Crash mocha on uncaught errors in the e2e runner

Bug: none
Change-Id: Ia2720d6a14c189475026fe145a2693dd4817c63b
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/6081454
Reviewed-by: Simon Zünd <[email protected]>
Commit-Queue: Alex Rudenko <[email protected]>

Author: OrKoN

test/e2e/mocharc.ts

@@ -7,6 +7,9 @@ import * as path from 'path';
 import {loadTests, TestConfig} from '../conductor/test_config.js';
 
 module.exports = {
+  // This should make mocha crash on uncaught errors.
+  // See https://github.com/mochajs/mocha/blob/master/docs/index.md#--allow-uncaught.
+  allowUncaught : true,
   require : [path.join(path.dirname(__dirname), 'conductor', 'mocha_hooks.js'), 'source-map-support/register'],
   spec : loadTests(__dirname),
   timeout : TestConfig.debug ? 0 : 10_000,