TypeScript Strict Mode Checklist

Strict settings surface bugs at compile time instead of after deploy — worth the migration pain for long-lived apps.

Recommended flags (baseline)

Work toward enabling:

• strict
• noUncheckedIndexedAccess
• exactOptionalPropertyTypes (optional, stricter)

Migration strategy

1. Enable strict on a branch and list errors by directory.
2. Fix shared utilities and types first — ripple effects shrink downstream noise.
3. Add precise types at module boundaries (API responses, Firestore documents).

With Next.js

Co-locate types near data loaders and your article metadata so pages stay honest about optional fields.

Strict TypeScript is not vanity — it is documentation that the compiler enforces.