Lesson 1220 of 1596
AI coding: refactor safely by stating invariants
Tell the AI what must stay true after the refactor — call signature, side effects, performance bounds — and it stops introducing surprises.
Creators · AI-Assisted Coding · ~7 min read
The premise
Refactor prompts fail when the AI optimizes the wrong axis. Stating explicit invariants — what must not change — keeps the rewrite focused on the dimension you actually want improved.
What AI does well here
- Preserve a documented public API while restructuring internals
- Apply a named pattern (extract method, strategy) consistently
- Diff old vs new behavior when given both
What AI cannot do
- Guarantee semantic equivalence across complex side effects
- Detect performance regressions without benchmarks
- Know which 'cleanups' your team actually accepts
Key terms in this lesson
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