Misc small improvements.

config/config.go

@@ -46,26 +46,25 @@ type Asset struct {
 	RelativeBases []moon.RelativeBase `koanf:"relativeBases"`
 }
 
-func (r Root) ForAsset(asset coindesk.Asset) (data Asset) {
-	data, ok := r.Assets[asset]
-	if !ok {
-		data = r.Defaults
-	}
-	if data.Asset == "" {
-		data.Asset = asset
-	}
-	if data.Goals == nil || len(data.Goals) == 0 {
-		data.Goals = r.Defaults.Goals
-	}
-	if data.ConstantBases == nil || len(data.ConstantBases) == 0 {
-		data.ConstantBases = r.Defaults.ConstantBases
-	}
-	if data.RelativeBases == nil || len(data.RelativeBases) == 0 {
-		data.RelativeBases = r.Defaults.RelativeBases
-	}
+func (r Root) ForAsset(a coindesk.Asset) (cfg Asset) {
+	cfg = merge(r.Assets[a], r.Defaults)
+	cfg.Asset = a
 	return
 }
 
+func merge(dst, src Asset) Asset {
+	if len(dst.Goals) == 0 {
+		dst.Goals = src.Goals
+	}
+	if len(dst.ConstantBases) == 0 {
+		dst.ConstantBases = src.ConstantBases
+	}
+	if len(dst.RelativeBases) == 0 {
+		dst.RelativeBases = src.RelativeBases
+	}
+	return dst
+}
+
 // GetBases returns the concatenation of the constant and relative bases, sorted
 // from most recent to least recent in time.
 func GetBases(d *Asset) (bases []moon.Base) {