isReadOnlyProperty

Test if an object's own property is read-only.

Usage

var isReadOnlyProperty = require( '@stdlib/assert/is-read-only-property' );

isReadOnlyProperty( value, property )

Returns a boolean indicating if a value has a read-only property.

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

var obj = {
    'foo': 'bar'
};

defineProperty( obj, 'beep', {
    'configurable': false,
    'enumerable': false,
    'writable': false,
    'value': 'boop'
});

defineProperty( obj, 'accessor', {
    'configurable': false,
    'enumerable': true,
    'get': function getter() {
        return obj.foo;
    }
});

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

bool = isReadOnlyProperty( obj, 'beep' );
// returns true

bool = isReadOnlyProperty( obj, 'accessor' );
// returns true

Notes

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

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

Property arguments are coerced to strings.

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

var obj = {};

defineProperty( obj, 'null', {
    'configurable': false,
    'enumerable': true,
    'writable': false,
    'value': true
});

var bool = isReadOnlyProperty( obj, null );
// returns true

Examples

var isReadOnlyProperty = require( '@stdlib/assert/is-read-only-property' );

var bool = isReadOnlyProperty( 'a', 'length' );
// returns true

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

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

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

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

bool = isReadOnlyProperty( {}, 'toString' );
// returns false

bool = isReadOnlyProperty( {}, 'hasOwnProperty' );
// returns false

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

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