is-data-descriptor ^{[![Version Badge][npm-version-svg]][package-url]}

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> Returns true if a value has the characteristics of a valid JavaScript data descriptor.

Examples

true when the descriptor has valid properties with valid values.
false when not an object or when the object has invalid properties.

``js
var isDataDesc = require('is-data-descriptor');
var assert = require('assert');

assert.equal(true, isDataDesc({ value: 'foo' }));
assert.equal(true, isDataDesc({ value: function () {} }));
assert.equal(true, isDataDesc({ value: true }));

assert.equal(false, isDataDesc('a'));
assert.equal(false, isDataDesc(null));
assert.equal(false, isDataDesc([]));

assert.equal(false, isDataDesc({ value: 'foo', bar: 'baz' }));
assert.equal(false, isDataDesc({ value: 'foo', bar: 'baz' }));
assert.equal(false, isDataDesc({ value: 'foo', get: function () {} }));
assert.equal(false, isDataDesc({ get: function () {}, value: 'foo' }) );

assert.equal(false, isDataDesc({ value: 'foo', enumerable: 'foo' }));
assert.equal(false, isDataDesc({ value: 'foo', configurable: 'foo' }));
assert.equal(false, isDataDesc({ value: 'foo', writable: 'foo' }));
`

Valid properties

The only valid data descriptor properties are the following:

* configurable (required)
* enumerable (required)
* value (optional)
* writable (optional)

To be a valid data descriptor, either value or writable must be defined.

Invalid properties

A descriptor may have additional _invalid_ properties (an error will not be thrown).

`js
var foo = {};

Object.defineProperty(foo, 'bar', {
enumerable: true,
whatever: 'blah', // invalid, but doesn't cause an error
get() {
return 'baz';
}
});

assert.equal(foo.bar, 'baz');
`

$3

* is-accessor-descriptor: Returns true if a value has the characteristics of a valid JavaScript accessor descriptor.
* is-descriptor: Returns true if a value has the characteristics of a valid JavaScript descriptor. Works for… more

Tests

Simply clone the repo, npm install, and run npm test`

[package-url]: https://npmjs.org/package/is-data-descriptor
[npm-version-svg]: https://versionbadg.es/inspect-js/is-data-descriptor.svg
[deps-svg]: https://david-dm.org/inspect-js/is-data-descriptor.svg
[deps-url]: https://david-dm.org/inspect-js/is-data-descriptor
[dev-deps-svg]: https://david-dm.org/inspect-js/is-data-descriptor/dev-status.svg
[dev-deps-url]: https://david-dm.org/inspect-js/is-data-descriptor#info=devDependencies
[npm-badge-png]: https://nodei.co/npm/is-data-descriptor.png?downloads=true&stars=true
[license-image]: https://img.shields.io/npm/l/is-data-descriptor.svg
[license-url]: LICENSE
[downloads-image]: https://img.shields.io/npm/dm/is-data-descriptor.svg
[downloads-url]: https://npm-stat.com/charts.html?package=is-data-descriptor
[codecov-image]: https://codecov.io/gh/inspect-js/is-data-descriptor/branch/main/graphs/badge.svg
[codecov-url]: https://app.codecov.io/gh/inspect-js/is-data-descriptor/
[actions-image]: https://img.shields.io/endpoint?url=https://github-actions-badge-u3jn4tfpocch.runkit.sh/inspect-js/is-data-descriptor
[actions-url]: https://github.com/inspect-js/is-data-descriptor/actions