dbmedialab/reader-critics

//
// LESERKRITIKK v2 (aka Reader Critics)
// Copyright (C) 2017 DB Medialab/Aller Media AS, Oslo, Norway
// https://github.com/dbmedialab/reader-critics/
//
// This program is free software: you can redistribute it and/or modify it under
// the terms of the GNU General Public License as published by the Free Software
// Foundation, either version 3 of the License, or (at your option) any later
// version.
//
// This program is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
// FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License along with
// this program. If not, see <http://www.gnu.org/licenses/>.
//

import { default as axios } from 'axios';
import { throttle } from 'lodash';

import config from 'app/config';

import * as app from 'app/util/applib';

const log = app.createLog('yell');

export enum Severity {
    Warning,
    Critical,
}

const trashIt = [
    'Async._drainQueue',
    'Async.drainQueue',
    'processImmediate',
    'Promise._settlePromise',
    'runCallback',
    'tryCatcher',
    'tryOnImmediate',
];

const pathRegex = new RegExp(`${app.rootPath}/?`, 'g');
const trashRegex = new RegExp(`^.*(?:${trashIt.join('|')}).*$`, 'gm');
const crlfRegex = /[\r\n]+/gm;

export function yell (
    err : Error,
    severity : Severity = Severity.Warning
) : void {
    // Make the stack trace prettier by removing clutter
    const stackTr = err.stack
        .replace(pathRegex, '')
        .replace(trashRegex, '')
        .replace(crlfRegex, '\n')
        .trim();

    // Complain on our local console, because, why not?
    log(stackTr);

    // If the Slack integration isn't configured, we're done here
    if (config.get('slack.webhook')) {
        slackThrottled(severity, stackTr);
    }
}

export function notify(text : string) : void {
    const slackPayload : any = {
        username: config.get('slack.botname'),
        icon_emoji: ':robot_face:',
        text,
    };

    if (config.get('slack.channel')) {
        slackPayload.channel = config.get('slack.channel');
    }

    axios.post(config.get('slack.webhook'), slackPayload)
    .then(() => null)
    .catch(() => null);
}

// Slack has a hard limit on messages that will be accepted from one sender.
// Bots that break this limit will be silenced until they are manually enabled
// again. So before risking to run into this limit, throttle the sending of
// Slack messages to one every two seconds. Should there really be this much
// traffic in the notification channel, someone better take a closer look anyway
// so it doesn't matter that we're probably discarding some of the exceptions.
// They can be found in the application logs anyway.
const slackThrottled = throttle(slackIt, 2000, {
    leading: true,
    trailing: false,
});

function slackIt(severity : Severity, stackTr : string) : void {
    const slackPayload : any = {
        username: config.get('slack.botname'),
        icon_emoji: getEmoji(severity),
        text: stackTr,
    };

    if (config.get('slack.channel')) {
        slackPayload.channel = config.get('slack.channel');
    }

    axios.post(config.get('slack.webhook'), slackPayload)
    .then(() => null)
    .catch(() => null);
}

const getEmoji = (severity : Severity) : string => {
    switch (severity) {
        case Severity.Warning:
            return ':worried:';
        case Severity.Critical:
            return ':rage:';
    }
    return ':no_mouth:';
};