If a browsertime marks a test as a failure, exit with error code (#4047)

bin/sitespeed.js

@@ -148,6 +148,14 @@ async function start() {
         execSync('xdg-open ' + result.localPath + '/index.html');
       }
 
+      // If one of the URLs is marked as a failure in Browsertime
+      // then set the exit code
+      for (let bt of result.browsertime) {
+        if (bt.markedAsFailure === 1) {
+          process.exitCode = 1;
+        }
+      }
+
       if (
         parsed.options.budget &&
         Object.keys(result.budgetResult.failing).length > 0

lib/plugins/browsertime/index.js

@@ -364,6 +364,8 @@ export default class BrowsertimePlugin extends SitespeedioPlugin {
                 run.extras = result[resultIndex].extras[runIndex];
               }
 
+              run.markedAsFailure = result[resultIndex].markedAsFailure;
+
               if (
                 result[resultIndex].cdp &&
                 result[resultIndex].cdp.performance