@stdlib/assert-is-nonconfigurable-property

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isNonConfigurableProperty

Test if an object's own property is non-configurable.

Installation

npm install @stdlib/assert-is-nonconfigurable-property

Usage

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).

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

Notes

• Value arguments other than null or undefined are coerced to objects.

  var bool = isNonConfigurableProperty( 'beep', 'length' );
  // returns true
  

Examples

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

See Also

• @stdlib/assert-is-configurable-property: test if an object's own property is configurable.
• @stdlib/assert-is-enumerable-property: test if an object's own property is enumerable.
• @stdlib/assert-is-nonconfigurable-property-in: test if an object's own or inherited property is non-configurable.
• @stdlib/assert-is-nonenumerable-property: test if an object's own property is non-enumerable.
• @stdlib/assert-is-readable-property: test if an object's own property is readable.
• @stdlib/assert-is-writable-property: test if an object's own property is writable.

Notice

This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.

Community

License

See LICENSE.

Copyright

Copyright © 2016-2026. The Stdlib Authors.