Agent-Written Tests Can Enshrine the Bug: Green Suite, Wrong Code
HiddenTomato1 · reddit · 2026-10-12
A developer shares a practical lesson: an AI agent wrote code and then tests that simply matched the buggy behavior. The suite went green, but deliberately breaking one line still passed — the tests were documenting the bug, not verifying correctness.
His takeaway: before trusting an agent-produced codebase, intentionally break a line after a green suite to check whether the tests actually catch regressions, or fall back to reading the diff. He asks how others validate agent-generated tests.
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