React Native在新的初始化应用程序上找不到模块./index

Question

I issued react-native init MyApp and react-native run-android

Metro server started but when phone request data from it, it crashed giving

Error: Unable to resolve module `./index` from `\node_modules\react-native\scripts/.`: The module `./index` could not be found from `\node_modules\react-native\scripts/.`. Indeed, none of these files exist:

Machine has newly installed node, npm and it's modules so no cache issues, but then what is preventing react native to give even its first glimpse?

Answer 1

Solution Github Ref: #23908 (comment)

Metro server instance is started by runAndroid.js from @react-native-community module if asked for react-native run-android

Problem is with Working Directory , Metro instance is launched with wrong working directory and no projectRoot is passed in launchPackager.bat

Threre are two fixes for this issue, apply only one of the below

Update node_modules\\react-native\\scripts\\launchPackager.bat file .

@echo off
title Metro Bundler
call .packager.bat

:: delete this line
node "%~dp0..\cli.js" start 

:: Add this line
node "%~dp0..\cli.js" start --projectRoot ../../../ 

pause
exit

We are giving project root path to Metro instance here via projectRoot argument,

Or in \\node_modules\\@react-native-community\\cli\\build\\commands\\runAndroid\\runAndroid.js edit this ,

const procConfig = {

    // delete this line    
    cwd: scriptsDir

    // add this line
    cwd: process.cwd()

};

We are launching Metro Server with working directory to our project root

For more info see startServerInNewWindow() function in \\node_modules\\@react-native-community\\cli\\build\\commands\\runAndroid\\ranAndroid.js , it is passing react-native directory rather than project root in third argument of spawn() .

It worked, hope this will help you as well