Merge Golang Models

merge-go-models.go

// MergeRecord
// if currentRecord.Field exists -> uses currentRecord.Field
// if currentRecord.Field exists  AND newRecord.Field exists -> uses currentRecord.Field
// if currentRecord.Field does not exist AND newRecord.Field exists -> uses newRecord.Field
func MergeRecord[M any](currentRecord M, newRecord M) M {
	currentValue := reflect.ValueOf(&currentRecord).Elem()
	newValue := reflect.ValueOf(&newRecord).Elem()

	for i := 0; i < currentValue.NumField(); i++ {
		currentField := currentValue.Field(i)
		newField := newValue.Field(i)

		if currentField.IsZero() || (currentField.Kind() == reflect.Ptr && currentField.IsNil()) {
			if !newField.IsZero() || (newField.Kind() == reflect.Ptr && !newField.IsNil()) {
				if currentField.CanSet() {
					currentField.Set(newField)
				}
			}
		}
	}

	return currentRecord
}