Adding TypeScript to existing ReactJS application

Create ReactJS app with TypeScript

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2 min read

You already have running React app, and wanted to add TypeScript to it, Must of the cases, there is a high possibility of your app to break, unfortunately :( In this guide, I will show you how to add it with much work and your app will run perfectly without breaking.

Generating React App with TypeScript

npx create-react-app app-name --template typescript

or

yarn create react-app app-name --template typescript

Installing TypeScript to existing React project

First stop the running React app if it is running

Then run the following command in your Terminal (For Mac/Linux) or CMD (For PC)

npm install --save typescript @types/node @types/react @types/react-dom @types/jest

or run

yarn add typescript @types/node @types/react @types/react-dom @types/jest

if you are using yarn Now, try running the application with

npm start

or

yarn start

if it doesn't work, then you might need to delete your node_module folder and package-lock.json file, then install the dependencies again with

npm install

if you are using npm or

yarn add

if you are using yarn Now, run the app again.

If still, it didn't work, then you need to generate tsconfig.json manually with

npx tsc --init

but you need to get TypeScript to install in your machine globally, if you don't, run

npm install -g typescript

or

yarn add typescript

Now, run the application. Wolla :) It works

Now you can change App.js or App.jsx to App.tsx Immediately you do that, your app might break again, so start typing all your javascript or check out TypeScript official docs

Hola!

TypeScript is set, up and running, for full docs, visit Here to get started with Typescript

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