XPath

XPath (XML Path Language) is a query language for navigating and selecting nodes in HTML/XML documents. In test automation, it's one of the primary methods for locating web elements.

XPath types:

• Absolute XPath: Full path from root — `/html/body/div[1]/form/input[2]` (fragile, avoid)
• Relative XPath: Starts anywhere — `//input[@id='email']` (preferred)

Useful XPath patterns:

• By attribute: `//input[@name='email']`
• By text: `//button[text()='Submit']`
• Contains: `//div[contains(@class, 'error')]`
• Parent/child: `//div[@class='form']//input`
• Sibling: `//label[text()='Email']/following-sibling::input`
• Index: `(//button)[2]` — second button on page

XPath vs CSS selectors:

• XPath can traverse up the DOM (parent::) — CSS cannot
• XPath can select by text content — CSS cannot
• CSS selectors are generally faster
• CSS syntax is more readable

Best practice: prefer ID and CSS selectors when available, use XPath when you need text-based or parent-traversal selection.