angular-cn/aio/scripts/test-pwa-score.js

136 lines
4.0 KiB
JavaScript

#!/bin/env node
/**
* Usage:
* ```sh
* node scripts/test-pwa-score <url> <min-score> [<log-file>]
* ```
*
* Fails if the score is below `<min-score>`.
* If `<log-file>` is defined, the full results will be logged there.
*
* (Skips HTTPS-related audits, when run for HTTP URL.)
*/
// Imports
const chromeLauncher = require('chrome-launcher');
const lighthouse = require('lighthouse');
const printer = require('lighthouse/lighthouse-cli/printer');
const logger = require('lighthouse-logger');
// Constants
const CHROME_LAUNCH_OPTS = {};
const LIGHTHOUSE_FLAGS = {logLevel: 'info'};
const SKIPPED_HTTPS_AUDITS = ['redirects-http'];
const VIEWER_URL = 'https://googlechrome.github.io/lighthouse/viewer/';
const WAIT_FOR_SW_DELAY = 5000;
// Be less verbose on CI.
if (process.env.CI) {
LIGHTHOUSE_FLAGS.logLevel = 'error';
}
// Run
_main(process.argv.slice(2));
// Functions - Definitions
async function _main(args) {
const {url, minScore, logFile} = parseInput(args);
const isOnHttp = /^http:/.test(url);
const config = {
extends: 'lighthouse:default',
// Since the Angular ServiceWorker waits for the app to stabilize before registering,
// wait a few seconds after load to allow Lighthouse to reliably detect it.
passes: [{passName: 'defaultPass', pauseAfterLoadMs: WAIT_FOR_SW_DELAY}],
}
console.log(`Running PWA audit for '${url}'...`);
// If testing on HTTP, skip HTTPS-specific tests.
// (Note: Browsers special-case localhost and run ServiceWorker even on HTTP.)
if (isOnHttp) skipHttpsAudits(config);
logger.setLevel(LIGHTHOUSE_FLAGS.logLevel);
try {
const results = await launchChromeAndRunLighthouse(url, LIGHTHOUSE_FLAGS, config);
const score = await processResults(results, logFile);
evaluateScore(minScore, score);
} catch (err) {
onError(err);
}
}
function evaluateScore(expectedScore, actualScore) {
console.log('\nLighthouse PWA score:');
console.log(` - Expected: ${expectedScore.toFixed(0).padStart(3)} / 100 (or higher)`);
console.log(` - Actual: ${actualScore.toFixed(0).padStart(3)} / 100\n`);
if (isNaN(actualScore) || (actualScore < expectedScore)) {
throw new Error(`PWA score is too low. (${actualScore} < ${expectedScore})`);
}
}
async function launchChromeAndRunLighthouse(url, flags, config) {
const chrome = await chromeLauncher.launch(CHROME_LAUNCH_OPTS);
flags.port = chrome.port;
try {
return await lighthouse(url, flags, config);
} finally {
await chrome.kill();
}
}
function onError(err) {
console.error(err);
process.exit(1);
}
function parseInput(args) {
const url = args[0];
const minScore = Number(args[1]);
const logFile = args[2];
if (!url) {
onError('Invalid arguments: <URL> not specified.');
} else if (isNaN(minScore)) {
onError('Invalid arguments: <MIN_SCORE> not specified or not a number.');
}
return {url, minScore, logFile};
}
async function processResults(results, logFile) {
const lhVersion = results.lhr.lighthouseVersion;
const categories = results.lhr.categories;
const report = results.report;
if (logFile) {
console.log(`\nSaving results in '${logFile}'...`);
console.log(`(LightHouse viewer: ${VIEWER_URL})`);
await printer.write(report, printer.OutputMode.json, logFile);
}
const categoryData = Object.keys(categories).map(name => categories[name]);
const maxTitleLen = Math.max(...categoryData.map(({title}) => title.length));
console.log(`\nLighthouse version: ${lhVersion}`);
console.log('\nAudit scores:');
categoryData.forEach(({title, score}) => {
const paddedTitle = `${title}:`.padEnd(maxTitleLen + 1);
const paddedScore = (score * 100).toFixed(0).padStart(3);
console.log(` - ${paddedTitle} ${paddedScore} / 100`);
});
return categories.pwa.score * 100;
}
function skipHttpsAudits(config) {
console.info(`Skipping HTTPS-related audits (${SKIPPED_HTTPS_AUDITS.join(', ')})...`);
const settings = config.settings || (config.settings = {});
settings.skipAudits = SKIPPED_HTTPS_AUDITS;
}