I'm trying to add typescript
to my project and write new components with typescript. I followed the documentation but I'm got this error:
can't resolve [the typescript file]
this happens even with a fresh create-react-app
project.
according to CRA documentation for adding typescript
To an existing Create React App project, first, we must install typescript
and type definition files
:
npm install --save typescript @types/node @types/react @types/react-dom @types/jest
almost done!
rename a js/jsx
file to tsx
and restart your development server!
for simplicity, I'm creating a typescript
file named test.tsx
that contains the Test
component:
export default function Test(){
return (
<div>this is test to see typescirpt</div>
)
}
and importing it to the main.js
and rendering it:
import Test from "./test";
function App() {
return (
<div className="App">
<Test />
</div>
);
}
export default App;
now I'm restarting the development server (I closed the previous one with CRTL+c
) with npm start
.
I got this error:
Compiled with problems:
ERROR in ./src/App.js 4:0-26
Module not found: Error: Can't resolve './test' in '/home/g/w/ts/test_adding_ts/src'
I used a fresh create-react-app
project, followed the documentation, and saw this error. (why?)
this is my installed dependencies:
"dependencies": {
"@testing-library/jest-dom": "^5.16.4",
"@testing-library/react": "^13.0.1",
"@testing-library/user-event": "^13.5.0",
"@types/jest": "^27.4.1",
"@types/node": "^17.0.24",
"@types/react": "^18.0.5",
"@types/react-dom": "^18.0.1",
"react": "^18.0.0",
"react-dom": "^18.0.0",
"react-scripts": "5.0.1",
"typescript": "^4.6.3",
"web-vitals": "^2.1.4"
},
Have you created a config file: tsconfig.json in your root directory? I didn't see this being mentioned in the question.
tsconfig.json
{
"compilerOptions": {
"target": "es5",
"lib": [
"dom",
"dom.iterable",
"esnext"
],
"allowJs": true,
"skipLibCheck": true,
"esModuleInterop": true,
"allowSyntheticDefaultImports": true,
"strict": true,
"forceConsistentCasingInFileNames": true,
"noFallthroughCasesInSwitch": true,
"module": "esnext",
"moduleResolution": "node",
"resolveJsonModule": true,
"isolatedModules": true,
"noEmit": true,
"jsx": "react-jsx"
},
"include": [
"src"
]
}
If not created, you can create one in root directory alongside package.json and paste the above configs. OR else already created, you can replace the existing config by above config and recheck.
CRA Documentation guide works if follow each step as is but it's very tricky when saying "rename any file to be a TypeScript file". According to source code of create-react-app
to use typescript your app should contain ./tsconfig.json
file.
Simple renaming, as described in guide, works only for ./src/index.(js|ts|jsx|tsx)
file but all imports will fail as far as create-react-app
configurates webpack
to exclude all typescript files.
Minimal ./tsconfig.json
file, as I personally checked for CRA version 5.0.1 is a following one:
{
"compilerOptions": {
"esModuleInterop": true,
"jsx": "react"
}
}
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With