Regression set: meaning, examples, and expert terminology.

Plain meaning

Keeps previous failures and important examples in the test loop so fixes do not silently break later.

Aliases

regression suite, failure replay set, known failures

People usually say

• automatically test my ai agent
• regression set
• regression tests
• replay failures
• keeps breaking
• breaks on similar tasks later

Experts usually say

Regression set, Golden tests, Replay, Eval harness

Use it when

Your rough ask sounds like: automatically test my ai agent, regression set, regression tests. The term gives your coding agent a clearer problem shape.

When not to use it

Do not use this term as a request for a quick screen fix. Use it when the system needs explicit state, rules, failures, or recovery behavior.

Prompt upgrade

Weak ask: Fix this automatically test my ai agent flow.

Exact Terms ask: Maintain a regression set of past failures, edge cases, and important user tasks that every agent change must pass.

Architecture prompt

Audit this workflow for Regression set and related concerns: Golden tests, Replay, Eval harness. Return states, rules, failure modes, and recovery behavior before code.

Implementation prompt

Implement Regression set for this app flow. Include data ownership, edge cases, fallback behavior, and acceptance tests.

Test prompt

Create tests that prove Regression set works across refresh, retry, back/next movement, partial failure, and return visits.

What goes wrong

Asking for code before defining states, transitions, persistence, and failure behavior.

Better move

Use Regression set with the related vocabulary trail: Golden tests, Replay, Eval harness.

Turn feedback into vocabulary

If this page almost names your problem but misses the exact term, send the rough phrase and the term you expected. Accepted feedback becomes a better trigger, explanation, comparison page, or new term.