Practice workspaceY
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INDEPENDENT PRACTICE · TESTING & REFACTORING

Preserve behavior while refactoring

Name and verify invariants before changing structure.

YOUR CHALLENGE

List invariants for a filter utility extraction.

Which observations should stay the same after extracting a function?

Choose the best next action

Independent variant 1. Repeating a solved variant does not increase mastery.

06 / REFLECT

Make the lesson yours.

Your reflection is attached when you submit your decision. Drafts remain in this tab.

07 / TRANSFER

Try it somewhere unfamiliar.

Apply this skill to an unfamiliar repository: list invariants for a filter utility extraction. Record the evidence you would need.

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Source checked 2026-09-09 · Documentation profile · Runtime example untestedOfficial reference