A Java library just tried to trick AI coding agents into deleting your tests, and it almost worked

The Java testing library jqwik shipped a hidden instruction in version 1.10.0 aimed at AI coding agents.

The message told agents to delete jqwik tests and code, and used ANSI escape sequences to hide it from human terminal view.

A developer reported the behavior, triggering criticism and concern about prompt injection in agent-driven workflows.

jqwik’s documentation was later updated to explain the tactic and clarify the library is not intended for AI coding agents.