firebase/firebase-js-sdk Issue #6928

firebase/firebase-js-sdk#6928

This might also be a PNPM issue, I am not 100 % sure I also opened an issue with them:

pnpm/pnpm#5912

Steps To Reproduce

Note that I have only tried this on macOS, not sure if it happens on Windows or Linux.

This works well

• npx create-next-app
  • Name: my-app-npm
  • TypeScript: Yes (default)
  • ESLint: Yes (default)
• cd my-app-npm
• npm install firebase
• Go to pages/_app.tsx and add this line: import { initializeApp } from 'firebase/app'
• Command/Control-click through firebase/app in _app.tsx
• Land on node_modules/firebase/app/dist/app/index.d.ts
• Command/Control-click through @firebase/app in index.d.ts
• Land on node_modules/@firebase/app/dist/app-public.d.ts
• Add "preserveSymlinks": true in tsconfig.json's compilerOptions
• Press Control/Command+Shift+P and select Developer: Reload Window
• Observe that these steps still work as expected after that

Everything still works with NPM.

It doesn't work with PNPM and "preserveSymlinks": true

• pnpm create next-app
  • Name: my-app-pnpm
  • TypeScript: Yes (default)
  • ESLint: Yes (default)
• cd my-app-pnpm
• pnpm install firebase
• Go to pages/_app.tsx and add this line: import { initializeApp } from 'firebase/app'
• Command/Control-click through firebase/app in _app.tsx
• Land on node_modules/.pnpm/firebase@9.15.0/node_modules/firebase/app/dist/app/index.d.ts
• Command/Control-click through @firebase/app in index.d.ts
• Land on node_modules/.pnpm/@firebase+app@0.9.0/node_modules/@firebase/app/dist/app-public.d.ts
• Add "preserveSymlinks": true in tsconfig.json's compilerOptions
• Press Control/Command+Shift+P and select Developer: Reload Window
• Notice initializeApp in _app.tsx now shows a type error:

  'initializeApp' is declared but its value is never read. ts(6133) Module '"firebase/app"' has no exported member 'initializeApp'. ts(2305)

• Command/Control-click through firebase/app in _app.tsx
• Land on node_modules/firebase/app/dist/app/index.d.ts
• Try to command/control-click through @firebase/app in index.d.ts
• Notice that nothing happens - VS Code / TypeScript can't resolve the import

When using PNPM with "preserveSymlinks": true, an error occurs.