mirror of
https://github.com/actions/setup-python.git
synced 2024-11-23 00:49:39 +00:00
128 lines
No EOL
3.2 KiB
Markdown
128 lines
No EOL
3.2 KiB
Markdown
# is-data-descriptor [](https://www.npmjs.com/package/is-data-descriptor) [](https://travis-ci.org/jonschlinkert/is-data-descriptor)
|
|
|
|
> Returns true if a value has the characteristics of a valid JavaScript data descriptor.
|
|
|
|
## Install
|
|
|
|
Install with [npm](https://www.npmjs.com/):
|
|
|
|
```sh
|
|
$ npm i is-data-descriptor --save
|
|
```
|
|
|
|
## Usage
|
|
|
|
```js
|
|
var isDataDesc = require('is-data-descriptor');
|
|
```
|
|
|
|
## Examples
|
|
|
|
`true` when the descriptor has valid properties with valid values.
|
|
|
|
```js
|
|
// `value` can be anything
|
|
isDataDesc({value: 'foo'})
|
|
isDataDesc({value: function() {}})
|
|
isDataDesc({value: true})
|
|
//=> true
|
|
```
|
|
|
|
`false` when not an object
|
|
|
|
```js
|
|
isDataDesc('a')
|
|
//=> false
|
|
isDataDesc(null)
|
|
//=> false
|
|
isDataDesc([])
|
|
//=> false
|
|
```
|
|
|
|
`false` when the object has invalid properties
|
|
|
|
```js
|
|
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
|
|
|
|
```js
|
|
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).
|
|
|
|
```js
|
|
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'
|
|
```
|
|
|
|
## Related projects
|
|
|
|
* [is-accessor-descriptor](https://www.npmjs.com/package/is-accessor-descriptor): Returns true if a value has the characteristics of a valid JavaScript accessor descriptor. | [homepage](https://github.com/jonschlinkert/is-accessor-descriptor)
|
|
* [is-descriptor](https://www.npmjs.com/package/is-descriptor): Returns true if a value has the characteristics of a valid JavaScript descriptor. Works for… [more](https://www.npmjs.com/package/is-descriptor) | [homepage](https://github.com/jonschlinkert/is-descriptor)
|
|
* [isobject](https://www.npmjs.com/package/isobject): Returns true if the value is an object and not an array or null. | [homepage](https://github.com/jonschlinkert/isobject)
|
|
|
|
## Running tests
|
|
|
|
Install dev dependencies:
|
|
|
|
```sh
|
|
$ npm i -d && npm test
|
|
```
|
|
|
|
## Contributing
|
|
|
|
Pull requests and stars are always welcome. For bugs and feature requests, [please create an issue](https://github.com/jonschlinkert/is-data-descriptor/issues/new).
|
|
|
|
## Author
|
|
|
|
**Jon Schlinkert**
|
|
|
|
* [github/jonschlinkert](https://github.com/jonschlinkert)
|
|
* [twitter/jonschlinkert](http://twitter.com/jonschlinkert)
|
|
|
|
## License
|
|
|
|
Copyright © 2015 [Jon Schlinkert](https://github.com/jonschlinkert)
|
|
Released under the MIT license.
|
|
|
|
***
|
|
|
|
_This file was generated by [verb](https://github.com/verbose/verb) on December 28, 2015._ |