Storybook test runner

To get your components bulletproofed with the Storybook test runner, here are the detailed steps to integrate and leverage this powerful tool:

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• Install Necessary Packages: First, you’ll need @storybook/test-runner and its peer dependencies. Open your terminal and run:

  
  
  npm install --save-dev @storybook/test-runner jest @testing-library/jest-dom @testing-library/react
  # or
  
  
  yarn add --dev @storybook/test-runner jest @testing-library/jest-dom @testing-library/react
  

• Configure Storybook: Ensure your Storybook setup is standard. The test runner works by interacting with your running Storybook instance, so it needs to be accessible.
• Add a Test Script: In your package.json, add a script to run the test runner. A common setup would be:

  "scripts": {
      "test-storybook": "test-storybook"
  }
  

• Run Storybook in CI/CD: For continuous integration, you’ll typically run Storybook in a “static” build mode and then run the test runner against it.
  • Build Storybook: npm run build-storybook
  • Serve the build: Use a static server like serve or http-server e.g., npx http-server storybook-static --port 9009 --silent.
  • Run tests: npm run test-storybook -- --url http://localhost:9009.
• Utilize Jest and Testing Library: The test runner integrates seamlessly with Jest and Testing Library. Your component stories effectively become your test cases. Ensure your stories are well-written and cover various states and interactions.
• Accessibility Testing: Leverage the built-in a11y checks. This is a significant win, as it automatically checks for common accessibility issues based on your component’s rendered state.
• Visual Regression Optional but Recommended: While the test runner focuses on functionality and accessibility, consider pairing it with visual regression tools like Chromatic or Storybook’s own image snapshotting for a complete testing strategy. This helps catch unintended UI changes.

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The Strategic Advantage of the Storybook Test Runner

The Storybook test runner isn’t just another tool.

It’s a strategic move for front-end development, allowing teams to leverage their existing Storybook stories as comprehensive test suites.

It operates on the principle of running Storybook in a headless browser, executing every story, and performing automated accessibility a11y and interaction tests.

This approach transforms your component documentation into a robust testing ground, ensuring UI components behave as expected and remain accessible.

For teams aiming for high-quality, maintainable UIs, integrating this runner significantly reduces the overhead of writing separate unit or integration tests for visual and interactive aspects, freeing up valuable time for more impactful development work. Desktop automation tools

Bridging the Gap: Documentation as Testing

One of the most compelling aspects of the Storybook test runner is its ability to bridge the gap between documentation and testing.

Traditionally, documenting UI components and writing tests for them were separate, often redundant, efforts.

With the test runner, every story you write to showcase a component’s state or variation automatically becomes a test case.

This paradigm shift means that as you meticulously document your components, you are simultaneously building a thorough test suite. This efficiency gain is substantial.

According to a 2023 survey by Storybook, over 70% of Storybook users reported that their stories already cover most of their UI states, making them prime candidates for automated testing via the runner. Test case specification

This integration not only streamlines workflows but also ensures that your tests are always in sync with your live documentation.

Headless Browser Execution: Under the Hood

The magic of the Storybook test runner lies in its use of a headless browser, typically Playwright, to visit every story in your Storybook instance.

A headless browser is essentially a web browser without a graphical user interface, making it ideal for automated testing environments.

When you execute the test runner, it spins up this headless browser, navigates to each story, and then runs a series of checks.

This includes waiting for the story to render, asserting its basic functionality, and performing automated accessibility checks via tools like Axe. Pyppeteer tutorial

This process mimics how a user would interact with your components, providing a high degree of confidence that your UI is robust and accessible. The performance benefits are also notable.

Testing in a headless environment is significantly faster than launching a full browser, making it suitable for continuous integration CI pipelines.

Seamless Integration with Existing Workflows

Integrating the Storybook test runner into your existing development and CI/CD workflows is remarkably straightforward, often requiring just a few lines of configuration.

Its design philosophy emphasizes minimal friction, allowing teams to adopt it without major overhauls to their current setup.

This ease of integration is crucial for maintaining developer velocity and ensuring that new testing practices don’t become roadblocks. Testng parameters

For example, many teams can add a simple script to their package.json to run the tests, and it slots neatly into pre-commit hooks or CI jobs alongside other quality checks.

Configuring for Development and CI/CD

When it comes to configuration, the Storybook test runner is flexible.

For local development, you might run Storybook in development mode npm run storybook and then execute the test runner against that live instance.

This provides immediate feedback as you develop components.

For CI/CD environments, the process is slightly different but equally streamlined. Automation script

Typically, you’d first build a static version of your Storybook npm run build-storybook, then serve that static build using a lightweight HTTP server like http-server or serve, and finally, run the test runner against the served static Storybook.

This ensures that your CI pipeline is testing the exact production-ready build of your Storybook.

A well-structured package.json often contains scripts like "build-storybook": "build-storybook", "serve-storybook": "http-server storybook-static --port 9009 --silent", "test-ci": "start-server-and-test serve-storybook http://localhost:9009 test-storybook --url http://localhost:9009", enabling robust automated testing in CI.

Pairing with Jest and Testing Library

The Storybook test runner works harmoniously with Jest and Testing Library, leveraging their robust ecosystems for assertions and DOM manipulation.

Under the hood, the test runner essentially creates a Jest environment for each story. Announcing general availability of browserstack app accessibility testing

This means you can use familiar Jest matchers e.g., expectelement.toBeInTheDocument and Testing Library queries e.g., screen.getByText'Hello World' directly within your Storybook play functions.

These play functions allow you to define interactions and assertions that run after a story renders.

For instance, you could simulate a user clicking a button and then assert that a new element appears.

This powerful combination allows you to write highly expressive and effective tests that accurately reflect user behavior, ensuring both visual correctness and interactive functionality.

Core Features and Capabilities

The Storybook test runner comes packed with features designed to make UI testing efficient and comprehensive. Accessibility automation tools

Understanding these features is key to maximizing its utility and ensuring high-quality component libraries.

Automated Accessibility Testing A11y

One of the standout features of the Storybook test runner is its built-in automated accessibility testing.

It integrates with axe-core, the same powerful accessibility engine used by tools like Axe DevTools.

When the test runner visits each story, it automatically runs a series of accessibility checks, identifying common violations such as insufficient color contrast, missing ARIA attributes, or incorrect heading structures.

This means that without writing a single line of explicit accessibility test code, you get invaluable feedback on the accessibility posture of your components. How to use storybook argtypes

According to WebAIM’s 2024 accessibility report, over 96% of home pages still have detectable WCAG 2 failures, highlighting the critical need for automated checks like these.

By catching these issues early in the development cycle, teams can significantly reduce the cost and effort of remediation later on.

Interaction Testing with play Functions

Interaction testing is where the Storybook test runner truly shines.

Using play functions within your stories, you can define asynchronous interactions that simulate user behavior.

These functions execute after a story renders, allowing you to click buttons, type into input fields, hover over elements, and then assert the resulting state of the component. Php debug tool

The play function receives a canvasElement and args object, providing access to the rendered component and its props.

For instance, you could write a play function for a form component that fills in input fields and submits the form, then asserts that a success message is displayed.

This capability ensures that your components not only look correct but also function correctly under various user interactions, providing a high degree of confidence in their robustness.

Snapshot Testing for Visual Regression

While the Storybook test runner primarily focuses on functional and accessibility testing, it can be extended for visual regression testing through snapshot testing.

By default, the test runner doesn’t generate visual snapshots itself, but because it uses Jest under the hood, you can easily integrate Jest’s snapshot testing capabilities. Hotfix vs bugfix

This involves taking a “snapshot” of the rendered HTML structure of your component in a story and saving it.

Subsequent test runs compare the current HTML against the saved snapshot, flagging any differences.

This helps catch unintended changes to the component’s DOM structure.

While not a true pixel-by-pixel visual regression for that, tools like Chromatic or Storybook’s visual testing addons are better suited, DOM snapshotting is a quick and effective way to ensure that your component’s structure remains stable and consistent across changes.

Advanced Use Cases and Best Practices

Moving beyond basic setup, the Storybook test runner offers advanced capabilities and demands certain best practices to unlock its full potential. How to write test cases for login page

Maximizing its value involves thoughtful story design, strategic integration into CI/CD, and understanding how to debug and optimize test runs.

Debugging Failed Tests and Stories

Debugging failed tests with the Storybook test runner is straightforward, thanks to its integration with Jest and the fact that it runs against your actual Storybook.

When a test fails, the runner provides a detailed stack trace, pinpointing the specific story and the assertion that failed.

You can then navigate directly to that story in your running Storybook instance if you have one open to visually inspect the component’s state.

For more complex interactions or timing issues, you can temporarily modify your play function to include console.log statements or even use the await delayms pattern to slow down interactions, giving you time to observe state changes. Understanding element not interactable exception in selenium

Since Playwright is often used under the hood, advanced users can also leverage Playwright’s debugging tools, such as page.pause or page.screenshot, within the play functions to capture the component’s state at specific points during the test run.

Optimizing Performance for Large Storybooks

For large Storybooks with hundreds or thousands of stories, optimizing the performance of the test runner becomes critical to maintain fast feedback loops. One key strategy is to leverage parallelization.

The test runner can run tests concurrently across multiple workers, significantly reducing the total test execution time.

You can configure the number of workers via command-line arguments e.g., test-storybook --workers 4. Another optimization is to implement selective testing.

While running all stories is ideal for CI, during development, you might only want to test stories related to the components you’re actively working on. Simplifying native app testing

The test runner supports filtering stories by ID or title, allowing you to run a subset of tests e.g., test-storybook --stories-url 'http://localhost:6006/?path=/story/components-button--default' or test-storybook --pattern 'button'. Additionally, ensuring your stories are performant and don’t involve heavy computations or network requests during their initial render can drastically speed up test execution.

Integrating with Monorepos and Component Libraries

In monorepo setups or when managing large component libraries, integrating the Storybook test runner requires a coordinated approach.

Typically, each component package within the monorepo would have its own Storybook instance and test runner configuration.

However, for a holistic view, you might have a “root” Storybook that aggregates stories from all packages.

The test runner can be configured to target specific Storybook instances or dynamically discover them. Browserstack newsletter september 2023

For instance, if you have multiple Storybook builds, you could run the test runner against each one sequentially or in parallel.

Leveraging tools like Lerna or Nx, which are common in monorepos, can help orchestrate the building and testing of individual packages, ensuring that test-storybook is executed correctly for each component library, contributing to a robust overall testing strategy for the entire monorepo.

Limitations and Considerations

While the Storybook test runner is a powerful tool, it’s essential to understand its limitations and consider them when designing your testing strategy.

No single testing tool can cover all scenarios, and the test runner is best viewed as a critical part of a comprehensive testing pyramid, complementing rather than replacing other test types.

Not a Replacement for Unit or End-to-End Tests

It’s crucial to understand that the Storybook test runner, while excellent for UI component testing, is not a full replacement for dedicated unit tests or end-to-end E2E tests. Jest mock hook

Unit tests focus on isolating and testing individual functions or small modules, ensuring their internal logic is correct without UI rendering.

E2E tests, on the other hand, simulate full user journeys through your entire application, testing the integration of multiple systems frontend, backend, databases, APIs. The Storybook test runner operates at a level above unit tests it renders components but below E2E tests it focuses on individual components in isolation, not full application flows. For instance, it won’t test if a backend API call works correctly or if data persists in a database.

A balanced testing strategy, recommended by industry experts like Kent C.

Dodds, involves a robust base of unit tests, a significant layer of integration/component tests where the Storybook test runner shines, and a smaller, but critical, set of E2E tests.

Handling External Dependencies and API Calls

The Storybook test runner runs components in isolation, within the Storybook environment. This means that components that rely heavily on external dependencies like APIs, third-party services, or global state e.g., Redux, React Query need careful handling. The best practice is to mock or stub these dependencies within your Storybook stories. For API calls, you can use tools like MSW Mock Service Worker to intercept network requests and return predefined responses, ensuring your components render consistently regardless of the actual backend status. Similarly, for global state, you can wrap your stories with mock providers or context, providing the necessary state for the component to render and interact correctly. Failing to mock external dependencies can lead to flaky tests, as their success becomes dependent on the availability and state of external services, which is undesirable in an isolated testing environment.

Visual Regression vs. Functional/A11y Testing

While the Storybook test runner checks for accessibility and functional interactions, it does not inherently perform pixel-perfect visual regression testing out of the box.

Its “snapshot” capabilities generally refer to DOM snapshots comparing the HTML structure, not visual image comparisons. This is a common point of confusion.

For true visual regression testing, where you compare screenshots of your components against baseline images to detect unintended visual changes, you would need to integrate dedicated visual testing tools.

Popular options include Chromatic developed by Storybook’s creators, offering robust cloud-based visual testing, Percy, or even integrating image snapshot libraries with Jest e.g., jest-image-snapshot. The Storybook test runner is excellent for verifying that your components are functionally sound and accessible, but for ensuring pixel fidelity across deployments, a complementary visual regression strategy is required.

Building a Robust UI Testing Strategy

A truly robust UI testing strategy doesn’t rely on a single tool but orchestrates several, each playing a specific role in ensuring quality.

The Storybook test runner is a foundational piece, especially for component-level reliability, but it thrives when integrated into a broader ecosystem of testing practices.

This holistic approach ensures that your UI components are not only visually appealing and functional but also maintainable, accessible, and performant over time.

The Testing Pyramid and Storybook’s Role

The testing pyramid is a well-established metaphor in software development that suggests writing different types of tests in varying quantities. It advocates for a large base of fast, isolated unit tests, a middle layer of integration/component tests, and a smaller apex of slower, more comprehensive end-to-end E2E tests. The Storybook test runner perfectly fits into the middle layer of this pyramid. It excels at testing individual UI components in isolation, verifying their rendering, interactions, and accessibility. By treating each Storybook story as an integration test, you gain confidence that your UI building blocks are solid. This allows your more expensive E2E tests to focus purely on critical user flows and system integrations, without duplicating the effort of thoroughly testing individual components. For instance, a typical project might have 60% unit tests, 30% Storybook-driven component tests, and 10% E2E tests.

Complementary Testing Tools

To build a truly comprehensive UI testing strategy, the Storybook test runner should be complemented by other specialized tools:

• Jest for unit tests: For testing pure functions, utility modules, and isolated logic that doesn’t involve UI rendering. It’s fast and provides a rich assertion library.
• Cypress or Playwright for End-to-End tests: These tools simulate full user journeys across your application. They interact with your deployed application in a real browser, verifying integrations between frontend, backend, and third-party services. For example, a Cypress test might verify that a user can successfully log in, navigate to a dashboard, and submit a form.
• Chromatic or Percy for Visual Regression: As discussed, these tools are dedicated to comparing screenshots of your UI components against a baseline, detecting any unintended visual changes e.g., changes in layout, typography, colors, or spacing. Chromatic integrates particularly well with Storybook, providing an automated visual testing workflow directly from your stories. In 2023, Chromatic processed over 150 million UI component snapshots for its users, highlighting its scale and adoption.
• Lighthouse for Performance & SEO: While not strictly a “testing” tool in the traditional sense, Lighthouse provides valuable audits for web performance, accessibility, best practices, and SEO. Running Lighthouse audits on your Storybook build can provide insights into how your components contribute to overall application quality.

By strategically combining the Storybook test runner with these complementary tools, development teams can achieve a multi-faceted testing strategy that covers all aspects of UI quality, from granular component behavior to full-application user experiences, ensuring a robust and delightful user interface.

Storybook and Accessibility: A Powerful Combination

Accessibility a11y is not just a feature.

It’s a fundamental aspect of inclusive design and a legal requirement in many jurisdictions.

The Storybook test runner’s built-in accessibility checks, powered by axe-core, make it an indispensable tool for building accessible UIs.

This integration ensures that accessibility is considered early and often in the development process, rather than being an afterthought.

Proactive Accessibility Checks with Axe

The Storybook test runner automatically integrates with axe-core, the accessibility engine developed by Deque Systems.

As the test runner iterates through each of your Storybook stories, it runs axe-core checks against the rendered component.

This means that common accessibility violations, such as insufficient color contrast a common WCAG 2.1 failure, affecting over 80% of websites according to various reports, missing alternative text for images, incorrect ARIA attributes, or improper heading structures, are automatically detected.

The test runner will report these violations directly in your terminal, often providing links to detailed explanations and remediation guidance.

This proactive approach allows developers to catch and fix accessibility issues at the component level, significantly reducing the cost and effort of remediation compared to discovering them during later stages of development or after deployment.

It’s a continuous feedback loop that promotes building accessibility into the core of your UI components.

Crafting Accessible Stories and play Functions

While automated tools are excellent for catching many accessibility issues, they cannot replace manual testing and thoughtful design.

Developers play a crucial role in crafting accessible stories and play functions that accurately represent accessible interactions.

• Variations for Accessibility States: Create specific stories that demonstrate accessible states, such as focus management, keyboard navigation, and proper ARIA live region announcements. For example, a Button component might have stories for Default, Disabled, Focused with keyboard, and With ARIA label.
• Keyboard Interaction Tests: Within your play functions, simulate keyboard interactions using userEvent.tab, userEvent.keyboard'{enter}', or userEvent.keyboard'{space}'. Assert that components react correctly to keyboard input and that focus is managed appropriately. For instance, a Modal component’s play function could open the modal, tab through its interactive elements, and assert that focus is trapped within the modal and returns to the triggering element upon closing.
• ARIA Attribute Assertions: Use Testing Library to assert the presence and correct values of ARIA attributes. For example, expectscreen.getByRole'alert'.toHaveAttribute'aria-live', 'polite' ensures a dynamically updated region is announced to screen readers.
• Color Contrast Verification beyond automation: While axe-core checks basic contrast, sometimes nuanced design decisions can benefit from manual verification with color contrast checkers. Educate yourself on WCAG contrast guidelines e.g., AA level for text is 4.5:1, AAA is 7:1.
• Descriptive Story Names: Ensure your story names and descriptions clearly explain the component’s purpose and how it handles accessibility concerns. This documentation itself aids in understanding and verifying accessibility.

By combining the automated power of axe-core within the Storybook test runner with intentional, human-driven accessible story design and play functions, teams can significantly elevate the accessibility of their UI components, leading to a more inclusive and compliant user experience for everyone.

Future Trends and Evolution

The Storybook test runner, as a core part of the Storybook ecosystem, is poised to evolve alongside these trends, incorporating new capabilities and adapting to emerging needs.

Component-Driven Development and Test-Driven Design

The Storybook test runner is a natural fit for Component-Driven Development CDD, a methodology that advocates for building UIs from the bottom up, starting with isolated components. CDD, championed by Storybook, encourages thinking about UI in terms of reusable, atomic pieces. When combined with the test runner, this philosophy extends to Test-Driven Design TDD at the component level. Developers can write stories and their play functions which effectively act as component-level tests before implementing the full component logic. This “test-first” approach for components ensures that each building block is well-defined, robust, and performs as expected in isolation. As CDD gains further traction, the test runner’s role in enabling TDD for UI will become even more pronounced, leading to higher quality and more maintainable component libraries.

AI/ML in UI Testing

The burgeoning field of Artificial Intelligence and Machine Learning is slowly but surely making its way into UI testing.

While still in early stages for practical everyday use, we can anticipate future enhancements to tools like the Storybook test runner leveraging AI for:

• Smart Story Generation: AI could analyze component code and suggest new stories to cover missing states or edge cases, reducing the manual effort of story creation.
• Anomaly Detection in Visual Regression: Instead of simple pixel comparison, AI could learn “acceptable” variations in UI e.g., subtle font rendering differences across browsers and flag only “true” visual regressions that indicate a significant unintended change.
• Predictive Accessibility: AI might identify potential accessibility pitfalls based on component structure or common anti-patterns even before axe-core runs, providing earlier warnings.
• Automated Interaction Sequence Generation: For play functions, AI could potentially analyze component props and common user flows to suggest sequences of interactions, improving test coverage for complex components.
• Flaky Test Analysis: ML models could help identify patterns in flaky tests, providing insights into underlying causes e.g., race conditions, timing issues that are hard for humans to pinpoint.

While widespread adoption is still a few years out, the integration of AI/ML could transform the efficiency and effectiveness of UI testing, making the Storybook test runner an even more powerful ally in the quest for perfect UIs.

The future of UI testing points towards increasingly intelligent, automated, and proactive tools that empower developers to build robust and user-friendly interfaces with greater confidence and speed.

Frequently Asked Questions

What is the Storybook test runner?

The Storybook test runner is an open-source utility that leverages your existing Storybook stories as test cases.

It runs your Storybook in a headless browser, executes each story, and performs automated accessibility and interaction tests, ensuring your UI components are functional and accessible.

How does the Storybook test runner work?

It works by launching a headless browser typically Playwright, navigating to your running or built Storybook instance, and then iterating through every story.

For each story, it waits for it to render, runs axe-core for accessibility checks, and executes any defined play functions which contain interaction simulations and assertions.

What types of tests can the Storybook test runner perform?

The Storybook test runner primarily performs functional and accessibility tests.

It verifies that components render correctly, react to user interactions as expected via play functions, and adhere to common accessibility standards via axe-core.

Is the Storybook test runner a replacement for Jest or Playwright?

No, it’s not a replacement. It complements Jest and Playwright.

The test runner uses Jest under the hood for assertions and often leverages Playwright as its headless browser.

It focuses on component-level UI testing, whereas Jest is a general-purpose JavaScript testing framework, and Playwright is an end-to-end testing tool for full application flows.

How do I install the Storybook test runner?

You can install it as a development dependency using npm or yarn: npm install --save-dev @storybook/test-runner jest @testing-library/jest-dom @testing-library/react or yarn add --dev @storybook/test-runner jest @testing-library/jest-dom @testing-library/react.

How do I run Storybook tests?

You typically add a script to your package.json, for example: "test-storybook": "test-storybook". Then, for local development, you run npm run storybook in one terminal and npm run test-storybook in another.

For CI, you build Storybook statically, serve it, and then run the test runner against the served URL.

Can the Storybook test runner perform visual regression testing?

Not directly with pixel-perfect comparisons.

The test runner performs DOM snapshot testing comparing HTML structure if configured with Jest snapshots.

For true pixel-based visual regression, you need to integrate dedicated tools like Chromatic, Percy, or jest-image-snapshot.

What are play functions in Storybook?

play functions are asynchronous functions defined within a Storybook story.

They execute after a story renders and allow you to simulate user interactions e.g., clicks, typing and make assertions using Testing Library and Jest, effectively turning your stories into interactive test cases.

How does the Storybook test runner help with accessibility?

It integrates axe-core out of the box.

When running tests, it automatically checks each rendered story for common accessibility violations e.g., color contrast issues, missing ARIA attributes, improper heading levels and reports them, promoting proactive accessibility development.

Can I run the Storybook test runner in a CI/CD pipeline?

Yes, it’s designed for CI/CD integration.

The common approach is to build a static Storybook build-storybook, serve it using a static server, and then run test-storybook against the served URL within your CI environment.

What are the benefits of using the Storybook test runner?

Key benefits include: leveraging existing stories as tests, ensuring UI consistency, automated accessibility checks, reducing redundant testing efforts, faster feedback loops for component changes, and improved component quality and maintainability.

Does the Storybook test runner support different frameworks like React, Vue, Angular?

Yes, the Storybook test runner is framework-agnostic.

As long as your components are rendered within Storybook, the test runner can interact with them, regardless of whether they are built with React, Vue, Angular, Svelte, or others.

How do I debug failed tests with the Storybook test runner?

When a test fails, the runner provides detailed Jest error messages.

You can then navigate to the specific story in your browser to inspect it visually.

For play functions, you can add console.log statements or use Playwright’s debugging capabilities to step through interactions.

Can I filter which stories the test runner executes?

Yes, you can filter stories using command-line arguments like --stories-url to specify a single story’s URL or --pattern to run stories matching a specific title or ID regex.

This is useful for focused development or faster feedback.

How does the Storybook test runner handle external dependencies like API calls?

Components relying on external dependencies should have those dependencies mocked or stubbed within their Storybook stories.

Tools like Mock Service Worker MSW are excellent for intercepting and faking API responses in Storybook, ensuring tests are isolated and consistent.

What is the performance impact for large Storybooks?

For large Storybooks, performance can be optimized.

The test runner supports parallelization using the --workers flag to run tests concurrently.

Ensuring stories load quickly and mocking heavy dependencies also significantly improves performance.

Does the Storybook test runner provide code coverage?

No, the Storybook test runner itself does not provide code coverage.

Code coverage is typically handled by your Jest configuration or other tools that analyze your source code during test runs.

How does it compare to end-to-end testing tools like Cypress or Playwright?

The Storybook test runner focuses on isolated component testing, ensuring individual UI blocks work correctly.

Cypress and Playwright are designed for end-to-end tests, simulating full user journeys across an entire application, including backend integrations and navigation between pages.

They serve different purposes in the testing pyramid.

Can I use the Storybook test runner with TypeScript?

Yes, the Storybook test runner works seamlessly with TypeScript projects.

Your stories and play functions can be written in TypeScript, and the runner will execute them correctly after compilation.

What are some best practices for using the Storybook test runner effectively?

Best practices include: writing clear, isolated stories for every component state. utilizing play functions for interactive tests. mocking external dependencies. integrating it into CI/CD for automated checks.

And pairing it with visual regression tools for comprehensive UI quality assurance.