What problem does it solve? Verifying browser-facing changes by hand or with raw browser tools often confirms only the happy path, letting edge-case bugs reach production. This Skill runs adversarial browser tests that actively try to break your changes and report structured pass/fail results. ## Core Features & Use Cases - Adversarial Test Plans: Generates tests targeting empty inputs, invalid data, boundary values, double-clicks, and navigation edge cases rather than simple render checks. - Structured Failure Output: Reports the exact failing step and what broke, so fixes are fast and verifiable. - Session and Auth Support: Provides session recordings, cookie/auth injection, and configurable base URLs via EXPECT_BASE_URL or --base-url. - Use Case: After changing a checkout flow, run expect-cli with instructions to submit valid data, then attempt empty-cart submission, invalid card numbers, double-click order placement, and back-button mid-payment, verifying error states and console errors. ## Quick Start Ask the AI to run expect-cli with an adversarial instruction against your local app, for example to test the login form with empty, invalid, and valid credentials and verify error messages and redirects.