improve config loader

pkg/config/loader.go

@@ -0,0 +1,105 @@
+package config
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"reflect"
+
+	"github.com/pkg/errors"
+	"gopkg.in/yaml.v3"
+
+	"github.com/c9s/bbgo/pkg/bbgo"
+)
+
+type Config struct {
+	ExchangeStrategies      []bbgo.SingleExchangeStrategy
+	CrossExchangeStrategies []bbgo.CrossExchangeStrategy
+}
+
+type Stash map[string]interface{}
+
+func loadStash(configFile string) (Stash, error) {
+	config, err := ioutil.ReadFile(configFile)
+	if err != nil {
+		return nil, err
+	}
+
+	stash := make(Stash)
+	if err := yaml.Unmarshal(config, stash); err != nil {
+		return nil, err
+	}
+
+	return stash, err
+}
+
+func Load(configFile string) (*Config, error) {
+	var config Config
+
+	stash, err := loadStash(configFile)
+	if err != nil {
+		return nil, err
+	}
+
+	strategies, err := loadExchangeStrategies(stash)
+	if err != nil {
+		return nil, err
+	}
+
+	config.ExchangeStrategies = strategies
+	return &config, nil
+}
+
+func loadExchangeStrategies(stash Stash) (strategies []bbgo.SingleExchangeStrategy, err error) {
+	exchangeStrategiesConf, ok := stash["exchangeStrategies"]
+	if !ok {
+		return nil, errors.New("exchangeStrategies is not defined")
+	}
+
+	list, ok := exchangeStrategiesConf.([]interface{})
+	if !ok {
+		return nil, errors.New("exchangeStrategies should be a list")
+	}
+
+	for _, entry := range list {
+		configStash, ok := entry.(Stash)
+		if !ok {
+			return nil, errors.Errorf("strategy config should be a map, given: %T %+v", entry, entry)
+		}
+
+		for id, conf := range configStash {
+			// look up the real struct type
+			if st, ok := bbgo.LoadedExchangeStrategies[id]; ok {
+				val, err := reUnmarshal(conf, st)
+				if err != nil {
+					return nil, err
+				}
+
+				strategies = append(strategies, val.(bbgo.SingleExchangeStrategy))
+			}
+		}
+	}
+
+	return strategies, nil
+}
+
+func reUnmarshal(conf interface{}, tpe interface{}) (interface{}, error) {
+	// get the type "*Strategy"
+	rt := reflect.TypeOf(tpe)
+
+	// allocate new object from the given type
+	val := reflect.New(rt)
+
+	// now we have &(*Strategy) -> **Strategy
+	valRef := val.Interface()
+
+	plain, err := json.Marshal(conf)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := json.Unmarshal(plain, valRef); err != nil {
+		return nil, errors.Wrapf(err, "json parsing error, given payload: %s", plain)
+	}
+
+	return val.Elem().Interface(), nil
+}

pkg/config/loader_test.go

@@ -1,4 +1,4 @@
-package loader
+package config
 
 import (
 	"testing"
@@ -32,18 +32,21 @@ func TestLoadStrategies(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			strategies, err := LoadExchangeStrategies(tt.args.configFile)
+			config, err := Load(tt.args.configFile)
 			if err != nil {
-				t.Errorf("LoadExchangeStrategies() error = %v", err)
+				t.Errorf("Load() error = %v", err)
+				return
 			} else {
 				if tt.wantErr {
-					t.Errorf("LoadExchangeStrategies() error = %v, wantErr %v", err, tt.wantErr)
+					t.Errorf("Load() error = %v, wantErr %v", err, tt.wantErr)
+					return
 				}
 			}
 
-			t.Logf("%+v", strategies[0])
+			assert.NotNil(t, config)
+			assert.Len(t, config.ExchangeStrategies, tt.length)
 
-			assert.Len(t, strategies, tt.length)
+			t.Logf("%+v", config.ExchangeStrategies[0])
 		})
 	}
 }

pkg/config/testdata/strategy.yaml

@@ -0,0 +1,16 @@
+---
+sessions:
+  max:
+    exchange: max
+    keyVar: MAX_API_KEY
+    secretVar: MAX_API_SECRET
+  binance:
+    exchange: binance
+    keyVar: BINANCE_API_KEY
+    secretVar: BINANCE_API_SECRET
+exchangeStrategies:
+- buyandhold:
+    symbol: "BTCUSDT"
+    interval: "1m"
+    baseQuantity: 0.1
+    minDropPercentage: -0.05

pkg/loader/loader.go

@@ -1,76 +0,0 @@
-package loader
-
-import (
-	"encoding/json"
-	"io/ioutil"
-	"reflect"
-
-	"github.com/pkg/errors"
-	"gopkg.in/yaml.v3"
-
-	"github.com/c9s/bbgo/pkg/bbgo"
-)
-
-type Stash map[string]interface{}
-
-func Load(configFile string) (Stash, error) {
-	config, err := ioutil.ReadFile(configFile)
-	if err != nil {
-		return nil, err
-	}
-
-	stash := make(Stash)
-	if err := yaml.Unmarshal(config, stash); err != nil {
-		return nil, err
-	}
-
-	return stash, err
-}
-
-func LoadExchangeStrategies(configFile string) (strategies []bbgo.SingleExchangeStrategy, err error) {
-	stash, err := Load(configFile)
-	if err != nil {
-		return nil, err
-	}
-
-	exchangeStrategiesConf, ok := stash["exchangeStrategies"]
-	if !ok {
-		return nil, errors.New("exchangeStrategies is not defined")
-	}
-
-	strategiesConfList, ok := exchangeStrategiesConf.([]interface{})
-	if !ok {
-		return nil, errors.New("exchangeStrategies should be a list")
-	}
-
-	for _, strategiesConf := range strategiesConfList {
-		sConf, ok := strategiesConf.(map[string]interface{})
-		if !ok {
-			return nil, errors.New("strategy config should be a map")
-		}
-
-		for id, conf := range sConf {
-			if st, ok := bbgo.LoadedExchangeStrategies[id]; ok {
-				// get the type "*Strategy"
-				rt := reflect.TypeOf(st)
-				val := reflect.New(rt)
-
-				// now we have &(*Strategy) -> **Strategy
-				valRef := val.Interface()
-
-				plain, err := json.Marshal(conf)
-				if err != nil {
-					return nil, err
-				}
-
-				if err := json.Unmarshal(plain, valRef); err != nil {
-					return nil, errors.Wrapf(err, "json parsing error, given payload: %s", plain)
-				}
-
-				strategies = append(strategies, val.Elem().Interface().(bbgo.SingleExchangeStrategy))
-			}
-		}
-	}
-
-	return strategies, nil
-}

pkg/loader/testdata/strategy.yaml

@@ -1,7 +0,0 @@
----
-exchangeStrategies:
-- buyandhold:
-    symbol: "BTCUSDT"
-    interval: "1m"
-    baseQuantity: 0.1
-    minDropPercentage: -0.05