README.md

set.prototype.difference

ES Proposal spec-compliant shim for Set.prototype.difference. Invoke its "shim" method to shim Set.prototype.difference if it is unavailable or noncompliant.

This package implements the es-shim API interface. It works in an ES3-supported environment, and complies with the proposed spec. When shimmed, it uses es-set to shim the Set implementation itself if needed.

Most common usage:

var assert = require('assert');
var difference = require('set.prototype.difference');

var set1 = new Set([1, 2]);
var set2 = new Set([2, 3]);
var result = difference(set1, set2);

assert.deepEqual(result, new Set([1]));

difference.shim();

var shimmedResult = set1.difference(set2);
assert.deepEqual(shimmedResult, new Set([1]));

Compatibility

node v22 and equivalent versions of Chrome have Set difference, but has a bug with set-like arguments with non-SMI integer sizes.

Tests

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

Set Method Packages

• union
• intersection
• difference
• symmetricDifference
• isSubsetOf
• isSupersetOf
• isDisjointFrom