brennanMKE

fileprivate func directoryExistsAtPath(_ path: String) -> Bool {
    var isDirectory = ObjCBool(true)
    let exists = FileManager.default.fileExists(atPath: path, isDirectory: &isDirectory)
    return exists && isDirectory.boolValue
}

jarretmoses

RN < 0.50 - watchman watch-del-all && rm -rf $TMPDIR/react-* && rm -rf node_modules/ && npm cache clean && npm install && npm start -- --reset-cache
RN >= 0.50 -  watchman watch-del-all && rm -rf $TMPDIR/react-native-packager-cache-* && rm -rf $TMPDIR/metro-bundler-cache-* && rm -rf node_modules/ && npm cache clean && npm install && npm start -- --reset-cache
RN >= 0.63 - watchman watch-del-all && rm -rf node_modules && npm install && rm -rf /tmp/metro-* && npm run start --reset-cache

npm >= 5 - watchman watch-del-all && rm -rf $TMPDIR/react-* && rm -rf node_modules/ && npm cache verify && npm install && npm start -- --reset-cache

Windows - del %appdata%\Temp\react-native-* & cd android & gradlew clean & cd .. & del node_modules/ & npm cache clean --force & npm install & npm start -- --reset-cache