https://github.com/ljharb/define-accessor-property
Define an accessor property on an object. Will either throw, or fall back to assignment in loose mode, in an engine without descriptors.
https://github.com/ljharb/define-accessor-property
accessor define descriptors get getter property set setter
Last synced: 6 months ago
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Define an accessor property on an object. Will either throw, or fall back to assignment in loose mode, in an engine without descriptors.
- Host: GitHub
- URL: https://github.com/ljharb/define-accessor-property
- Owner: ljharb
- License: mit
- Created: 2024-02-12T17:49:26.000Z (over 1 year ago)
- Default Branch: main
- Last Pushed: 2024-03-09T06:31:04.000Z (over 1 year ago)
- Last Synced: 2025-01-08T17:07:02.252Z (6 months ago)
- Topics: accessor, define, descriptors, get, getter, property, set, setter
- Language: JavaScript
- Homepage:
- Size: 17.6 KB
- Stars: 3
- Watchers: 2
- Forks: 0
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- Funding: .github/FUNDING.yml
- License: LICENSE
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README
# define-accessor-property [![Version Badge][npm-version-svg]][package-url]
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Define an accessor property on an object. In an engine without descriptors, in loose mode, when only a getter is provided, nonEnumerable is false, and nonConfigurable is false, wil fall back to assignment - otherwise, it will throw.
The two `non*` options can also be passed `null`, which will use the existing state if available.
The `loose` option will mean that if you attempt to set a nonconfigurable/nonwritable accessor property with `set`, in an environment without descriptor support, it will fall back to normal assignment (and eagerly evaluate the getter).
## Usage
```javascript
var defineAccessorProperty = require('define-accessor-property');
var assert = require('assert');
var str = 'value';
var strThunk = function () { return str; };
var strSetter = function (v) { str = v; };
var random = function () { return Math.random(); };
var obj = {};
defineAccessorProperty(
obj,
'key',
{
get: strThunk,
set: strSetter,
}
);
defineAccessorProperty(
obj,
'key2',
{
get: random, // at least one of "get" or "set" must be provided
nonConfigurable: true, // optional
nonEnumerable: true, // optional
loose: false, // optional
}
);
assert.deepEqual(
Object.getOwnPropertyDescriptors(obj),
{
key: {
configurable: true,
enumerable: true,
get: strThunk,
set: strSetter,
},
key2: {
configurable: false,
enumerable: false,
get: random,
set: undefined,
},
}
);
```
[package-url]: https://npmjs.org/package/define-accessor-property
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[license-url]: LICENSE
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