reuse-first

name	reuse-first
description	The search-before-you-build workflow for this library. Use whenever you are about to add a new function, class, type, or kit, or when asked to implement any capability — to avoid duplicating one of the 15,000+ existing exports.

Reuse-first workflow

This is a reusable function library. The most expensive mistake here is shipping a function that already exists under a different name. Every "implement X" request starts with "does X already exist?"

1. Search before writing — always

Generate several candidate terms (verb, noun, synonyms), then:

npm run search "rate limit"     # case-insensitive keyword sweep across *.ts
npm run find "createRateLimiter" # literal symbol
npm run find:function           # every exported function
grep -rn "export .*Throttle" --include='*.ts'

Also scan the catalogs, which index public exports: FUNCTION-CATALOG.md, MASTER-INDEX.md, QUICK-REFERENCE.md, NAVIGATION.md.

For anything non-trivial, delegate the search to the kit-explorer subagent (or run /find-kit "<capability>") so the file reading stays out of your main context and you get back just the verdict + import paths.

2. Decide: reuse / extend / compose / build

• EXISTS → import it (import { x } from '@reuse/<domain>/<area>') and stop.
• PARTIAL → extend or compose existing kits rather than starting fresh.
• NOT FOUND (only after trying synonyms + catalogs) → build it, following the kit-conventions skill, in the right domain (core/domain-shared if cross-cutting).

3. Place it where others will find it

A new function only counts as "reusable" if it's discoverable and importable:

• Wire it up the index.ts barrel chain to the domain root.
• Give it complete JSDoc with an @example.
• Update the catalog if it's a notable public export.

Anti-patterns

• Writing a util "real quick" without searching → silent duplicate.
• Searching only the exact name you have in mind → miss the synonym that already exists.
• Building in a leaf folder without barrel-exporting → invisible, gets duplicated again later.