is-data-descriptor

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

Install

Install with npm:

$ npm i is-data-descriptor --save

Usage

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

Examples

true when the descriptor has valid properties with valid values.

// `value` can be anything
isDataDesc({value: 'foo'})
isDataDesc({value: function() {}})
isDataDesc({value: true})
//=> true

false when not an object

isDataDesc('a')
//=> false
isDataDesc(null)
//=> false
isDataDesc([])
//=> false

false when the object has invalid properties

isDataDesc({value: 'foo', bar: 'baz'})
//=> false
isDataDesc({value: 'foo', bar: 'baz'})
//=> false
isDataDesc({value: 'foo', get: function(){}})
//=> false
isDataDesc({get: function(){}, value: 'foo'})
//=> false

false when a value is not the correct type

isDataDesc({value: 'foo', enumerable: 'foo'})
//=> false
isDataDesc({value: 'foo', configurable: 'foo'})
//=> false
isDataDesc({value: 'foo', writable: 'foo'})
//=> false

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).

var foo = {};

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

console.log(foo.bar);
//=> 'baz'

is-accessor-descriptor: Returns true if a value has the characteristics of a valid JavaScript accessor 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

Running tests

Install dev dependencies:

$ npm i -d && npm test

Contributing

Pull requests and stars are always welcome. For bugs and feature requests, please create an issue.

Author

Jon Schlinkert

License

This file was generated by verb on December 28, 2015.

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