First Thoughts About ReasonML vs TypeScript

Today I finished my first TypeScript experiment with React.

Here are some thoughts after using ReasonReact first, and now TypeScript second.

1. Setup Is Not Better Than ReasonReact

   I used Create React App to bootstrap the app.

   npx create-react-app <project-name> --typescript
   

   But then I had to setup ESLint and Prettier with TypeScript.

   ReasonML & BuckleScript:

   npm install -g bs-platform
   bsb -init <project-name> -theme react-hooks
   

   After that you’re done.

2. It’s JavaScript

   ReasonML is a completely different language than JavaScript. Don’t let the similar syntax fool you.
   TypeScript is “enhanced” JavaScript.

   TypeScript is “easier”, at least at the beginning.

3. The React+TypeScript CheatSheets Are Invaluable

   You should use them.

4. How Do I Get 100% Type-Safety?

   How do you “make impossible states impossible”?

   You’ll soon have to reach for advanced concepts like Discriminated Unions. Those are quite more complicated than their ReasonML equivalent.

   And how do you type Promises?

   It’s incredibly difficult to reach 100% type safety for a beginner. ReasonML provides a better story here.

5. The Code Is Hard To Read

   Type inference doesn’t work as well as in ReasonML/OCaml. As a consequence, you have to define types explicitly.

   The code is quite verbose and harder to read.

Further Reading

• Create React App: Adding TypeScript
• Using ESLint and Prettier in a TypeScript Project
• React+TypeScript Cheatsheets
• Making Impossible States Impossible