/*
Package validation provides methods for validating parameter value using reflection.
*/
package validation
// Copyright 2017 Microsoft Corporation
//
// 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.
import (
"fmt"
"reflect"
"regexp"
"strings"
)
// Constraint stores constraint name, target field name
// Rule and chain validations.
type Constraint struct {
// Target field name for validation.
Target string
// Constraint name e.g. minLength, MaxLength, Pattern, etc.
Name string
// Rule for constraint e.g. greater than 10, less than 5 etc.
Rule interface{}
// Chain Validations for struct type
Chain []Constraint
}
// Validation stores parameter-wise validation.
type Validation struct {
TargetValue interface{}
Constraints []Constraint
}
// Constraint list
const (
Empty = "Empty"
Null = "Null"
ReadOnly = "ReadOnly"
Pattern = "Pattern"
MaxLength = "MaxLength"
MinLength = "MinLength"
MaxItems = "MaxItems"
MinItems = "MinItems"
MultipleOf = "MultipleOf"
UniqueItems = "UniqueItems"
InclusiveMaximum = "InclusiveMaximum"
ExclusiveMaximum = "ExclusiveMaximum"
ExclusiveMinimum = "ExclusiveMinimum"
InclusiveMinimum = "InclusiveMinimum"
)
// Validate method validates constraints on parameter
// passed in validation array.
func Validate(m []Validation) error {
for _, item := range m {
v := reflect.ValueOf(item.TargetValue)
for _, constraint := range item.Constraints {
var err error
switch v.Kind() {
case reflect.Ptr:
err = validatePtr(v, constraint)
case reflect.String:
err = validateString(v, constraint)
case reflect.Struct:
err = validateStruct(v, constraint)
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
err = validateInt(v, constraint)
case reflect.Float32, reflect.Float64:
err = validateFloat(v, constraint)
case reflect.Array, reflect.Slice, reflect.Map:
err = validateArrayMap(v, constraint)
default:
err = createError(v, constraint, fmt.Sprintf("unknown type %v", v.Kind()))
}
if err != nil {
return err
}
}
}
return nil
}
func validateStruct(x reflect.Value, v Constraint, name ...string) error {
//Get field name from target name which is in format a.b.c
s := strings.Split(v.Target, ".")
f := x.FieldByName(s[len(s)-1])
if isZero(f) {
return createError(x, v, fmt.Sprintf("field %q doesn't exist", v.Target))
}
return Validate([]Validation{
{
TargetValue: getInterfaceValue(f),
Constraints: []Constraint{v},
},
})
}
func validatePtr(x reflect.Value, v Constraint) error {
if v.Name == ReadOnly {
if !x.IsNil() {
return createError(x.Elem(), v, "readonly parameter; must send as nil or empty in request")
}
return nil
}
if x.IsNil() {
return checkNil(x, v)
}
if v.Chain != nil {
return Validate([]Validation{
{
TargetValue: getInterfaceValue(x.Elem()),
Constraints: v.Chain,
},
})
}
return nil
}
func validateInt(x reflect.Value, v Constraint) error {
i := x.Int()
r, ok := toInt64(v.Rule)
if !ok {
return createError(x, v, fmt.Sprintf("rule must be integer value for %v constraint; got: %v", v.Name, v.Rule))
}
switch v.Name {
case MultipleOf:
if i%r != 0 {
return createError(x, v, fmt.Sprintf("value must be a multiple of %v", r))
}
case ExclusiveMinimum:
if i <= r {
return createError(x, v, fmt.Sprintf("value must be greater than %v", r))
}
case ExclusiveMaximum:
if i >= r {
return createError(x, v, fmt.Sprintf("value must be less than %v", r))
}
case InclusiveMinimum:
if i < r {
return createError(x, v, fmt.Sprintf("value must be greater than or equal to %v", r))
}
case InclusiveMaximum:
if i > r {
return createError(x, v, fmt.Sprintf("value must be less than or equal to %v", r))
}
default:
return createError(x, v, fmt.Sprintf("constraint %v is not applicable for type integer", v.Name))
}
return nil
}
func validateFloat(x reflect.Value, v Constraint) error {
f := x.Float()
r, ok := v.Rule.(float64)
if !ok {
return createError(x, v, fmt.Sprintf("rule must be float value for %v constraint; got: %v", v.Name, v.Rule))
}
switch v.Name {
case ExclusiveMinimum:
if f <= r {
return createError(x, v, fmt.Sprintf("value must be greater than %v", r))
}
case ExclusiveMaximum:
if f >= r {
return createError(x, v, fmt.Sprintf("value must be less than %v", r))
}
case InclusiveMinimum:
if f < r {
return createError(x, v, fmt.Sprintf("value must be greater than or equal to %v", r))
}
case InclusiveMaximum:
if f > r {
return createError(x, v, fmt.Sprintf("value must be less than or equal to %v", r))
}
default:
return createError(x, v, fmt.Sprintf("constraint %s is not applicable for type float", v.Name))
}
return nil
}
func validateString(x reflect.Value, v Constraint) error {
s := x.String()
switch v.Name {
case Empty:
if len(s) == 0 {
return checkEmpty(x, v)
}
case Pattern:
reg, err := regexp.Compile(v.Rule.(string))
if err != nil {
return createError(x, v, err.Error())
}
if !reg.MatchString(s) {
return createError(x, v, fmt.Sprintf("value doesn't match pattern %v", v.Rule))
}
case MaxLength:
if _, ok := v.Rule.(int); !ok {
return createError(x, v, fmt.Sprintf("rule must be integer value for %v constraint; got: %v", v.Name, v.Rule))
}
if len(s) > v.Rule.(int) {
return createError(x, v, fmt.Sprintf("value length must be less than or equal to %v", v.Rule))
}
case MinLength:
if _, ok := v.Rule.(int); !ok {
return createError(x, v, fmt.Sprintf("rule must be integer value for %v constraint; got: %v", v.Name, v.Rule))
}
if len(s) < v.Rule.(int) {
return createError(x, v, fmt.Sprintf("value length must be greater than or equal to %v", v.Rule))
}
case ReadOnly:
if len(s) > 0 {
return createError(reflect.ValueOf(s), v, "readonly parameter; must send as nil or empty in request")
}
default:
return createError(x, v, fmt.Sprintf("constraint %s is not applicable to string type", v.Name))
}
if v.Chain != nil {
return Validate([]Validation{
{
TargetValue: getInterfaceValue(x),
Constraints: v.Chain,
},
})
}
return nil
}
func validateArrayMap(x reflect.Value, v Constraint) error {
switch v.Name {
case Null:
if x.IsNil() {
return checkNil(x, v)
}
case Empty:
if x.IsNil() || x.Len() == 0 {
return checkEmpty(x, v)
}
case MaxItems:
if _, ok := v.Rule.(int); !ok {
return createError(x, v, fmt.Sprintf("rule must be integer for %v constraint; got: %v", v.Name, v.Rule))
}
if x.Len() > v.Rule.(int) {
return createError(x, v, fmt.Sprintf("maximum item limit is %v; got: %v", v.Rule, x.Len()))
}
case MinItems:
if _, ok := v.Rule.(int); !ok {
return createError(x, v, fmt.Sprintf("rule must be integer for %v constraint; got: %v", v.Name, v.Rule))
}
if x.Len() < v.Rule.(int) {
return createError(x, v, fmt.Sprintf("minimum item limit is %v; got: %v", v.Rule, x.Len()))
}
case UniqueItems:
if x.Kind() == reflect.Array || x.Kind() == reflect.Slice {
if !checkForUniqueInArray(x) {
return createError(x, v, fmt.Sprintf("all items in parameter %q must be unique; got:%v", v.Target, x))
}
} else if x.Kind() == reflect.Map {
if !checkForUniqueInMap(x) {
return createError(x, v, fmt.Sprintf("all items in parameter %q must be unique; got:%v", v.Target, x))
}
} else {
return createError(x, v, fmt.Sprintf("type must be array, slice or map for constraint %v; got: %v", v.Name, x.Kind()))
}
case ReadOnly:
if x.Len() != 0 {
return createError(x, v, "readonly parameter; must send as nil or empty in request")
}
case Pattern:
reg, err := regexp.Compile(v.Rule.(string))
if err != nil {
return createError(x, v, err.Error())
}
keys := x.MapKeys()
for _, k := range keys {
if !reg.MatchString(k.String()) {
return createError(k, v, fmt.Sprintf("map key doesn't match pattern %v", v.Rule))
}
}
default:
return createError(x, v, fmt.Sprintf("constraint %v is not applicable to array, slice and map type", v.Name))
}
if v.Chain != nil {
return Validate([]Validation{
{
TargetValue: getInterfaceValue(x),
Constraints: v.Chain,
},
})
}
return nil
}
func checkNil(x reflect.Value, v Constraint) error {
if _, ok := v.Rule.(bool); !ok {
return createError(x, v, fmt.Sprintf("rule must be bool value for %v constraint; got: %v", v.Name, v.Rule))
}
if v.Rule.(bool) {
return createError(x, v, "value can not be null; required parameter")
}
return nil
}
func checkEmpty(x reflect.Value, v Constraint) error {
if _, ok := v.Rule.(bool); !ok {
return createError(x, v, fmt.Sprintf("rule must be bool value for %v constraint; got: %v", v.Name, v.Rule))
}
if v.Rule.(bool) {
return createError(x, v, "value can not be null or empty; required parameter")
}
return nil
}
func checkForUniqueInArray(x reflect.Value) bool {
if x == reflect.Zero(reflect.TypeOf(x)) || x.Len() == 0 {
return false
}
arrOfInterface := make([]interface{}, x.Len())
for i := 0; i < x.Len(); i++ {
arrOfInterface[i] = x.Index(i).Interface()
}
m := make(map[interface{}]bool)
for _, val := range arrOfInterface {
if m[val] {
return false
}
m[val] = true
}
return true
}
func checkForUniqueInMap(x reflect.Value) bool {
if x == reflect.Zero(reflect.TypeOf(x)) || x.Len() == 0 {
return false
}
mapOfInterface := make(map[interface{}]interface{}, x.Len())
keys := x.MapKeys()
for _, k := range keys {
mapOfInterface[k.Interface()] = x.MapIndex(k).Interface()
}
m := make(map[interface{}]bool)
for _, val := range mapOfInterface {
if m[val] {
return false
}
m[val] = true
}
return true
}
func getInterfaceValue(x reflect.Value) interface{} {
if x.Kind() == reflect.Invalid {
return nil
}
return x.Interface()
}
func isZero(x interface{}) bool {
return x == reflect.Zero(reflect.TypeOf(x)).Interface()
}
func createError(x reflect.Value, v Constraint, err string) error {
return fmt.Errorf("autorest/validation: validation failed: parameter=%s constraint=%s value=%#v details: %s",
v.Target, v.Name, getInterfaceValue(x), err)
}
func toInt64(v interface{}) (int64, bool) {
if i64, ok := v.(int64); ok {
return i64, true
}
// older generators emit max constants as int, so if int64 fails fall back to int
if i32, ok := v.(int); ok {
return int64(i32), true
}
return 0, false
}