es-shim-unscopables 
Helper package to shim a method into Array.prototype[Symbol.unscopables]
Example
const assert = require('assert');
const shimUnscopables = require('es-shim-unscopables');
let copyWithin;
let concat;
with ([]) {
assert.equal(concat, Array.prototype.concat);
assert.notEqual(copyWithin, Array.prototype.copyWithin);
}
shimUnscopables('concat');
with ([]) {
assert.notEqual(concat, Array.prototype.concat);
assert.notEqual(copyWithin, Array.prototype.copyWithin);
}Tests
Simply clone the repo, npm install, and run npm test
Security
Please email @ljharb or see https://tidelift.com/security if you have a potential security vulnerability to report.