jointjs/src/polyfills/string.js

JavaScript diagramming library

if (!String.prototype.includes) {
    String.prototype.includes = function(search, start) {
        'use strict';
        if (typeof start !== 'number') {
            start = 0;
        }

        if (start + search.length > this.length) {
            return false;
        } else {
            return this.indexOf(search, start) !== -1;
        }
    };
}

if (!String.prototype.startsWith) {
    String.prototype.startsWith = function(searchString, position){
        return this.substr(position || 0, searchString.length) === searchString;
    };
}