Mutation testing is AWESOME

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• Mutation testing is presented as an “awesome” and essential method for ensuring a high-quality and rigorous test suite, particularly beneficial for agents.
• The process involves making small “mutations” to source code (e.g., changing a string to empty) and then rerunning tests; “surviving mutants” are those mutations that don’t cause tests to fail, indicating a gap in test coverage that needs to be “killed.”
• This technique provides rich feedback, leading to more robust tests that reliably catch potential bugs. Tools like Striker.js are available for TypeScript, with many other options for different languages.