is-data-descriptor
    DefinitelyTyped icon, indicating that this package has TypeScript declarations provided by the separate @types/is-data-descriptor package

    2.0.0 • Public • Published

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

    Please consider following this project's author, Jon Schlinkert, and consider starring the project to show your ❤️ and support.

    Install

    Install with npm:

    $ npm install --save is-data-descriptor

    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'

    About

    Contributing

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

    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
    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

    Related projects

    You might also be interested in these projects:

    Contributors

    Commits Contributor
    21 jonschlinkert
    2 realityking

    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 November 01, 2017.

    Install

    npm i is-data-descriptor

    DownloadsWeekly Downloads

    49,401,331

    Version

    2.0.0

    License

    MIT

    Unpacked Size

    8.71 kB

    Total Files

    4

    Last publish

    Collaborators

    • jonschlinkert