utilities.js

import Table from 'easy-table';
import fs from 'fs';
import http from 'http';
import url from 'url';
import path from 'path';
import gzipSize from 'gzip-size';

export const toKebabCase = n =>
    n.replace(/Case$/, '').replace(/([a-z])([A-Z])/g, (match, c1, c2) => `${c1}-${c2.toLowerCase()}`);

export const pad = (n) => {
    const titleLength = 30;
    const p = '====================';
    const title = `${p} ${n} ${p}`;
    const offset = (title.length - titleLength) / 2;
    return title.substr(offset, titleLength);
};

export const OUTPUT = './output/';

export const createOutputDir = (testName) => {
    const outputDir = OUTPUT + testName;
    if (!fs.existsSync(OUTPUT)) {
        fs.mkdirSync(OUTPUT);
    }
    if (!fs.existsSync(outputDir)) {
        fs.mkdirSync(outputDir);
    }
    return outputDir;
};

export const toClasses = (css) => {
    const newCss = {};
    Object.keys(css).forEach((className) => {
        newCss[`.${className}`] = css[className];
    });
    return newCss;
};

export const getSizeResults = testCases => (
    Object.keys(testCases).map((caseName) => {
        const result = testCases[caseName].result;
        return {
            caseName,
            size: result.length,
            gzippedSize: gzipSize.sync(result),
        };
    })
);

export const sizeTable = (sizeResults) => {
    const t = new Table();
    sizeResults.forEach((sr) => {
        t.cell('name', sr.caseName);
        t.cell('size', `${sr.size.toLocaleString()} B`, Table.padLeft);
        t.cell('gzipped size', `(${sr.gzippedSize.toLocaleString()} B gzipped)`, Table.padLeft);
        t.newRow();
    });
    return t;
};

export const getSmallest = (_sizeResults, size, { threshold = 0.05 } = {}) => {
    const sizeResults = Array.from(_sizeResults); // clone so sort won't mutate original
    sizeResults.sort((a, b) => a[size] - b[size]);

    const smallest = sizeResults[0];
    const smallestThreshold = smallest[size] * (1 + threshold);

    return sizeResults.filter(sr => sr[size] <= smallestThreshold);
};

export const indent = (lines, { repeat = 2, character = ' ' } = {}) => (
    lines
        .split('\n')
        .map(line => character.repeat(repeat) + line)
        .join('\n')
);

export const httpServer = {
    start(dir, port) {
        this.server = http.createServer((req, res) => {
            var filename = path.join(dir, '..', url.parse(req.url).pathname);
            fs.stat(filename, (err, stat) => {
                if (!err && stat.isFile()) {
                    res.writeHead(200, 'text/html');
                    fs.createReadStream(filename).pipe(res);
                } else {
                    res.end();
                }
            });
        });
        this.server.listen(port);
    },
    stop() {
        this.server.close();
    }
}