Changes in errors

errors/env.go

@@ -1,7 +1,34 @@
 package errors
 
-import "errors"
+import (
+	"errors"
+	"fmt"
+	"reflect"
+)
 
 var (
-	ENV_EMPTY = errors.New("Environment variable was empty")
+	ENV_EMPTY    = errors.New("Environment variable was empty")
+	NOT_INIT     = errors.New("Is not initialised")
+	NOT_HANDLED  = errors.New("Is not handled")
+	OUT_OF_BOUND = errors.New("Out of bound")
+	NOT_SET      = errors.New("Is not set")
 )
+
+func WrapErr(context string, err error) error {
+	return fmt.Errorf("%s: %w", context, err)
+}
+
+func CheckFieldInitialized(t interface{}, fieldName string) error {
+	v := reflect.ValueOf(t)
+	fieldValue := v.Elem().FieldByName(fieldName)
+
+	if !fieldValue.IsValid() {
+		return fmt.Errorf("field %s does not exist", fieldName)
+	}
+
+	if fieldValue.IsNil() {
+		return WrapErr(fieldName, NOT_INIT)
+	}
+
+	return nil
+}