Extract NewType function to be reused

metric/types.go

@@ -56,20 +56,31 @@ func (t Type) String() string {
 	}
 }
 
+// NewType creates a metric type from a type string.
+func NewType(typeStr string) (Type, error) {
+	validTypeStrs := make([]string, 0, len(validTypes))
+	for _, valid := range validTypes {
+		if typeStr == valid.String() {
+			return valid, nil
+		}
+		validTypeStrs = append(validTypeStrs, valid.String())
+	}
+	return UnknownType, fmt.Errorf("invalid metric type '%s', valid types are: %s",
+		typeStr, strings.Join(validTypeStrs, ", "))
+}
+
 // UnmarshalYAML unmarshals YAML object into a metric type.
 func (t *Type) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	var str string
 	if err := unmarshal(&str); err != nil {
 		return err
 	}
-	validTypeStrs := make([]string, 0, len(validTypes))
-	for _, valid := range validTypes {
-		if str == valid.String() {
-			*t = valid
-			return nil
-		}
-		validTypeStrs = append(validTypeStrs, valid.String())
+
+	mt, err := NewType(str)
+	if err != nil {
+		return err
 	}
-	return fmt.Errorf("invalid metric type '%s' valid types are: %s",
-		str, strings.Join(validTypeStrs, ", "))
+
+	*t = mt
+	return nil
 }

metric/types_test.go

@@ -52,6 +52,6 @@ func TestTypeUnmarshalYAMLErrors(t *testing.T) {
 		var typ Type
 		err := yaml.Unmarshal([]byte(input), &typ)
 		require.Error(t, err)
-		require.Equal(t, "invalid metric type '"+input+"' valid types are: counter, timer, gauge", err.Error())
+		require.Equal(t, "invalid metric type '"+input+"', valid types are: counter, timer, gauge", err.Error())
 	}
 }