Testing with
Playwright

Chris Ayers

Chris Ayers

Principal Software Engineer
Azure EngOps AzRel
Microsoft

BlueSky: @chris-ayers.com
LinkedIn: - chris-l-ayers
Blog: https://chris-ayers.com/
GitHub: Codebytes
Mastodon: @Chrisayers@hachyderm.io
Twitter: @Chris_L_Ayers

Agenda

  • What is Testing?
  • What is Playwright?
  • Benefits of Using Playwright
  • Creating End-to-End Tests with Playwright
  • Integrating with Continuous Integration

What is Testing?

Testing is the systematic process of verifying and validating that a software application or system meets specified requirements and functions correctly.

Types of Testing

  • Unit Testing
  • Integration Testing
  • System Testing
  • Acceptance Testing
  • End-to-End (E2E) Testing
  • Accessibility Testing
  • Visual Testing
  • Component Testing

UI Testing Best Practices

  • Test user-visible behavior
  • Make tests as isolated as possible
  • Avoid testing third-party dependencies
  • If you test with a database, control the data

Testing Challenges

  • Testing is hard
  • Testing takes time to learn
  • Testing time to build
  • Testing culture
  • Tests are slow
  • Tests are brittle
  • Tests are flaky

Lets try to make testing easier... with

center

What is Playwright?

  • Open Source released by Microsoft in 2020

  • A Modern web test framework
  • Works with Headless or Headed Browsers
    • Chromium - Chrome/Edge
    • Firefox
    • WebKit

Language Support

  • Bindings for:
    • Python
    • Javascript/Typescript
    • Java
    • .NET

Playwright Architecture

  • Language Bindings
  • Single Automation Protocol
  • Abstracts debugging protocols

Benefits of Using Playwright

Reliable & Stable

  • Automatically waits for UI to be ready.
  • Handles dynamic content, animations, and AJAX requests gracefully.
  • Minimizes flaky tests.
  • Isolation with Browser Contexts

Browser Contexts

Browser Contexts provide a way to operate multiple independent browser sessions.

If a page opens another page, e.g. with a window.open call, the popup will belong to the parent page's browser context.

Mobile Emulation

  • Easily emulate various mobile devices.
    • Mobile Chrome
    • Mobile Safari
    • Emulate Viewports and Scale
  • Test responsiveness and mobile-specific features.
  • Ability to emulate location via geolocation

Advanced Interactions

  • Network request interception.
  • Create custom scenarios (e.g., offline mode, slow network).
  • API Mocking
    • HAR file support

Native Context Automation

  • Automate beyond the browser:
    • Upload & download files
    • Work with iframes and shadow DOM
// Get frame using the frame's name attribute
const frame = page.frame('frame-login');

// Get frame using frame's URL
const frame = page.frame({ url: /.*domain.*/ });

// Interact with the frame
await frame.fill('#username-input', 'John');

Fast Execution

  • Tests are executed swiftly, reducing waiting time.
  • Parallel test execution.
  • Optimal performance due to its architecture.
  • Isolation with Browser Contexts

Auto-Waiting

For example, for page.click(), Playwright will ensure that:

  • element is Attached to the DOM
  • element is Visible
  • element is Stable, as in not animating or completed animation
  • element Receives Events, as in not obscured by other elements
  • element is Enabled

See a full list of actions at: https://playwright.dev/docs/actionability

Locators

Method Description
page.getByRole() Locate by explicit and implicit accessibility attributes.
page.getByText() Locate by text content.
page.getByLabel() Locate a form control by associated label's text.
page.getByPlaceholder() Locate an input by placeholder.
page.getByAltText() Locate an element, usually image, by its text alternative.
page.getByTitle() Locate an element by its title attribute.
page.getByTestId() Locate an element based on its data-testid attribute.

Web-First Assertions
expect(locator) expect(locator/page/response)
expect(locator).toBeAttached() expect(locator).toHaveClass()
expect(locator).toBeChecked() expect(locator).toHaveCount()
expect(locator).toBeDisabled() expect(locator).toHaveCSS()
expect(locator).toBeEditable() expect(locator).toHaveId()
expect(locator).toBeEmpty() expect(locator).toHaveJSProperty()
expect(locator).toBeEnabled() expect(locator).toHaveScreenshot()

Web-First Assertions (continued)
expect(locator) expect(locator/page/response)
expect(locator).toBeFocused() expect(locator).toHaveText()
expect(locator).toBeHidden() expect(locator).toHaveValue()
expect(locator).toBeInViewport() expect(locator).toHaveValues()
expect(locator).toBeVisible() expect(page).toHaveTitle()
expect(locator).toContainText() expect(page).toHaveURL()
expect(locator).toHaveAttribute() expect(response).toBeOK()

Visual evidence

  • Screenshot support
  • Video Recording
Still from the Playwright test recording

Rich Tooling Ecosystem

  • VS Code Extension
  • Integrations with popular CI/CD services.
  • Compatible with multiple assertion libraries.

Playwright Extension

Integration with IDE Testing

Codegen

Playwright Test Generator is a GUI tool that helps you record Playwright tests

UI Mode

Run tests and visually see how it runs

Playwright Best Practices

  • Use locators
    • Use chaining and filtering
    • Prefer user-facing attributes to XPath or CSS selectors
  • Generate locators
    • Use codegen to generate locators
    • Use the VS Code extension to generate locators
  • Use web first assertions
    • Don't use manual assertions

Playwright Best Practices

  • Configure debugging
    • Local debugging
    • Debugging on CI
  • Use Playwright's Tooling
  • Test across all browsers
  • Keep your Playwright dependency up to date
  • Run tests on CI
  • Lint your tests
    • Use parallelism and sharding

DEMOS

Microsoft Playwright Testing

Join the waitlist for Microsoft Playwright Testing private preview
• New Azure service for running Playwright tests.
• Cloud enabled to run Playwright tests at scale.
• High parallelization across operating system-browser combinations.
• Speed up delivery of features without sacrificing quality.

Private Preview

To learn more about Microsoft Playwright Testing, refer to:
https://aka.ms/mpt/private-preview-blog.

Questions?

Contact

BlueSky: @chris-ayers.com
LinkedIn: - chris-l-ayers
Blog: https://chris-ayers.com/
GitHub: Codebytes
Mastodon: @Chrisayers@hachyderm.io
Twitter: @Chris_L_Ayers

## Purpose - **Detect Errors** - **Enhance Quality** - **Reduce Costs** - **Increase User Satisfaction**