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

121 lines
3.7 KiB
JavaScript

#!/bin/env node
/**
* Usage:
* 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.
*
* (Ignores HTTPS-related audits, when run for HTTP URL.)
*/
// Imports
const lighthouse = require('lighthouse');
const ChromeLauncher = require('lighthouse/lighthouse-cli/chrome-launcher').ChromeLauncher;
const Printer = require('lighthouse/lighthouse-cli/printer');
const config = require('lighthouse/lighthouse-core/config/default.json');
// Constants
const VIEWER_URL = 'https://googlechrome.github.io/lighthouse/viewer/';
// Work-around traceviewer-js bug.
global.atob = str => new Buffer(str, 'base64').toString('binary');
global.btoa = str => new Buffer(str, 'binary').toString('base64');
// Specify the path to Chrome on Travis
if (process.env.TRAVIS) {
process.env.LIGHTHOUSE_CHROMIUM_PATH = process.env.CHROME_BIN;
}
// Run
_main(process.argv.slice(2));
// Functions - Definitions
function _main(args) {
const {url, minScore, logFile} = parseInput(args);
const isOnHttp = /^http:/.test(url);
console.log(`Running PWA audit for '${url}'...`);
if (isOnHttp) {
ignoreHttpsAudits(config.aggregations);
}
launchChromeAndRunLighthouse(url, {}, config).
then(results => processResults(results, logFile)).
then(score => evaluateScore(minScore, score)).
catch(onError);
}
function evaluateScore(expectedScore, actualScore) {
console.log('Lighthouse PWA score:');
console.log(` - Expected: ${expectedScore} / 100 (or higher)`);
console.log(` - Actual: ${actualScore} / 100`);
if (actualScore < expectedScore) {
throw new Error(`PWA score is too low. (${actualScore} < ${expectedScore})`);
}
}
function ignoreHttpsAudits(aggregations) {
const httpsAudits = [
'redirects-http'
];
console.info(`Ignoring HTTPS-related audits (${httpsAudits.join(', ')})...`);
aggregations.forEach(aggregation =>
aggregation.items.forEach(item =>
httpsAudits.map(key => item.audits[key]).forEach(audit =>
// Ugly hack to ignore HTTPS-related audits (i.e. simulate them passing).
// Only meant for use during development.
audit && (audit.expectedValue = !audit.expectedValue))));
}
function launchChromeAndRunLighthouse(url, flags, config) {
const launcher = new ChromeLauncher({autoSelectChrome: true});
return launcher.run().
then(() => lighthouse(url, flags, config)).
// Avoid race condition by adding a delay before killing Chrome.
// (See also https://github.com/paulirish/pwmetrics/issues/63#issuecomment-282721068.)
then(results => new Promise(resolve => setTimeout(() => resolve(results), 1000))).
then(results => launcher.kill().then(() => results)).
catch(err => launcher.kill().then(() => { throw err; }, () => { throw err; }));
}
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};
}
function processResults(results, logFile) {
if (logFile) {
console.log(`Saving results in '${logFile}'...`);
console.log(`(LightHouse viewer: ${VIEWER_URL})`);
results.artifacts = undefined; // Avoid circular dependency errors.
Printer.write(results, 'json', logFile);
}
const scoredAggregations = results.aggregations.filter(a => a.scored);
const total = scoredAggregations.reduce((sum, a) => sum + a.total, 0);
return Math.round((total / scoredAggregations.length) * 100);
}