<!-- @license Apache-2.0 Copyright (c) 2018 The Stdlib Authors. 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. --> # isNonConfigurableProperty > Test if an object's own property is non-configurable. <section class="usage"> ## Usage ```javascript var isNonConfigurableProperty = require( '@stdlib/assert/is-nonconfigurable-property' ); ``` #### isNonConfigurableProperty( value, property ) Returns a `boolean` indicating if a `value` has a non-configurable `property` (i.e., a property which cannot be deleted and whose descriptor cannot be changed). ```javascript var defineProperty = require( '@stdlib/utils/define-property' ); var obj = { 'foo': 'bar' }; defineProperty( obj, 'beep', { 'configurable': false, 'enumerable': true, 'writable': true, 'value': 'boop' }); var bool = isNonConfigurableProperty( obj, 'beep' ); // returns true bool = isNonConfigurableProperty( obj, 'foo' ); // returns false ``` </section> <!-- /.usage --> <section class="notes"> ## Notes - Value arguments other than `null` or `undefined` are coerced to `objects`. ```javascript var bool = isNonConfigurableProperty( 'beep', 'length' ); // returns true ``` </section> <!-- /.notes --> <section class="examples"> ## Examples <!-- eslint-disable object-curly-newline --> <!-- eslint no-undef: "error" --> ```javascript var isNonConfigurableProperty = require( '@stdlib/assert/is-nonconfigurable-property' ); var bool = isNonConfigurableProperty( [ 'a' ], 'length' ); // returns true bool = isNonConfigurableProperty( { 'a': 'b' }, 'a' ); // returns false bool = isNonConfigurableProperty( [ 'a' ], 0 ); // returns false bool = isNonConfigurableProperty( {}, 'toString' ); // returns false bool = isNonConfigurableProperty( {}, 'hasOwnProperty' ); // returns false bool = isNonConfigurableProperty( null, 'a' ); // returns false bool = isNonConfigurableProperty( void 0, 'a' ); // returns false bool = isNonConfigurableProperty( { 'null': false }, null ); // returns false bool = isNonConfigurableProperty( { '[object Object]': false }, {} ); // returns false ``` </section> <!-- /.examples --> <section class="links"> </section> <!-- /.links -->