Get and robustly cache all JS language-level intrinsics at first require time.
See the syntax described in the JS spec for reference.
var GetIntrinsic = require('get-intrinsic'); var assert = require('assert'); // static methods assert.equal(GetIntrinsic('%Math.pow%'), Math.pow); assert.equal(Math.pow(2, 3), 8); assert.equal(GetIntrinsic('%Math.pow%')(2, 3), 8); delete Math.pow; assert.equal(GetIntrinsic('%Math.pow%')(2, 3), 8); // instance methods var arr = [1]; assert.equal(GetIntrinsic('%Array.prototype.push%'), Array.prototype.push); assert.deepEqual(arr, [1]); arr.push(2); assert.deepEqual(arr, [1, 2]); GetIntrinsic('%Array.prototype.push%').call(arr, 3); assert.deepEqual(arr, [1, 2, 3]); delete Array.prototype.push; GetIntrinsic('%Array.prototype.push%').call(arr, 4); assert.deepEqual(arr, [1, 2, 3, 4]); // missing features delete JSON.parse; // to simulate a real intrinsic that is missing in the environment assert.throws(() => GetIntrinsic('%JSON.parse%')); assert.equal(undefined, GetIntrinsic('%JSON.parse%', true));
Simply clone the repo, npm install
, and run npm test
Please email @ljharb or see https://tidelift.com/security if you have a potential security vulnerability to report.