format-lighthouse-score.mjs

/* eslint-disable header/header */
/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

// @ts-check

/** @typedef {Record<'performance' | 'accessibility' | 'best-practices' | 'seo' | 'pwa', number>} LighthouseSummary */

/** @type {Record<keyof LighthouseSummary, string>} */
const summaryKeys = {
    performance: 'Performance',
    accessibility: 'Accessibility',
    'best-practices': 'Best Practices',
    seo: 'SEO',
    pwa: 'PWA',
};

/** @param {number} rawScore */
const scoreEntry = (rawScore) => {
    const score = Math.round(rawScore * 100);
    // eslint-disable-next-line no-nested-ternary
    const scoreIcon = score >= 90 ? '🟢' : score >= 50 ? '🟠' : '🔴';
    return `${scoreIcon} ${score}`;
};

/**
 * @param {Object} param0
 * @param {string} param0.url
 * @param {LighthouseSummary} param0.summary
 * @param {string} param0.reportUrl
 */
const createMarkdownTableRow = ({ url, summary, reportUrl }) => [
    `| [${new URL(url).pathname}](${url})`,
    ...Object.keys(summaryKeys).map((k) => scoreEntry(summary[k])),
    `[Report](${reportUrl}) |`,
].join(' | ');

const createMarkdownTableHeader = () => [
    ['| URL', ...Object.values(summaryKeys), 'Report |'].join(' | '),
    ['|---', ...Array(Object.keys(summaryKeys).length).fill('---'), '---|'].join(
        '|',
    ),
];

/**
 * @param {Object} param0
 * @param {Record<string, string>} param0.links
 * @param {{url: string, summary: LighthouseSummary}[]} param0.results
 */
const createLighthouseReport = ({ results, links }) => {
    const tableHeader = createMarkdownTableHeader();
    const tableBody = results.map((result) => {
        const testUrl = Object.keys(links).find((key) => key === result.url);
        const reportPublicUrl = links[testUrl];

        return createMarkdownTableRow({
            url: testUrl,
            summary: result.summary,
            reportUrl: reportPublicUrl,
        });
    });
    const comment = [
        '### ⚡️ Lighthouse report for the deploy preview of this PR',
        '',
        ...tableHeader,
        ...tableBody,
        '',
    ];
    return comment.join('\n');
};

export default createLighthouseReport;