es-to-primitive

What is es-to-primitive?

The es-to-primitive npm package provides functionality to convert a JavaScript value to its primitive equivalent, following the ECMAScript specification for ToPrimitive abstract operation. It handles the conversion according to the preferred type hint, either Number or String.

What are es-to-primitive's main functionalities?

Converting to primitive with no hint

This code converts a Date object to its primitive value without specifying a type hint. The default hint will be applied based on the object type.

var toPrimitive = require('es-to-primitive');
var obj = new Date();
var primitiveValue = toPrimitive(obj);

Converting to primitive with a hint of Number

This code converts a Date object to its primitive value with a type hint of Number, which means it will prefer the numeric value of the Date (timestamp).

var toPrimitive = require('es-to-primitive');
var obj = new Date();
var primitiveValue = toPrimitive(obj, Number);

Converting to primitive with a hint of String

This code converts an object with both toString and valueOf methods to its primitive value with a type hint of String, which means it will prefer the string representation 'foo'.

var toPrimitive = require('es-to-primitive');
var obj = { toString: function() { return 'foo'; }, valueOf: function() { return 42; } };
var primitiveValue = toPrimitive(obj, String);

Other packages similar to es-to-primitive

to-primitive

The to-primitive package is another alternative that offers similar functionality to es-to-primitive. It aims to provide a reliable way to get the primitive value of objects but may have different internal implementations or API design.

README

es-to-primitive

ECMAScript “ToPrimitive” algorithm. Provides ES5 and ES2015 versions. When different versions of the spec conflict, the default export will be the latest version of the abstract operation. Alternative versions will also be available under an es5/es2015 exported property if you require a specific version.

Example

var toPrimitive = require('es-to-primitive');
var assert = require('assert');

assert(toPrimitive(function () {}) === String(function () {}));

var date = new Date();
assert(toPrimitive(date) === String(date));

assert(toPrimitive({ valueOf: function () { return 3; } }) === 3);

assert(toPrimitive(['a', 'b', 3]) === String(['a', 'b', 3]));

var sym = Symbol();
assert(toPrimitive(Object(sym)) === sym);

Tests

Simply clone the repo, npm install, and run npm test