularly in the context of order book updates across multiple exchanges.

* refactor: replace assert with require for consistency in test assertions

* refactor: Improve Binance futures candlestick test, standardise orderbook update function names and improve test parallelism

* refactor: Replace require.Len with require.Equal for better output in TestGetFuturesKlineData

exchanges/huobi/huobi.go

@@ -3,6 +3,7 @@ package huobi
 import (
 	"bytes"
 	"context"
+	"encoding/base64"
 	"errors"
 	"fmt"
 	"net/http"
@@ -949,16 +950,12 @@ func (h *HUOBI) SendAuthenticatedHTTPRequest(ctx context.Context, ep exchange.UR
 			headers["Content-Type"] = "application/json"
 		}
 
-		var hmac []byte
-		hmac, err = crypto.GetHMAC(crypto.HashSHA256,
-			[]byte(payload),
-			[]byte(creds.Secret))
+		hmac, err := crypto.GetHMAC(crypto.HashSHA256, []byte(payload), []byte(creds.Secret))
 		if err != nil {
 			return nil, err
 		}
 
-		values.Set("Signature", crypto.Base64Encode(hmac))
-		urlPath := ePoint + common.EncodeURLValues(endpoint, values)
+		values.Set("Signature", base64.StdEncoding.EncodeToString(hmac))
 
 		var body []byte
 		if data != nil {
@@ -970,7 +967,7 @@ func (h *HUOBI) SendAuthenticatedHTTPRequest(ctx context.Context, ep exchange.UR
 
 		return &request.Item{
 			Method:        method,
-			Path:          urlPath,
+			Path:          ePoint + common.EncodeURLValues(endpoint, values),
 			Headers:       headers,
 			Body:          bytes.NewReader(body),
 			Result:        &interim,

exchanges/huobi/huobi_futures.go

@@ -3,6 +3,7 @@ package huobi
 import (
 	"bytes"
 	"context"
+	"encoding/base64"
 	"errors"
 	"fmt"
 	"io"
@@ -1167,15 +1168,12 @@ func (h *HUOBI) FuturesAuthenticatedHTTPRequest(ctx context.Context, ep exchange
 			headers["Content-Type"] = "application/json"
 		}
 
-		var hmac []byte
-		hmac, err = crypto.GetHMAC(crypto.HashSHA256,
-			[]byte(sigPath),
-			[]byte(creds.Secret))
+		hmac, err := crypto.GetHMAC(crypto.HashSHA256, []byte(sigPath), []byte(creds.Secret))
 		if err != nil {
 			return nil, err
 		}
-		values.Add("Signature", crypto.Base64Encode(hmac))
-		urlPath := common.EncodeURLValues(ePoint+endpoint, values)
+
+		values.Add("Signature", base64.StdEncoding.EncodeToString(hmac))
 		var body io.Reader
 		var payload []byte
 		if data != nil {
@@ -1188,7 +1186,7 @@ func (h *HUOBI) FuturesAuthenticatedHTTPRequest(ctx context.Context, ep exchange
 
 		return &request.Item{
 			Method:        method,
-			Path:          urlPath,
+			Path:          common.EncodeURLValues(ePoint+endpoint, values),
 			Headers:       headers,
 			Body:          body,
 			Result:        &tempResp,

exchanges/huobi/huobi_test.go

@@ -493,9 +493,7 @@ func TestGetOrderHistory(t *testing.T) {
 	_, err := h.GetOrderHistory(t.Context(), &getOrdersRequest)
 	require.NoError(t, err)
 
-	cp1, err := currency.NewPairFromString("ADA-USD")
-	require.NoError(t, err)
-	getOrdersRequest.Pairs = []currency.Pair{cp1}
+	getOrdersRequest.Pairs = []currency.Pair{btcusdPair}
 	getOrdersRequest.AssetType = asset.CoinMarginedFutures
 	_, err = h.GetOrderHistory(t.Context(), &getOrdersRequest)
 	require.NoError(t, err)
@@ -959,9 +957,7 @@ func TestGetCurrencies(t *testing.T) {
 
 func TestGet24HrMarketSummary(t *testing.T) {
 	t.Parallel()
-	cp, err := currency.NewPairFromString("ethusdt")
-	require.NoError(t, err)
-	_, err = h.Get24HrMarketSummary(t.Context(), cp)
+	_, err := h.Get24HrMarketSummary(t.Context(), btcusdtPair)
 	require.NoError(t, err)
 }
 
@@ -1620,7 +1616,7 @@ func TestStringToOrderType(t *testing.T) {
 	}
 }
 
-func Test_FormatExchangeKlineInterval(t *testing.T) {
+func TestFormatExchangeKlineInterval(t *testing.T) {
 	t.Parallel()
 	for _, tt := range []struct {
 		interval kline.Interval

exchanges/huobi/huobi_websocket.go

@@ -2,6 +2,7 @@ package huobi
 
 import (
 	"context"
+	"encoding/base64"
 	"errors"
 	"fmt"
 	"net/http"
@@ -579,7 +580,6 @@ func (h *HUOBI) wsLogin(ctx context.Context) error {
 		return err
 	}
 
-	c := h.Websocket.AuthConn
 	ts := time.Now().UTC().Format(wsDateTimeFormatting)
 	hmac, err := h.wsGenerateSignature(creds, ts)
 	if err != nil {
@@ -593,12 +593,12 @@ func (h *HUOBI) wsLogin(ctx context.Context) error {
 			AccessKey:        creds.Key,
 			SignatureMethod:  signatureMethod,
 			SignatureVersion: signatureVersion,
-			Signature:        crypto.Base64Encode(hmac),
+			Signature:        base64.StdEncoding.EncodeToString(hmac),
 			Timestamp:        ts,
 		},
 	}
-	err = c.SendJSONMessage(context.Background(), request.Unset, req)
-	if err != nil {
+	c := h.Websocket.AuthConn
+	if err := c.SendJSONMessage(context.Background(), request.Unset, req); err != nil {
 		return err
 	}
 	resp := c.ReadMessage()