Playwright Locators

Playwright Locators are strategies used to identify elements on a webpage, enabling interaction with them in automated tests. They offer robust and reliable element selection, reducing test flakiness.

Detailed explanation

Playwright locators are a fundamental aspect of writing reliable and maintainable end-to-end tests. They provide a powerful and flexible way to identify elements within a web page's DOM (Document Object Model). Unlike traditional methods like XPath or CSS selectors, Playwright locators are designed to be resilient to changes in the application's UI, minimizing test failures due to minor modifications.

Playwright offers several built-in locator strategies, each with its strengths and weaknesses. Choosing the right locator strategy is crucial for creating stable and efficient tests. Here's a breakdown of the most commonly used locators:

  • getByRole(): This locator is the recommended approach whenever possible. It identifies elements based on their semantic role, as defined by ARIA (Accessible Rich Internet Applications) attributes. This makes tests more accessible and less prone to breaking due to styling changes.

    // Example: Locating a button with the role "button" and name "Submit"
await page.getByRole('button', { name: 'Submit' }).click();

    This approach is preferred because it focuses on the purpose of the element rather than its specific implementation details. If the button's styling changes, but it still functions as a button with the name "Submit," the test will continue to pass.

  • getByText(): This locator finds elements containing specific text. It's useful for locating headings, labels, or other elements with visible text content.

    // Example: Locating an element containing the text "Welcome to our website"
await page.getByText('Welcome to our website').isVisible();

    While convenient, getByText() can be less reliable if the text content changes frequently. It's best used for static text or when other locator strategies are not suitable.

  • getByLabel(): This locator finds form elements associated with a specific label. It's particularly useful for interacting with input fields, checkboxes, and radio buttons.

    // Example: Locating an input field with the label "Email Address"
await page.getByLabel('Email Address').fill('test@example.com');

    This locator ensures that the test interacts with the correct form element, even if the HTML structure changes.

  • getByPlaceholder(): This locator finds input elements with a specific placeholder attribute.

    // Example: Locating an input field with the placeholder "Search..."
await page.getByPlaceholder('Search...').fill('Playwright');

    Similar to getByText(), this locator relies on the placeholder text remaining consistent.

  • getByAltText(): This locator finds image elements with a specific alt attribute.

    // Example: Locating an image with the alt text "Company Logo"
await page.getByAltText('Company Logo').click();

    Using getByAltText() improves accessibility and makes tests more robust.

  • getByTitle(): This locator finds elements with a specific title attribute.

    // Example: Locating an element with the title "Learn More"
await page.getByTitle('Learn More').hover();

    This locator is useful for interacting with elements that provide additional information on hover.

  • CSS Selectors: Playwright also supports traditional CSS selectors. While powerful, CSS selectors can be more brittle than the other locator strategies, as they rely on the specific HTML structure.

    // Example: Locating an element with the ID "my-element"
await page.locator('#my-element').click();

    Use CSS selectors sparingly and prefer the other locator strategies whenever possible.

  • XPath: Similar to CSS selectors, Playwright supports XPath expressions. XPath can be useful for navigating complex DOM structures, but it's generally less readable and maintainable than other locator strategies.

    // Example: Locating an element using an XPath expression
await page.locator('//div[@class="my-class"]/a').click();

    Avoid using XPath unless absolutely necessary.

Combining Locators:

Playwright allows you to combine multiple locators to create more specific and reliable element selections. This is particularly useful when dealing with complex UI structures.

// Example: Locating a button with the role "button" and containing the text "Submit" within a specific div
await page.locator('div#my-container').getByRole('button', { name: 'Submit' }).click();

In this example, we first locate the div element with the ID "my-container" and then use getByRole() to find the button within that container.

Best Practices:

  • Prioritize getByRole(): Always try to use getByRole() first, as it's the most resilient and accessible locator strategy.
  • Use specific locators: Avoid using overly generic locators that could match multiple elements.
  • Test locator resilience: Regularly review your locators to ensure they remain valid as the application's UI evolves.
  • Use descriptive names: Give your locators meaningful names to improve code readability.
  • Avoid relying on implementation details: Focus on the user's perspective when choosing locators.

By following these best practices, you can create Playwright tests that are robust, maintainable, and less prone to failure. Choosing the right locator strategy is a key factor in achieving reliable end-to-end testing.

Further reading

Related Terms

A/B Testing

Acceptance Testing

Accessibility Tester