Count source code lines for npm packages from GitHub org

'use strict';

const fs = require('fs');
const path = require('path');
const util = require('util');
const childProcess = require('child_process');
const gh = require('gh-got');
const mkdirtemp = require('mkdirtemp');

const exec = util.promisify(childProcess.exec);
const execFile = util.promisify(childProcess.execFile);

// Tip: Add an access token in the GITHUB_TOKEN environment variable to increase rate limits.
const api = gh.extend();

(async () => {
    console.log('Fetching list of repositories...')
    const repos = await api.paginate.all('users/hapijs/repos');

    const tempDir = await mkdirtemp();
    console.log('Downloading packages to temp directory:', tempDir);
    process.chdir(tempDir);

    const lineCounts = await Promise.all(repos.map(async (repo) => {
        const pkgUrl = new URL(repo.contents_url.replace(/\/\{\+path\}$/, '/package.json'));
        try {
            await api.head(pkgUrl.pathname + pkgUrl.search + pkgUrl.hash, { prefixUrl : pkgUrl.origin });
        }
        catch (error) {
            if (error.response?.statusCode === 404) {
                return 0;
            }
            throw error;
        }

        const pack = await execFile('npm', ['pack', repo.full_name], { cwd : tempDir });
        const archiveName = pack.stdout.trim();
        const archivePath = path.join(tempDir, archiveName);
        const pkgId = path.parse(archiveName).name;
        const unpackDir = path.join(tempDir, pkgId);
        await fs.promises.mkdir(unpackDir);
        await execFile('tar', ['-xzf', archivePath, '--strip-components=1'], { cwd : unpackDir });
        const wc = await exec('wc -l **.{j,t}s', { cwd : unpackDir, shell : 'fish' });
        const numLines = Number.parseInt(wc.stdout.trimRight().split(/\r?\n/).slice(-1));
        return numLines;
    }));

    const lineTotal = lineCounts.reduce((result, lineCount) => {
        return result + lineCount;
    }, 0);

    console.log('Number of repos:', repos.length);
    console.log('Total lines:', lineTotal);
})();