index.js

/*
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at https://mozilla.org/MPL/2.0/.
 */
const addon = require('./build/Release/addon.node');
module.exports = function (callback, options) {
    const {interval, threshold} = options;
    if (typeof callback !== 'function') {
        throw new TypeError('callback must be a function');
    }
    if (typeof interval !== 'number' || interval <= 0 || interval > Number.MAX_SAFE_INTEGER) {
        throw new Error("invalid value for interval");
    }
    if (typeof threshold !== 'number' || threshold <= 0 || threshold > Number.MAX_SAFE_INTEGER) {
        throw new Error("invalid value for threshold");
    }
    if (!addon.startWatchdog(callback, interval, threshold)) {
        throw new Error("attempted to start addon twice");
    }
    setInterval(addon.heartbeat, interval).unref();
};