I Replaced Cypress With an AI Testing Agent for 2 Weeks — Here's the Honest Data

I Replaced Cypress With an AI Testing Agent for 2 Weeks — Here's the Honest Data AI writes 42% of new code in production codebases. But most teams still test that code the same way they did in 2020: manually written Cypress scripts, brittle selectors, and a CI pipeline that screams at 3 AM because someone renamed a CSS class. I spent two weeks testing TestSprite — an AI testing agent that generates, runs, and fixes tests autonomously — alongside my existing Cypress and Playwright setup. Here's what actually happened. The Setup: Three Real Projects Project 1 : React dashboard with auth (Claude Code-generated components) TestSprite found 14 edge cases I missed: race conditions in auth flow, state leaks, error boundary gaps Pass rate: 42% → 91% after one fix cycle Project 2 : REST API with complex validation (OpenAPI spec) 47 auto-generated test cases covering every endpoint Caught an unguarded admin endpoint and a timezone parsing bug Pass rate: 38% → 89% Project 3 : E-commerce checkout