Migrating Incrementally
Adopt TS gradually: enable checks, annotate with JSDoc, migrate hot files first, and keep builds green during the transition.
Migrating Incrementally is a free React Academy lesson on CoddyKit — lesson 3 of 3. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the React Academy learning path, one of 3 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Why incremental migration?
Goal: Ship while you migrate.
- Add checks without breaking builds
- Annotate with JSDoc
- Migrate hot files first
Plan the migration
- Start with JSDoc on JS files
- Keep changes small; one component at a time
- Focus on frequently edited files
- Use type aliases to reuse shapes
Step 1: props via JSDoc
Add JSDoc to document props without renaming the file.
<div id="root"></div>Step 2: shared typedef reuse
Extract a shared typedef and reuse it everywhere.
<div id="root"></div>Step 3: runtime guard pattern
Use a small guard to keep runtime safe during migration.
<div id="root"></div>Tips & checklist
- Migrate file-by-file; keep PRs small
- Add JSDoc now; rename to TS later
- Use tiny guards while types settle
Incremental migration check
Recap
Recap: Start with JSDoc in JS files, extract shared typedefs, add tiny runtime guards, and then rename hot files to TS when ready.
Frequently asked questions
Is the “Migrating Incrementally” lesson free?
Yes — the full text of “Migrating Incrementally” is free to read here on the web, and the React Academy course includes 3 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the React Academy course, upgrade to CoddyKit PRO.
What will I learn in “Migrating Incrementally”?
Adopt TS gradually: enable checks, annotate with JSDoc, migrate hot files first, and keep builds green during the transition. You practise React Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start React Academy?
No prior experience is required. React Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 3 of 3, so you can start here or from the beginning and move at your own pace.
How long does the “Migrating Incrementally” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this React Academy lesson?
Yes. Every React Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.
All lessons in this course
- Props Typing & Generics for Reusable Components
- Event Types, Refs, and Context Typing
- Migrating Incrementally