A simple counting plugin for the Chai assertion library. expect(n).to.be.zero, expect(n).to.be.one, and so on, through expect(n).to.be.ten. Alternatively, n.should.be.zero, n.should.be.one, etc. This saves you the agony of typing the parentheses in n.should.be.eq(0);.

npm install chai-counting

const chai = require('chai');
const chaiCounting = require('chai-counting');
chai.use(chaiCounting);