recaptcha.js

    /**
     * @param {Express.Request} request
     * @param {Express.Response} response
     */
    async testRecaptcha(request, response) {
        /** @type {String} */
        const captcha = request.allParams().recaptchaToken;

        // check assumptions, or crash
        Preconditions.shouldBeNonBlankString(captcha, 'missing: params.recaptchaToken');
        
        /** @type {{ success:boolean, challenge_ts:String }} */
        const value = await RequestPromise({
                    url: 'https://www.google.com/recaptcha/api/siteverify',
                    method: 'GET',
                    json: true,
                    qs: { // qs = query string
                        secret: Preconditions.shouldBeNonBlankString(sails.config.coinme.recaptcha.secretKey),
                        response: Preconditions.shouldBeNonBlankString(captcha),
                        remoteip: ControllerService.getRemoteHost(request)
                    }
                });
        
        // check the assumptions
        Preconditions.shouldBeObject(value, 'unknown dependency error');
        Preconditions.shouldBeTrue(value.success, 'incorrect recaptcha');

        /** @type {Date} */
        const date = Preconditions.shouldBeDate(Utility.optDate(value.challenge_ts));

        // make sure not too old; 600 seconds = 10 mins
        Preconditions.shouldBeFalsey(Utility.getAgeInSeconds(date) > 600, 'should be within 10 minutes');
        
        // TODO: parse the timestamp '2017-01-17T03:08:41Z'

        // {
        //     "success": true|false,
        //     "challenge_ts": timestamp,  // timestamp of the challenge load (ISO format yyyy-MM-dd'T'HH:mm:ssZZ)
        //     "hostname": string,         // the hostname of the site where the reCAPTCHA was solved
        //     "error-codes": [...]        // optional
        // }

        return ControllerService.setRecentRecaptcha(request, response);
    },