je ne peux pas démarrer un projet react native en utilisant npm/expo start

Question

Suivant docs react-native pour créer une application Android après avoir utilisé

npm install -g expo-cli

et dans le même fichier de projet en utilisant

expo init first-proj

cd first-proj

tout va bien jusqu'à ce que je le fasse npm start cela va me donner une erreur

> first-proj@1.0.0 start
> expo start

Starting project at D:\react\react projects\reacttest\first-proj
Unable to find expo in this project - have you run yarn / npm install yet?

et j'ai donc téléchargé npm en utilisant npm install mais maintenant ça donne un autre problème. Lorsque je tape npm start il montre ceci dans le terminal du code vs

> first-proj@1.0.0 start
> expo start

node:internal/modules/cjs/loader:936
  throw err;
  ^

Error: Cannot find module './util/resolveCommand'
Require stack:
- D:\react\react projects\reacttest\first-proj\node_modules\cross-spawn\lib\parse.js
- D:\react\react projects\reacttest\first-proj\node_modules\cross-spawn\index.js
- D:\react\react projects\reacttest\first-proj\node_modules\expo\bin\cli.js
    at Function.Module._resolveFilename (node:internal/modules/cjs/loader:933:15)
    at Function.Module._load (node:internal/modules/cjs/loader:778:27)
    at Module.require (node:internal/modules/cjs/loader:1005:19)
    at require (node:internal/modules/cjs/helpers:102:18)
    at Object.<anonymous> (D:\react\react projects\reacttest\first-proj\node_modules\cross-spawn\lib\parse.js:5:24)
    at Module._compile (node:internal/modules/cjs/loader:1103:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1155:10)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)
    at Module.require (node:internal/modules/cjs/loader:1005:19) {
  code: 'MODULE_NOT_FOUND',
  requireStack: [
    'D:\\react\\react projects\\reacttest\\first-proj\\node_modules\\cross-spawn\\lib\\parse.js',
    'D:\\react\\react projects\\reacttest\\first-proj\\node_modules\\cross-spawn\\index.js',
    'D:\\react\\react projects\\reacttest\\first-proj\\node_modules\\expo\\bin\\cli.js'
  ]
}

Et si je le fais expo start au lieu de cela, cela donne

Starting project at D:\react\react projects\reacttest\first-proj
Developer tools running on http://localhost:19002
Cannot find module './lib/source-map-generator'
Require stack:
- D:\react\react projects\reacttest\first-proj\node_modules\source-map\source-map.js
- D:\react\react projects\reacttest\first-proj\node_modules\snapdragon\lib\utils.js
- D:\react\react projects\reacttest\first-proj\node_modules\snapdragon\lib\compiler.js
- D:\react\react projects\reacttest\first-proj\node_modules\snapdragon\index.js
- D:\react\react projects\reacttest\first-proj\node_modules\anymatch\node_modules\braces\lib\braces.js
- D:\react\react projects\reacttest\first-proj\node_modules\anymatch\node_modules\braces\index.js
- D:\react\react projects\reacttest\first-proj\node_modules\anymatch\node_modules\micromatch\index.js
- D:\react\react projects\reacttest\first-proj\node_modules\anymatch\index.js
- D:\react\react projects\reacttest\first-proj\node_modules\sane\src\common.js
- D:\react\react projects\reacttest\first-proj\node_modules\jest-haste-map\build\lib\WatchmanWatcher.js
- D:\react\react projects\reacttest\first-proj\node_modules\jest-haste-map\build\index.js
- D:\react\react projects\reacttest\first-proj\node_modules\metro\src\node-haste\DependencyGraph.js
- D:\react\react projects\reacttest\first-proj\node_modules\metro\src\Bundler.js
- D:\react\react projects\reacttest\first-proj\node_modules\metro\src\IncrementalBundler.js
- D:\react\react projects\reacttest\first-proj\node_modules\metro\src\index.js
- C:\Users\abdal\AppData\Roaming\npm\node_modules\expo-cli\node_modules\@expo\dev-server\build\metro\importMetroFromProject.js  
- C:\Users\abdal\AppData\Roaming\npm\node_modules\expo-cli\node_modules\@expo\dev-server\build\HermesBundler.js
- C:\Users\abdal\AppData\Roaming\npm\node_modules\expo-cli\node_modules\@expo\dev-server\build\MetroDevServer.js
- C:\Users\abdal\AppData\Roaming\npm\node_modules\expo-cli\node_modules\xdl\build\start\startDevServerAsync.js
- C:\Users\abdal\AppData\Roaming\npm\node_modules\expo-cli\node_modules\xdl\build\internal.js
- C:\Users\abdal\AppData\Roaming\npm\node_modules\expo-cli\node_modules\xdl\build\index.js
- C:\Users\abdal\AppData\Roaming\npm\node_modules\expo-cli\build\exp.js
- C:\Users\abdal\AppData\Roaming\npm\node_modules\expo-cli\bin\expo.js
Error: Cannot find module './lib/source-map-generator'
Require stack:
- D:\react\react projects\reacttest\first-proj\node_modules\source-map\source-map.js
- D:\react\react projects\reacttest\first-proj\node_modules\snapdragon\lib\utils.js
- D:\react\react projects\reacttest\first-proj\node_modules\snapdragon\lib\compiler.js
- D:\react\react projects\reacttest\first-proj\node_modules\snapdragon\index.js
- D:\react\react projects\reacttest\first-proj\node_modules\anymatch\node_modules\braces\lib\braces.js
- D:\react\react projects\reacttest\first-proj\node_modules\anymatch\node_modules\braces\index.js
- D:\react\react projects\reacttest\first-proj\node_modules\anymatch\node_modules\micromatch\index.js
- D:\react\react projects\reacttest\first-proj\node_modules\anymatch\index.js
- D:\react\react projects\reacttest\first-proj\node_modules\sane\src\common.js
- D:\react\react projects\reacttest\first-proj\node_modules\jest-haste-map\build\lib\WatchmanWatcher.js
- D:\react\react projects\reacttest\first-proj\node_modules\jest-haste-map\build\index.js
- D:\react\react projects\reacttest\first-proj\node_modules\metro\src\node-haste\DependencyGraph.js
- D:\react\react projects\reacttest\first-proj\node_modules\metro\src\Bundler.js
- D:\react\react projects\reacttest\first-proj\node_modules\metro\src\IncrementalBundler.js
- D:\react\react projects\reacttest\first-proj\node_modules\metro\src\index.js
- C:\Users\abdal\AppData\Roaming\npm\node_modules\expo-cli\node_modules\@expo\dev-server\build\metro\importMetroFromProject.js  
- C:\Users\abdal\AppData\Roaming\npm\node_modules\expo-cli\node_modules\@expo\dev-server\build\HermesBundler.js
- C:\Users\abdal\AppData\Roaming\npm\node_modules\expo-cli\node_modules\@expo\dev-server\build\MetroDevServer.js
- C:\Users\abdal\AppData\Roaming\npm\node_modules\expo-cli\node_modules\xdl\build\start\startDevServerAsync.js
- C:\Users\abdal\AppData\Roaming\npm\node_modules\expo-cli\node_modules\xdl\build\internal.js
- C:\Users\abdal\AppData\Roaming\npm\node_modules\expo-cli\node_modules\xdl\build\index.js
- C:\Users\abdal\AppData\Roaming\npm\node_modules\expo-cli\build\exp.js
- C:\Users\abdal\AppData\Roaming\npm\node_modules\expo-cli\bin\expo.js
    at Function.Module._resolveFilename (node:internal/modules/cjs/loader:933:15)
    at Function.Module._load (node:internal/modules/cjs/loader:778:27)
    at Module.require (node:internal/modules/cjs/loader:1005:19)
    at require (node:internal/modules/cjs/helpers:102:18)
    at Object.<anonymous> (D:\react\react projects\reacttest\first-proj\node_modules\source-map\source-map.js:6:30)
    at Module._compile (node:internal/modules/cjs/loader:1103:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1155:10)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)
    at Module.require (node:internal/modules/cjs/loader:1005:19)

J'ai besoin d'utiliser npm start je peux donc tester l'application sur mon vrai téléphone avec l'application expo. alors que faire ?

Answer 1

Vérifiez s'il y a un node_modules/ dans votre projet. Il se peut que les modules n'aient pas été installés.

Vous devez exécuter

cd first-proj
npm install

et ensuite exécuter

expo start

dans le même dossier (first-proj).

Cela devrait fonctionner après ça.