Unable to run in parallel with Protractor 6 and shardTestFiles: true

[ben-yocum]

Bug report

• Node Version: 10.15.3
• Protractor Version: 6.0.0
• Angular Version: 6.1.8
• Browser(s): Chrome 74
• Operating System and Version Windows 10

Configuration file:

const path = process.cwd();
module.exports = {
	seleniumAddress: 'http://localhost:4444/wd/hub',
	framework: 'custom',
	frameworkPath: require.resolve('protractor-cucumber-framework'),

	specs: [ `${path}/features/**/*.feature` ],

	capabilities: {
		browserName: 'chrome',
		'chromeOptions': {
			'args': ['--headless', '--disable-gpu', '--disable-extensions', '--no-sandbox']
		},
		shardTestFiles: true,
		maxInstances: 2
	},
};

This configuration will fail to execute two tests in parallel. I have tracked down the bug in the Protractor source code.

The problem is in launcher.ts.

protractor/lib/launcher.ts

Lines 247 to 251 in 4f74a4e

	const maxConcurrentTasks = scheduler.maxConcurrentTasks();
	for (let i = 0; i < maxConcurrentTasks; ++i) {
	await createNextTaskRunner();
	}
	logger.info('Running ' + scheduler.countActiveTasks() + ' instances of WebDriver');

The await causes the library to wait for each task to complete before spinning up a new one. This prevents more than a single test from being executed in parallel. I found that this fixed the issue:

  const maxConcurrentTasks = scheduler.maxConcurrentTasks();
  const taskArray = [];
  for (let i = 0; i < maxConcurrentTasks; ++i) {
    taskArray.push(createNextTaskRunner());
  }
  await Promise.all(taskArray);
  logger.info('Running ' + scheduler.countActiveTasks() + ' instances of WebDriver');

I do not believe this is an acceptable production solution, but I am not certain how to properly fix the bug. Let me know if you need more information or a more-complete minimal test case.

[vsravuri]

Could be similar to #5145

[vsravuri]

Both multiCapabilities & shardTestFiles doesn't work in Protractor 6.0.0

[ben-yocum]

Yep, looks like the same problem. Do you think I should close this issue as a duplicate?

[vsravuri]

I added follow up note on #5145

[cnishina]

Duplicate #5145

Closing issue.