Pest: The Elegant Testing Framework for PHP Developers and AI Agents

Pest is an elegant PHP testing framework built for PHP developers and AI agents. It provides browser testing, AI evals, an agent browser that verifies coding agents' work end-to-end, and the Tia Engine for near-instant test runs. The framework includes code coverage and mutation testing capabilities, supports migration from PHPUnit, and allows writing and running PHP tests. It offers CLI options such as generating baselines, generating configuration files, generating mutations for specific classes, generating mutations only for covered classes, generating mutations for all classes, ignoring logging, generating code coverage reports, and warming the static analysis cache. Pest is open-source and free, with a public API. It has a medium learning curve and is loved by developers and their agents.