# Thirtyfour

Use this checklist when asking a coding agent to write or review `thirtyfour` automation. It is intentionally short enough to paste into project-level agent instructions:

## AI Automation Guide

### Reliable AI-Generated Tests

Path: `/thirtyfour/getting-started/reliable-tests.html`

Use this checklist when asking a coding agent to write or review `thirtyfour` automation. It is intentionally short enough to paste into project-level agent instructions:

Use this checklist when asking a coding agent to write or review thirtyfour automation. It is intentionally short enough to paste into project-level agent instructions: Copy - Use WebDriver::managed for local browsers; use WebDriver::new or builder only when connecting to a remote Selenium or Grid endpoint. - Use query() for normal lookup. Use find() only for an intentional one-shot lookup. - End unique queries with single(), and add desc(...) to important queries. - Prefer By::Testid or another stable app-owned selector. Avoid generated classes, DOM-position chains, and XPath when stable CSS can express the target. - Never use a fixed sleep for page readiness. Wait with query() or wait_until(). - Scope queries through a container element; use Components for repeated UI areas. - Explicitly call driver.quit().await? when the session is finished. - Do not share one WebDriver session across independent concurrent flows. A shared WebDriverManager may launch separate sessions for parallel tests. - Keep CDP and BiDi code isolated from portable WebDriver flows. Gate optional cdp-events and bidi APIs with their Cargo features, and opt BiDi sessions in. Why These Rules WebDriver::managed downloads, launches, and lifetime-manages a local driver. Use the normal constructor or WebDriver::builder when an external Selenium service owns that lifecycle. Explicit quit() reports shutdown errors and does not rely on asynchronous cleanup during Drop . Element queries poll for page state and provide filters, descriptions, and cardinality checks. See the guidance for stable selectors , choosing single() or first() , describing important queries , and intentional one-shot lookup . Element waits express the state an existing element must reach. A fixed sleep only guesses how long the page needs; a query or wait completes as soon as the required state exists and produces a useful timeout when it does not. Element-scoped queries prevent unrelated matches. For recurring UI areas, Components keep selectors private and expose user-intent methods while their resolvers handle polling and stale elements. A cloned WebDriver controls the same browser session, so independent flows can race over tabs, navigation, and browser state. The manager's shared configuration can instead launch a separate session for each test or worker. CDP is Chromium-specific, while BiDi is the cross-browser W3C protocol. Keep either behind a small boundary so the rest of the automation remains portable, and follow the feature flag and BiDi opt-in requirements. The cdp feature is enabled by default; cdp-events and bidi are opt-in. Treat these as review rules, not merely generation hints: generated code should not be accepted until its selectors, waits, cleanup, concurrency, and feature gates satisfy the same checklist.