version-checker.js

'use strict';

const { getOptionValue } = require('internal/options');
const { get } = require('https');
const { gt: semverGt, clean: semverClean, major: semverMajor } = require('semver');

function compareVersions(current, other, security) {
    if (semverGt(other, current)) {
        let message = `New version available! v${current} (current) -> v${other} (new)`;
        if (security)
            message += ' (security release)';

        process.emitWarning(message);
    }
}

// Marked w/ default value just for testing
const checkUpdate = 'same'; /* = getOptionValue('--check-update');*/
if (checkUpdate) {
    const versionsUrl = getOptionValue('--version-checker-url') ?? 'https://nodejs.org/dist/index.json';
    get(versionsUrl, res => {
        const { statusCode, headers } = res;
        if (statusCode !== 200) {
            process.emitWarning(`Version checker failed: received status code ${statusCode}`);
            res.resume();
            return;
        }

        if (headers['content-type'] !== 'application/json') {
            process.emitWarning('Version checker failed: content-type not application/json');
            res.resume();
            return;
        }

        res.setEncoding('utf8');

        let releasesString = '';
        res.on('data', chunk => releasesString += chunk);
        res.on('error', e => process.emitWarning(`Version checker failed: ${e.message}`));
        res.on('end', () => {
            try {
                const releases = JSON.parse(releasesString);
                if (releases.length === 0)
                    return;

                const nodeVersion = '16.0.0'; //semverClean(process.version);
                switch (checkUpdate.toLowerCase()) {
                    case true: // When it's passed w/o value
                    case 'current': {
                        const latestVersion = semverClean(releases[0].version);
                        compareVersions(nodeVersion, latestVersion, releases[0].security);
                        break;
                    }
                    case 'lts': {
                        for (const release of releases) {
                            if (!release.lts)
                                continue;

                            const version = semverClean(release.version);
                            compareVersions(nodeVersion, version, release.security);

                            break;
                        }

                        break;
                    }
                    case 'same': {
                        const nodeMajor = semverMajor(nodeVersion);
                        for (const release of releases) {
                            const version = semverClean(release.version);
                            const releaseMajor = semverMajor(version);
                            if (releaseMajor !== nodeMajor)
                                continue;

                            compareVersions(nodeVersion, version, release.security);

                            break;
                        }

                        break;
                    }
                    case 'off':
                        break;
                    default:
                        process.emitWarning('Version checker failed: invalid value of --check-update. Valid options: current, lts, same, and off.');
                        break;
                }
            } catch (e) {
                process.emitWarning(`Version checker failed: ${e.message}`);
            }
        });
    });
}