cmd: add exchangetest cmd and document NewWithEnvVarPrefix

pkg/cmd/exchangetest.go

@@ -0,0 +1,107 @@
+package cmd
+
+import (
+	"context"
+	"fmt"
+	"syscall"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+	"github.com/spf13/cobra"
+
+	"github.com/c9s/bbgo/pkg/bbgo"
+	"github.com/c9s/bbgo/pkg/cmd/cmdutil"
+	"github.com/c9s/bbgo/pkg/types"
+)
+
+// go run ./cmd/bbgo kline --exchange=binance --symbol=BTCUSDT
+var exchangeTestCmd = &cobra.Command{
+	Use:   "exchange-test",
+	Short: "test the exchange",
+	PreRunE: cobraInitRequired([]string{
+		"session",
+		"symbol",
+		"interval",
+	}),
+	RunE: func(cmd *cobra.Command, args []string) error {
+		ctx := context.Background()
+
+		environ := bbgo.NewEnvironment()
+		if err := environ.ConfigureExchangeSessions(userConfig); err != nil {
+			return err
+		}
+
+		sessionName, err := cmd.Flags().GetString("session")
+		if err != nil {
+			return err
+		}
+
+		session, ok := environ.Session(sessionName)
+		if !ok {
+			return fmt.Errorf("session %s not found", sessionName)
+		}
+
+		symbol, err := cmd.Flags().GetString("symbol")
+		if err != nil {
+			return fmt.Errorf("can not get the symbol from flags: %w", err)
+		}
+
+		if symbol == "" {
+			return fmt.Errorf("--symbol option is required")
+		}
+
+		interval, err := cmd.Flags().GetString("interval")
+		if err != nil {
+			return err
+		}
+
+		now := time.Now()
+		kLines, err := session.Exchange.QueryKLines(ctx, symbol, types.Interval(interval), types.KLineQueryOptions{
+			Limit:   50,
+			EndTime: &now,
+		})
+		if err != nil {
+			return err
+		}
+		log.Infof("kLines from RESTful API")
+		for _, k := range kLines {
+			log.Info(k.String())
+		}
+
+		s := session.Exchange.NewStream()
+		s.SetPublicOnly()
+		s.Subscribe(types.KLineChannel, symbol, types.SubscribeOptions{Interval: types.Interval(interval)})
+
+		s.OnKLineClosed(func(kline types.KLine) {
+			log.Infof("kline closed: %s", kline.String())
+		})
+
+		s.OnKLine(func(kline types.KLine) {
+			log.Infof("kline: %s", kline.String())
+		})
+
+		log.Infof("connecting...")
+		if err := s.Connect(ctx); err != nil {
+			return err
+		}
+
+		log.Infof("connected")
+		defer func() {
+			log.Infof("closing connection...")
+			if err := s.Close(); err != nil {
+				log.WithError(err).Errorf("connection close error")
+			}
+		}()
+
+		cmdutil.WaitForSignal(ctx, syscall.SIGINT, syscall.SIGTERM)
+		return nil
+	},
+}
+
+func init() {
+	// since the public data does not require trading authentication, we use --exchange option here.
+	exchangeTestCmd.Flags().String("session", "", "session name")
+	exchangeTestCmd.Flags().String("symbol", "", "the trading pair. e.g, BTCUSDT, LTCUSDT...")
+	exchangeTestCmd.Flags().String("interval", "1m", "interval of the kline (candle), .e.g, 1m, 3m, 15m")
+	RootCmd.AddCommand(exchangeTestCmd)
+}

pkg/exchange/factory.go

@@ -37,6 +37,8 @@ func NewStandard(n types.ExchangeName, key, secret, passphrase, subAccount strin
 	}
 }
 
+// NewWithEnvVarPrefix allocate and initialize the exchange instance with the given environment variable prefix
+// When the varPrefix is a empty string, the default exchange name will be used as the prefix
 func NewWithEnvVarPrefix(n types.ExchangeName, varPrefix string) (types.Exchange, error) {
 	if len(varPrefix) == 0 {
 		varPrefix = n.String()