String.prototype.trimLeft 
A spec-proposal-compliant String.prototype.trimLeft shim. Invoke its "shim" method to shim String.prototype.trimLeft if it is unavailable.
This package implements the es-shim API interface. It works in an ES3-supported environment and complies with the spec. In an ES6 environment, it will also work properly with Symbols.
Most common usage:
var trimLeft = require('string.prototype.trimleft');
assert(trimLeft(' \t\na \t\n') === 'a \t\n');
if (!String.prototype.trimLeft) {
trimLeft.shim();
}
assert(trimLeft(' \t\na \t\n') === ' \t\na \t\n'.trimLeft());
Tests
Simply clone the repo, npm install, and run npm test