no service-worker.js file after npm run build in react

Question

After running npm run dev no service-worker.js file in build folder.

I'm also changed serviceWorker.register() in index.js
I'm also using firebase in this project.

Here is package.json file

{
  "name": "movie",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "@testing-library/jest-dom": "^4.2.4",
    "@testing-library/react": "^9.5.0",
    "@testing-library/user-event": "^7.2.1",
    "axios": "^0.20.0",
    "email-verifier": "^0.4.1",
    "firebase": "^7.24.0",
    "history": "^5.0.0",
    "react": "^16.13.1",
    "react-dom": "^16.13.1",
    "react-lottie": "^1.2.3",
    "react-router-dom": "^5.2.0",
    "react-scripts": "^4.0.0"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test",
    "eject": "react-scripts eject"
  },
  "eslintConfig": {
    "extends": "react-app"
  },
  "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  },
  "devDependencies": {
    "@types/react-router-dom": "^5.1.6"
  }
}

After deploy in firebase ,I got this error.

serviceWorker.js:97 Error during service worker registration: DOMException: Failed to register a ServiceWorker for scope ('https://.web.app/') with script ('https://*.web.app/service-worker.js'): The script has an unsupported MIME type ('text/html').

Answer 1

I had the same problem, and solved following these steps in GitHub issue:

It happened after create-react-app upgraded to version 4.x.

The "fix" was to create a dummy app:

npx create-react-app my-app --template cra-template-pwa-typescript

And copy over the relevant code:

reportWebVitals.ts

service-worker.ts

serviceWorkerRegistration.ts

And don't forget the initialization code in index.tsx.