cdn-cache-check/utils.js

Makes HTTP requests to URLs and parses response headers to determine caching behaviour

const debug = require('debug')('cdn-cache-check-utils');
debug('Entry: [%s]', __filename);


function formatBytes(bytes, decimals = 2) {
    try {
        if (bytes === 0) {
            return ('0 Bytes');
        } else {
            const k = 1024;
            const dm = decimals < 0 ? 0 : decimals;
            const sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'];

            const i = Math.floor(Math.log(bytes) / Math.log(k));

            return `${parseFloat((bytes / Math.pow(k, i)).toFixed(dm))} ${sizes[i]}`;
        }
    } catch (error) {
        debug('formatBytes() caught an exception: %O', error);
        return (`${bytes} Bytes`);
    }
}

function secondsToHms(seconds) {
    if (seconds) {
        try {
            seconds = Number(seconds);

            let h = Math.floor(seconds / 3600);
            let m = Math.floor(seconds % 3600 / 60);
            let s = Math.floor(seconds % 3600 % 60);

            return `${(`0${h}`).slice(-2)} hours, ${(`0${m}`).slice(-2)} minutes, ${(`0${s}`).slice(-2)} seconds`;
        } catch (error) {
            debug('secondsToHms() caught an exception: %O', error);
            // an unexpected error occurred; return the original value
            return (`${seconds} seconds`);
        }
    } else {
        return ('<invalid>');
    }
}

function millisecondsToHms(milliseconds) {
    if (milliseconds) {
        try {
            let seconds = Number(milliseconds / 1000);

            let h = Math.floor(seconds / 3600);
            let m = Math.floor(seconds % 3600 / 60);
            let s = Math.floor(seconds % 3600 % 60);

            let returnString = '';

            if (h > 0) {
                returnString = `${(`0${h}`).slice(-2)} hours, `;
            }

            if (m > 0) {
                returnString = `${returnString}${(`0${m}`).slice(-2)} minutes, `;
            }

            if (s > 0) {
                if (s === 1) {
                    returnString = `${returnString}${(`0${s}`).slice(-2)} second`;
                } else {
                    returnString = `${returnString}${(`0${s}`).slice(-2)} seconds`;
                }
            }

            return returnString;
        } catch (error) {
            debug('millisecondsToHms() caught an exception: %O', error);
            // an unexpected error occurred; return the original value
            return (`${milliseconds} milliseconds`);
        }
    } else {
        return ('<invalid>');
    }
}

function getColourLevelDesc() {
    const colourLevel = ['Colours Disabled', '16 Colours (Basic)', '256 Colours', '16 Million Colours (True Colour)'];

    // Use chalk to detect colour level support
    const chalk = require('chalk');
    let level = chalk.supportsColor.level;

    if (level === null) {
        level = 0;
    }

    return (colourLevel[level]);
}

function getHeadersCollections(settings) {
    debug('getHeadersCollections()');
    try {
        let collections = [];
        for (let i = 0; i < settings.headersCollections.length; i++) {
            collections.push(Object.keys(settings.headersCollections[i]).toString());
        }

        return collections;

    } catch (error) {
        debug('Error caught in getHeadersCollections(): %O', error);
        return [];
    }
}

function IsTLD(testString) {
    debug('IsTLD(%s)', testString);
    try {
        // Load array of valid top-level-domains
        let tlds = require('tlds');

        // Query array for supplied string
        if (tlds.indexOf(testString) > -1) {
            // `testString` exists
            return (true);
        } else {
            // `testString` does not exist
            return (false);
        }
    } catch (error) {
        debug('IsTLD() caught an error: %O', error);
        return (false);
    }
}

function generateUniqueFilename(extension) {
    debug('generateUniqueFilename(%s)', extension);
    const defaultExtension = '.csv';
    const os = require('os');
    const path = require('path');

    let prefix = 'ccc-';

    try {
        const uniqueFilename = require('unique-filename');
        const today = new Date();

        // Check if a file extension was provided
        if (extension) {
            // Prepend a dot '.' if there isn't one
            if ((extension.charAt(0) === '.') === false) {
                extension = `.${extension}`
            }
        } else {
            extension = defaultExtension;
        }

        // Incorporate today's date into the prefix
        prefix = prefix + (today.getFullYear()).toString() + (today.getMonth() + 1).toString() + (today.getDay() + 1).toString();

        // Generate full filename with path
        let filename = uniqueFilename(os.tmpdir(), prefix) + extension;
        debug('Generated the unique filename: %s', filename);
        // return the resulting filename
        return (filename);

    } catch (error) {
        debug('generateUniqueFilename() caught an error: %O', error);
        // We need to return something, so generate a random 8 char string and apply prefix and extension
        let filename = os.tmpdir() + path.sep + prefix + Math.random().toString().substring(2, 10) + defaultExtension;
        return (filename);
    }
}

function getAppPath() {
    let path = require('path');
    let AppPath = path.resolve(__dirname);
    return (AppPath);
}

module.exports = { getAppPath, generateUniqueFilename, IsTLD, getHeadersCollections, getColourLevelDesc, millisecondsToHms, secondsToHms, formatBytes };