isNonEnumerablePropertyIn

Test if an object's own or inherited property is non-enumerable.

Usage

var isNonEnumerablePropertyIn = require( '@stdlib/assert/is-nonenumerable-property-in' );

isNonEnumerablePropertyIn( value, property )

Returns a boolean indicating if a value has a non-enumerable property.

var defineProperty = require( '@stdlib/utils/define-property' );

var bool;
var obj;

function Foo() {
    this.foo = 'bar';
    return this;
}

defineProperty( Foo.prototype, 'beep', {
    'configurable': true,
    'enumerable': true,
    'writable': true,
    'value': true
});

defineProperty( Foo.prototype, 'boop', {
    'configurable': true,
    'enumerable': false,
    'writable': true,
    'value': true
});

obj = new Foo();

bool = isNonEnumerablePropertyIn( obj, 'foo' );
// returns false

bool = isNonEnumerablePropertyIn( obj, 'beep' );
// returns false

bool = isNonEnumerablePropertyIn( obj, 'boop' );
// returns true

Notes

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

    var bool = isNonEnumerablePropertyIn( 'beep', 'length' );
    // returns true
    
  • Non-symbol property arguments are coerced to strings.

    var defineProperty = require( '@stdlib/utils/define-property' );
    
    var obj = {};
    
    defineProperty( obj, 'null', {
        'configurable': true,
        'enumerable': false,
        'writable': true,
        'value': true
    });
    
    var bool = isNonEnumerablePropertyIn( obj, null );
    // returns true
    

Examples

var isNonEnumerablePropertyIn = require( '@stdlib/assert/is-nonenumerable-property-in' );

var bool = isNonEnumerablePropertyIn( {}, 'toString' );
// returns true

bool = isNonEnumerablePropertyIn( {}, 'hasOwnProperty' );
// returns true

bool = isNonEnumerablePropertyIn( [ 'a' ], 'length' );
// returns true

bool = isNonEnumerablePropertyIn( { 'a': 'b' }, 'a' );
// returns false

bool = isNonEnumerablePropertyIn( [ 'a' ], 0 );
// returns false

bool = isNonEnumerablePropertyIn( { 'null': false }, null );
// returns false

bool = isNonEnumerablePropertyIn( { '[object Object]': false }, {} );
// returns false

bool = isNonEnumerablePropertyIn( null, 'a' );
// returns false

bool = isNonEnumerablePropertyIn( void 0, 'a' );
// returns false
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