How to use typescript in existing Next.js project

Well typescript has won. You probably need to use it if you're working in a team. I'm a solo hobby developer. But I still have a slim chance that I want to change my career. Let's change my project to typescript.

Get started

Create typescript config file

touch tsconfig.json

It creates tsconfig.json file. It's empty but don't worry.

Install packages

npm i -D typescript [@types/react @types/node]

Run the Next.js project

npm run dev

npm run
 
> dev
> next dev
 
ready - started server on 0.0.0.0:3000, url: http://localhost:3000
We detected TypeScript in your project and created a tsconfig.json file for you.

Next.js fills tsconfig.json for you.

If you're not using Next.js, following command will create > and fill the tsconfig.json file

tsc --init

Change file names

Change file names from *.js to *.tsx

Now you're using typescript

More to be added as I gradually convert to typescript...

Before

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After

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