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Writing Tests

Playwright assertions are created specifically for the dynamic web. Checks are automatically retried until the necessary conditions are met. Playwright comes with auto-wait built in meaning it waits for elements to be actionable prior to performing actions. Playwright provides the Expect function to write assertions.

Take a look at the example test below to see how to write a test using using locators and web first assertions.

using System.Text.RegularExpressions;
using Microsoft.Playwright.NUnit;

namespace PlaywrightTests;

[Parallelizable(ParallelScope.Self)]
[TestFixture]
public class Tests : PageTest
{
[Test]
public async Task HomepageHasPlaywrightInTitleAndGetStartedLinkLinkingtoTheIntroPage()
{
await Page.GotoAsync("https://playwright.dev");

// Expect a title "to contain" a substring.
await Expect(Page).ToHaveTitleAsync(new Regex("Playwright"));

// create a locator
var getStarted = Page.GetByRole(AriaRole.Link, new() { NameString = "Get started" });

// Expect an attribute "to be strictly equal" to the value.
await Expect(getStarted).ToHaveAttributeAsync("href", "/docs/intro");

// Click the get started link.
await getStarted.ClickAsync();

// Expects the URL to contain intro.
await Expect(Page).ToHaveURLAsync(new Regex(".*intro"));
}
}

Assertions

Playwright provides an async function called Expect to assert and wait until the expected condition is met.

await Expect(Page).ToHaveTitleAsync(new Regex("Playwright"));

Locators

Locators are the central piece of Playwright's auto-waiting and retry-ability. Locators represent a way to find element(s) on the page at any moment and are used to perform actions on elements such as .ClickAsync .FillAsync etc.

var getStarted = Page.GetByRole(AriaRole.Link, new() { NameString = "Get started" });

await Expect(getStarted).ToHaveAttributeAsync("href", "/docs/installation");
await getStarted.ClickAsync();

Test Isolation

The Playwright NUnit and MSTest test framework base classes will isolate each test from each other by providing a separate Page instance. Pages are isolated between tests due to the Browser Context, which is equivalent to a brand new browser profile, where every test gets a fresh environment, even when multiple tests run in a single Browser.

using System.Threading.Tasks;
using Microsoft.Playwright.NUnit;
using NUnit.Framework;

namespace PlaywrightTests;

[Parallelizable(ParallelScope.Self)]
[TestFixture]
public class Tests : PageTest
{
[Test]
public async Task BasicTest()
{
await Page.GotoAsync("https://playwright.dev");
}
}

Using Test Hooks

You can use SetUp/TearDown in NUnit or TestInitialize/TestCleanup in MSTest to prepare and clean up your test environment:

using System.Threading.Tasks;
using Microsoft.Playwright.NUnit;
using NUnit.Framework;

namespace PlaywrightTests;

[Parallelizable(ParallelScope.Self)]
[TestFixture]
public class Tests : PageTest
{
[Test]
public async Task MainNavigation()
{
// Assertions use the expect API.
await Expect(Page).ToHaveURLAsync("https://playwright.dev/");
}

[SetUp]
public async Task SetUp()
{
await Page.GotoAsync("https://playwright.dev");
}
}

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