refactor(docs-infra): switch `test-pwa-score.js` to async/await (#29953)

PR Close #29953

aio/scripts/test-pwa-score.js

@@ -2,7 +2,9 @@
 
 /**
  * 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.
@@ -32,7 +34,7 @@ if (process.env.CI) {
 _main(process.argv.slice(2));
 
 // Functions - Definitions
-function _main(args) {
+async function _main(args) {
   const {url, minScore, logFile} = parseInput(args);
   const isOnHttp = /^http:/.test(url);
 
@@ -44,10 +46,13 @@ function _main(args) {
 
   logger.setLevel(LIGHTHOUSE_FLAGS.logLevel);
 
-  launchChromeAndRunLighthouse(url, LIGHTHOUSE_FLAGS, config).
-    then(results => processResults(results, logFile)).
-    then(score => evaluateScore(minScore, score)).
-    catch(onError);
+  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) {
@@ -60,13 +65,15 @@ function evaluateScore(expectedScore, actualScore) {
   }
 }
 
-function launchChromeAndRunLighthouse(url, flags, config) {
-  return chromeLauncher.launch(CHROME_LAUNCH_OPTS).then(chrome => {
+async function launchChromeAndRunLighthouse(url, flags, config) {
+  const chrome = await chromeLauncher.launch(CHROME_LAUNCH_OPTS);
   flags.port = chrome.port;
-    return lighthouse(url, flags, config).
-      then(results => chrome.kill().then(() => results)).
-      catch(err => chrome.kill().then(() => { throw err; }, () => { throw err; }));
-  });
+
+  try {
+    return await lighthouse(url, flags, config);
+  } finally {
+    await chrome.kill();
+  }
 }
 
 function onError(err) {
@@ -88,24 +95,22 @@ function parseInput(args) {
   return {url, minScore, logFile};
 }
 
-function processResults(results, logFile) {
+async function processResults(results, logFile) {
+  const lhVersion = results.lhr.lighthouseVersion;
   const categories = results.lhr.categories;
   const report = results.report;
 
-  return Promise.resolve().
-    then(() => {
   if (logFile) {
-        console.log(`Saving results in '${logFile}'...`);
+    console.log(`\nSaving results in '${logFile}'...`);
     console.log(`(LightHouse viewer: ${VIEWER_URL})`);
 
-        return printer.write(report, printer.OutputMode.json, logFile);
+    await printer.write(report, printer.OutputMode.json, logFile);
   }
-    }).
-    then(() => {
+
   const categoryData = Object.keys(categories).map(name => categories[name]);
   const maxTitleLen = Math.max(...categoryData.map(({title}) => title.length));
 
-      console.log('\nLighthouse version:', results.lhr.lighthouseVersion);
+  console.log(`\nLighthouse version: ${lhVersion}`);
 
   console.log('\nAudit scores:');
   categoryData.forEach(({title, score}) => {
@@ -113,8 +118,8 @@ function processResults(results, logFile) {
     const paddedScore = (score * 100).toFixed(0).padStart(3);
     console.log(`  - ${paddedTitle} ${paddedScore} / 100`);
   });
-    }).
-    then(() => categories.pwa.score * 100);
+
+  return categories.pwa.score * 100;
 }
 
 function skipHttpsAudits(config) {