Error message when trying to run ChromeDriver for codeception

I am wanting to use Webdriver in my codeception acceptance tests and am getting errors. I see I have to have the chromedriver running and tried running it from the command window and it seems to run fine using: chromedriver --url-base=/wd/hub. I want to use the RunProcess extension so added this to my acceptance.suite.yml file:

actor: AcceptanceTester
extensions:
    enabled:
        - Codecption\Extensions\RunProcess:
            - chromedriver
modules:
    enabled:
        - WebDriver:
            url: 'http://localhost/flightserve/'
            browser: chrome
        - \Helper\Acceptance
step_decorators: ~

and I get this error message and do not know hoe it needs to be defined. Class Codecption\Extensions\RunProcess is not defined. Autoload it or include into '_bootstrap.php' file of 'tests' directory

Solution

A few issues with your code:

You have some typos with the extension path. It should be Codeception\Extension\RunProcess. So singular 'Extension' and 'Codeception' spelt correctly.
You may still hit issues because the chromedriver hasn't properly started up before the test suite tries to run. You could try introducing a short delay using sleep:

- Codeception\Extension\RunProcess:
    0: chromedriver --url-base=/wd/hub
    sleep: 5