Random name generator in javascript using iterators

RandomNameGenerator.js

export default class RandomNameGenerator {
    constructor(amountOfNames, lengthOfNames) {
        this.amountOfNames = amountOfNames;
        this.lengthOfNames = lengthOfNames;
        this.names = new Array();
    };
    makeName(stringLength) {
        let result           = '';
        const characters       = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
        const charactersLength = characters.length;
        for (let i = 0; i < stringLength; i++ ) {
           result += characters.charAt(Math.floor(Math.random() * charactersLength));
        }
        return result;
    }
    *[Symbol.iterator]() {
        while(this.names.length < this.amountOfNames) {
            let newName;
            do {
                newName = this.makeName(this.lengthOfNames);
                this.names.push(newName);
            } while (this.names.indexOf(newName) === -1);
            yield newName;
        }
    }
}

// Example of usage
// console.log([...new RandomNameGenerator(5, 15)]); // 5 random names with length of 15