Teardown of Multiple Threaded Tests with Selenium

Question

I'm trying to run multiple test cases with Nunit in C# in which every test needs its own Selenium Chrome Driver.

Before it was threaded, I handled the chrome driver with [Setup] and [Teardown] like so:

[TestFixture]
[SingleThreaded]
 public class MyThreadedTest
{
    private IWebDriver _driver;

    [SetUp]
    public void Setup()
    {
        _driver = new ChromeDriver();
        _driver.Manage().Timeouts().ImplicitWait = TimeSpan.FromSeconds(10);
    }

    [TearDown]
    public void Teardown()
    {
        _driver?.Quit();
    }
...

Now, however, I'm using [Parallelizable(ParallelScope.All)] instead of [SingleThreaded].

This means that all of my test cases that happen below that will all attempt to use the same Chrome Driver, instead of spawning a new one for each session.

A solution to this problem would be to do the setup and tear down in the actual test case, but then I don't get the nice tear down function that I've come to love with Nunit, because the driver will wind up being out of scope.

So my question is this: Is there a way to handle threaded setup and tear down in a more graceful way? I'm looking for some way to handle threaded setup and teardown; similar to what this answer touches on.

Answer 1

You can try using the ThreadLocal Class, so each running thread would be assigned it's own webdriver instance.

See pseudocode to get the idea:

private static readonly ThreadLocal<IWebDriver> WebDrivers = new ThreadLocal<IWebDriver>();

public static IWebDriver Instance
{
    get
    {
        if (WebDrivers.Value == null)
        {
            Log.Warn("Please call method 'Start' before can get Driver");
        }

        return WebDrivers.Value;
    }

    set => WebDrivers.Value = value;
}

public static void Start()
{
    WebDrivers.Value = new ChromeDriver();
}