empty.go raw

   1  // Copyright 2022-2025 The sacloud/packages-go Authors
   2  //
   3  // Licensed under the Apache License, Version 2.0 (the "License");
   4  // you may not use this file except in compliance with the License.
   5  // You may obtain a copy of the License at
   6  //
   7  //      http://www.apache.org/licenses/LICENSE-2.0
   8  //
   9  // Unless required by applicable law or agreed to in writing, software
  10  // distributed under the License is distributed on an "AS IS" BASIS,
  11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  // See the License for the specific language governing permissions and
  13  // limitations under the License.
  14  
  15  package objutil
  16  
  17  import (
  18  	"reflect"
  19  )
  20  
  21  // IsEmpty is copied from github.com/stretchr/testify/assert/assertions.go
  22  func IsEmpty(object interface{}) bool {
  23  	// get nil case out of the way
  24  	if object == nil {
  25  		return true
  26  	}
  27  
  28  	objValue := reflect.ValueOf(object)
  29  
  30  	switch objValue.Kind() {
  31  	// collection types are empty when they have no element
  32  	case reflect.Array, reflect.Chan, reflect.Map, reflect.Slice:
  33  		return objValue.Len() == 0
  34  	// pointers are empty if nil or if the value they point to is empty
  35  	case reflect.Ptr:
  36  		if objValue.IsNil() {
  37  			return true
  38  		}
  39  		deref := objValue.Elem().Interface()
  40  		return IsEmpty(deref)
  41  	// for all other types, compare against the zero value
  42  	default:
  43  		zero := reflect.Zero(objValue.Type())
  44  		return reflect.DeepEqual(object, zero.Interface())
  45  	}
  46  }
  47