How to add typescript to an existing vite react app?

readme.md

How to add typescript to an existing vite react app?

1. Install typescript, @types/react and @types/react-dom.

npm install --save-dev typescript @types/react @types/react-dom

2. In packages.json, replace vite build with tsc && vite build.

"build": "vite build"

With 👇

"build": "tsc && vite build"

3. Rename vite.config.js and main.jsx to vite.config.ts and main.tsx

4. Configure TypeScript by creating these two files in the root of your project:

tsconfig.json

{
  "compilerOptions": {
    "target": "ESNext",
    "useDefineForClassFields": true,
    "lib": ["DOM", "DOM.Iterable", "ESNext"],
    "allowJs": false,
    "skipLibCheck": true,
    "esModuleInterop": false,
    "allowSyntheticDefaultImports": true,
    "strict": true,
    "forceConsistentCasingInFileNames": true,
    "module": "ESNext",
    "moduleResolution": "Node",
    "resolveJsonModule": true,
    "isolatedModules": true,
    "noEmit": true,
    "jsx": "react-jsx"
  },
  "include": ["src"],
  "references": [{ "path": "./tsconfig.node.json" }]
}

tsconfig.node.json

{
  "compilerOptions": {
    "composite": true,
    "module": "ESNext",
    "moduleResolution": "Node",
    "allowSyntheticDefaultImports": true
  },
  "include": ["vite.config.ts"]
}

5. Create a file named vite-env.d.ts inside the src/ folder and copy and paste this (with the three slashes at the beginning):

/// <reference types="vite/client" />

6. In your index.html you should change the name of your script from the old main.jsx to main.tsx like this:

<script type="module" src="/src/main.tsx"></script>