5.7 KiB
is-descriptor 
Returns true if a value has the characteristics of a valid JavaScript descriptor. Works for data descriptors and accessor descriptors.
Install
Install with npm:
$ npm install --save is-descriptor
Usage
var isDescriptor = require('is-descriptor');
isDescriptor({value: 'foo'})
//=> true
isDescriptor({get: function(){}, set: function(){}})
//=> true
isDescriptor({get: 'foo', set: function(){}})
//=> false
You may also check for a descriptor by passing an object as the first argument and property name (string) as the second argument.
var obj = {};
obj.foo = 'abc';
Object.defineProperty(obj, 'bar', {
value: 'xyz'
});
isDescriptor(obj, 'foo');
//=> true
isDescriptor(obj, 'bar');
//=> true
Examples
value type
false when not an object
isDescriptor('a');
//=> false
isDescriptor(null);
//=> false
isDescriptor([]);
//=> false
data descriptor
true when the object has valid properties with valid values.
isDescriptor({value: 'foo'});
//=> true
isDescriptor({value: noop});
//=> true
false when the object has invalid properties
isDescriptor({value: 'foo', bar: 'baz'});
//=> false
isDescriptor({value: 'foo', bar: 'baz'});
//=> false
isDescriptor({value: 'foo', get: noop});
//=> false
isDescriptor({get: noop, value: noop});
//=> false
false when a value is not the correct type
isDescriptor({value: 'foo', enumerable: 'foo'});
//=> false
isDescriptor({value: 'foo', configurable: 'foo'});
//=> false
isDescriptor({value: 'foo', writable: 'foo'});
//=> false
accessor descriptor
true when the object has valid properties with valid values.
isDescriptor({get: noop, set: noop});
//=> true
isDescriptor({get: noop});
//=> true
isDescriptor({set: noop});
//=> true
false when the object has invalid properties
isDescriptor({get: noop, set: noop, bar: 'baz'});
//=> false
isDescriptor({get: noop, writable: true});
//=> false
isDescriptor({get: noop, value: true});
//=> false
false when an accessor is not a function
isDescriptor({get: noop, set: 'baz'});
//=> false
isDescriptor({get: 'foo', set: noop});
//=> false
isDescriptor({get: 'foo', bar: 'baz'});
//=> false
isDescriptor({get: 'foo', set: 'baz'});
//=> false
false when a value is not the correct type
isDescriptor({get: noop, set: noop, enumerable: 'foo'});
//=> false
isDescriptor({set: noop, configurable: 'foo'});
//=> false
isDescriptor({get: noop, configurable: 'foo'});
//=> false
About
Related projects
- is-accessor-descriptor: Returns true if a value has the characteristics of a valid JavaScript accessor descriptor. | homepage
- is-data-descriptor: Returns true if a value has the characteristics of a valid JavaScript data descriptor. | homepage
- is-descriptor: Returns true if a value has the characteristics of a valid JavaScript descriptor. Works for… more | homepage
- isobject: Returns true if the value is an object and not an array or null. | homepage
Contributing
Pull requests and stars are always welcome. For bugs and feature requests, please create an issue.
Contributors
| Commits | Contributor |
|---|---|
| 24 | jonschlinkert |
| 1 | doowb |
| 1 | wtgtybhertgeghgtwtg |
Building docs
(This project's readme.md is generated by verb, please don't edit the readme directly. Any changes to the readme must be made in the .verb.md readme template.)
To generate the readme, run the following command:
$ npm install -g verbose/verb#dev verb-generate-readme && verb
Running tests
Running and reviewing unit tests is a great way to get familiarized with a library and its API. You can install dependencies and run tests with the following command:
$ npm install && npm test
Author
Jon Schlinkert
License
Copyright © 2017, Jon Schlinkert. Released under the MIT License.
This file was generated by verb-generate-readme, v0.6.0, on July 22, 2017.