Parse a webpack json output to compute size of our files vs. depedendencies

analysis.js

const buildStats = require('./build.json');

function getSize(modules) {
    return modules.reduce((acc, val) => acc + val.size, 0);
}

const tpl = (type, modules) => `${type} files
--------
no. of modules: ${modules.length}
total size: ${Math.round(getSize(modules) / 1000)} KB`

function parseOptions() {
    const options = { chunk: -1, listChunks: false };
    var args = process.argv.slice(2);

    for (var i = 0; i < args.length; i++) {
        if (args[i] === '--chunk' || args[i] === '-c') {
            options.chunk = args[++i];
        } else if (args[i] === '--list' || args[i] === '-l') {
            options.listChunks = true;
        }
    }
    return options;
}

function printChunkStats(chunk) {
    const allModules = chunk.modules;
    const myModules = chunk.modules.filter(m => m.name.startsWith('./src'));

    console.log(chunk.names[0] + '\n========\n');
    console.log(tpl('my', allModules));
    console.log('');
    console.log(tpl('all', myModules));

    const diff = (getSize(myModules) / getSize(allModules)) * 100;
    console.log(`\nmy code: ${Math.round(diff)}%\n`);
}

function init(options) {
    if (options.listChunks) {
        const chunksNames = buildStats.chunks.map(c => c.names[0]);
        console.log(`chunks: ${JSON.stringify(chunksNames)}\n`);
        return;
    }
    if (options.chunk === -1)
        buildStats.chunks.forEach((val) => printChunkStats(val));
    else if (options.chunk >= 0 && options.chunk <= buildStats.chunks.length)
        printChunkStats(buildStats.chunks[options.chunk]);
}

const options = parseOptions();
init(options);