String.prototype.trimStart 

An ES2019-spec-compliant String.prototype.trimStart shim. Invoke its "shim" method to shim String.prototype.trimStart 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 trimStart = require('string.prototype.trimstart');

assert(trimStart(' \t\na \t\n') === 'a \t\n');

if (!String.prototype.trimStart) {
    trimStart.shim();
}

assert(trimStart(' \t\na \t\n') === ' \t\na \t\n'.trimStart());

Tests

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