I Let an AI Write My Tests for 30 Days: Coverage Went 38% to 71%

Here's the number that surprised me: 30 days, zero tests written by hand, coverage from 38% to 71%.

I handed test-writing to an open-source AI agent (search the-agent on GitHub) and let it generate, run, and maintain my tests from natural-language descriptions. This is the full account — the workflow, the configs, the pitfalls, and the honest trade-offs.

Why I Tried This

Last month I broke 35 tests by changing one function signature. Fixing them took until lunch. The pain wasn't writing tests — it was maintaining them: normal inputs, edge cases, error branches, and the worst part — that false confidence of "all green" when critical paths were never covered.

I saw the-agent trending on GitHub (a prompt-based test automation tool that uses AI agents to generate, run, and maintain tests) and decided to run a real 30-day experiment.