cant start react native project using npm/expo start

Question

following react-native docs to make an android app after using

npm install -g expo-cli

command and in the same project file using

expo init first-proj

cd first-proj

everything is good until I do npm start it's going to give me an error

> 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?

and so I downloaded npm by using npm install but now it's giving another problem. when I type npm start it shows this in the terminal of vs code

> 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'
  ]
}

And if I do expo start instead it gives

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)

I need to use npm start so I can test the app on my real phone with the expo app. so what to do?

score -2 · Answer 1 · answered Feb 12 '22 at 15:09

-2

Check to see if there is a node_modules/ folder in your project. The modules might not have been installed.

You need to run

cd first-proj
npm install

and then run

expo start

in the same folder (first-proj).

It should work after this.

answered Feb 12 '22 at 15:09

Abhishek Sah

384
5
12

1

you are not "installing" npm, you should already have it installed when you downloaded and installed node.js (did you do that), and then when you go into the project directory and run `npm install` you are installing the dependencies mentioned in your package.json file. – Abhishek Sah Feb 12 '22 at 17:15

cant start react native project using npm/expo start

1 Answers1