Merge pull request #8 from ataklychev/master

normalize empty error from gorm to nil

crud_repository.go

@@ -147,7 +147,7 @@ func (c CrudRepository) GetModel() InterfaceEntity {
 func (c CrudRepository) Find(id uint) (InterfaceEntity, error) {
 	item := reflect.New(reflect.TypeOf(c.GetModel()).Elem()).Interface()
 	err := c.Db.First(item, id).Error
-	return item, err
+	return item, NormalizeErr(err)
 }
 
 func (c CrudRepository) PluckBy(fieldNames []string) (map[string]int64, error) {
@@ -232,7 +232,7 @@ func (c CrudRepository) List(parameters ListParametersInterface) ([]InterfaceEnt
 		data = append(data, sliceValue.Index(i).Interface())
 	}
 
-	return data, err
+	return data, NormalizeErr(err)
 }
 
 func (c CrudRepository) Create(item InterfaceEntity) InterfaceEntity {
@@ -361,6 +361,7 @@ func (c CrudRepository) CreateOrUpdateMany(
 		onConflict)
 
 	err := c.Db.Exec(query).Error
+	err = NormalizeErr(err)
 	if nil != err {
 		c.Logger.Errorf("gorm-crud: Error in the CreateOrUpdateMany(): %v", err)
 	}
@@ -375,6 +376,7 @@ func (c CrudRepository) Update(item InterfaceEntity) InterfaceEntity {
 
 func (c CrudRepository) Delete(id uint) error {
 	item, err := c.Find(id)
+	err = NormalizeErr(err)
 	if err != nil {
 		return err
 	}

helper.go

@@ -2,6 +2,7 @@ package gorm_crud
 
 import (
 	"fmt"
+	"reflect"
 	"strconv"
 )
 
@@ -14,3 +15,21 @@ func Num64(n interface{}) int64 {
 		return i
 	}
 }
+
+func IsNil(i interface{}) bool {
+	if i == nil {
+		return true
+	}
+	switch reflect.TypeOf(i).Kind() {
+	case reflect.Ptr, reflect.Map, reflect.Array, reflect.Chan, reflect.Slice:
+		return reflect.ValueOf(i).IsNil()
+	}
+	return false
+}
+
+func NormalizeErr(err error) error {
+	if IsNil(err) {
+		return nil
+	}
+	return err
+}