cli_tools/common/assert/assert.go

//  Copyright 2020 Google Inc. All Rights Reserved.
//
//  Licensed under the Apache License, Version 2.0 (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS,
//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//  See the License for the specific language governing permissions and
//  limitations under the License.

package assert

import (
	"fmt"
	"reflect"

	"github.com/GoogleCloudPlatform/compute-image-tools/cli_tools/common/utils/files"
)

// NotEmpty asserts that obj is non-null and does not have a zero value.
func NotEmpty(obj interface{}) {
	if isEmpty(obj) {
		panic("Expected non-empty value")
	}
}

func isEmpty(obj interface{}) bool {
	if obj == nil {
		return true
	}

	v := reflect.ValueOf(obj)
	switch v.Kind() {
	case reflect.Array, reflect.Map, reflect.Slice, reflect.String:
		return v.Len() == 0
	}
	return v.IsZero()
}

// GreaterThanOrEqualTo asserts that value is greater than or equal to limit.
func GreaterThanOrEqualTo(value int, limit int) {
	if value < limit {
		panic(fmt.Sprintf("Expected %d >= %d", value, limit))
	}
}

// Contains asserts that element is a member of arr.
func Contains(element string, arr []string) {
	for _, e := range arr {
		if e == element {
			return
		}
	}
	panic(fmt.Sprintf("%s is not a member of %v", element, arr))
}

// DirectoryExists asserts that a directory is on the current filesystem.
func DirectoryExists(dir string) {
	if !files.DirectoryExists(dir) {
		panic(fmt.Sprintf("%s: Directory not found", dir))
	}
}