define-properties
Advanced tools
- Version published
- Maintainers
- 1
- Weekly downloads
- 36,925,375
- decreased by-4.44%
Weekly downloads
Package description
What is define-properties?
The define-properties npm package is used to define new properties on an object, including any necessary descriptors. It provides a simple API to define multiple properties at once while ensuring compatibility with older JavaScript engines that may not fully support ES5.
What are define-properties's main functionalities?
Defining multiple properties
This feature allows you to define multiple properties on an object with their descriptors. The 'enumerable' predicate ensures that the property will only be defined if the value is truthy.
{"object": {}, "properties": {"prop1": {"value": 42, "enumerable": true}, "prop2": {"value": 'hello', "enumerable": false}}, "predicates": {"enumerable": function(val) { return !!val; }}}Defining properties with shared descriptors
This feature allows you to define properties with a shared descriptor. The predicate function can be used to conditionally define properties based on the key or value.
{"object": {}, "propertyNames": ["prop1", "prop2"], "descriptor": {"enumerable": true}, "predicate": function(key, value) { return key === 'prop1' || value > 10; }}Other packages similar to define-properties
object-define-property
This package provides a similar functionality to define-properties by allowing you to define a new property directly on an object. It is a polyfill for Object.defineProperty and is useful for ensuring compatibility with older JavaScript engines.
es5-ext
es5-ext is a collection of ECMAScript 5 extensions, including various shims and polyfills. It offers a broader set of functionalities compared to define-properties, which includes defining properties but also other utilities for working with objects, arrays, and functions.
Changelog
v1.2.0 - 2023-02-10
Commits
- [New] if the predicate is boolean
true, it compares the existing value with===as the predicated8dd6fc - [meta] add
auto-changelog7ebe2b0 - [meta] use
npmignoreto autogenerate an npmignore file647478a - [Dev Deps] update
@ljharb/eslint-config,aud,tapee620d70 - [Dev Deps] update
aud,tapef1e5072 - [actions] update checkout action
628b3af
1.1.4 / 2022-04-14
- [Refactor] use
has-property-descriptors - [readme] add github actions/codecov badges
- [Docs] fix header parsing; remove testling
- [Deps] update
object-keys - [meta] use
prepublishOnlyscript for npm 7+ - [meta] add
fundingfield; create FUNDING.yml - [actions] add "Allow Edits" workflow; automatic rebasing / merge commit blocking
- [actions] reuse common workflows
- [actions] update codecov uploader
- [actions] use
node/installinstead ofnode/run; usecodecovaction - [Tests] migrate tests to Github Actions
- [Tests] run
nycon all tests; usetaperunner - [Tests] use shared travis-ci config
- [Tests] use
npx audinstead ofnspornpm auditwith hoops - [Tests] remove
jscs - [Dev Deps] update
eslint,@ljharb/eslint-config,safe-publish-latest,tape; addaud,safe-publish-latest
1.1.3 / 2018-08-14
- [Refactor] use a for loop instead of
foreachto make for smaller bundle sizes - [Robustness] cache
Array.prototype.concatandObject.defineProperty - [Deps] update
object-keys - [Dev Deps] update
eslint,@ljharb/eslint-config,nsp,tape,jscs; remove unused eccheck script + dep - [Tests] use pretest/posttest for linting/security
- [Tests] fix npm upgrades on older nodes
1.1.2 / 2015-10-14
- [Docs] Switch from vb.teelaun.ch to versionbadg.es for the npm version badge SVG
- [Deps] Update
object-keys - [Dev Deps] update
jscs,tape,eslint,@ljharb/eslint-config,nsp - [Tests] up to
io.jsv3.3,nodev4.2
1.1.1 / 2015-07-21
- [Deps] Update
object-keys - [Dev Deps] Update
tape,eslint - [Tests] Test on
io.jsv2.4
1.1.0 / 2015-07-01
- [New] Add support for symbol-valued properties.
- [Dev Deps] Update
nsp,eslint - [Tests] Test up to
io.jsv2.3
1.0.3 / 2015-05-30
- Using a more reliable check for supported property descriptors.
1.0.2 / 2015-05-23
- Test up to
io.jsv2.0 - Update
tape,jscs,nsp,eslint,object-keys,editorconfig-tools,covert
1.0.1 / 2015-01-06
- Update
object-keysto fix ES3 support
1.0.0 / 2015-01-04
- v1.0.0
Readme
define-properties 
Define multiple non-enumerable properties at once. Uses Object.defineProperty when available; falls back to standard assignment in older engines.
Existing properties are not overridden. Accepts a map of property names to a predicate that, when true, force-overrides.
Example
var define = require('define-properties');
var assert = require('assert');
var obj = define({ a: 1, b: 2 }, {
a: 10,
b: 20,
c: 30
});
assert(obj.a === 1);
assert(obj.b === 2);
assert(obj.c === 30);
if (define.supportsDescriptors) {
assert.deepEqual(Object.keys(obj), ['a', 'b']);
assert.deepEqual(Object.getOwnPropertyDescriptor(obj, 'c'), {
configurable: true,
enumerable: false,
value: 30,
writable: false
});
}
Then, with predicates:
var define = require('define-properties');
var assert = require('assert');
var obj = define({ a: 1, b: 2, c: 3 }, {
a: 10,
b: 20,
c: 30
}, {
a: function () { return false; },
b: function () { return true; }
});
assert(obj.a === 1);
assert(obj.b === 20);
assert(obj.c === 3);
if (define.supportsDescriptors) {
assert.deepEqual(Object.keys(obj), ['a', 'c']);
assert.deepEqual(Object.getOwnPropertyDescriptor(obj, 'b'), {
configurable: true,
enumerable: false,
value: 20,
writable: false
});
}
Tests
Simply clone the repo, npm install, and run npm test
FAQs
Define multiple non-enumerable properties at once. Uses `Object.defineProperty` when available; falls back to standard assignment in older engines.
The npm package define-properties receives a total of 35,015,926 weekly downloads. As such, define-properties popularity was classified as popular.
We found that define-properties demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 1 open source maintainer collaborating on the project.
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