node.js – 轮询URL直到在JSON响应中设置某个值：Mocha,Integration testing

const request = require('request');

describe('example',() => {
    it('polling',function (donE) {
        this.timeout(5000);

        let attemptsLeft = 10;
        const expectedValue = '42';
        const delaybetweenrequest = 100;

        function check() {
            request('http://www.google.com',(error,response,body) => {
                if (body === expectedvalue) return done();
                attemptsLeft -= 1;
                if (!attemptsLeft) return done(new Error('All attempts used'));
                setTimeout(check,delaybetweenrequest);
            });
        }

        check();
    });
});

got和async / await方法的示例：

const utils = require('util');
const got = require('got');

const wait = utils.promisify(setTimeout);

describe('example',async function (donE) {
        this.timeout(5000);
        const expectedValue = '42';
        const delaybetweenrequest = 100;

        for (let attemptsLeft = 10; attemptsLeft; attemptsLeft -= 1) {
            const resp = await got.get('http://www.google.com');
            if (resp.body === expectedvalue) return done();
            await wait(delaybetweenrequest);
        }

        done(new Error('All attempts used'));
    });
});