Troubleshooting and Debugging React Native


Enable console.logs for React Native

# run this command (when the app is running) to enable React Native logging
# You only need to run this once and it'll be enabled for all future apps as well

npx react-native log-ios
npx react-native log-android

adb logs

You can start adb logging in another Terminal window

# For a steady stream of constant logging
adb logcat

# filter React related logs
adb logcat '*:S ReactNative:V ReactNativeJS:V'

Common Errors

White screen of death

Screenshot for white screen of death

You get an empty blank screen and no errors..

Chances are you ran react-native run-android first and then react-native start.

What you gotta do is close the app. Run react-native start and then in another terminal, run react-native run-android. You have to run react-native run-android in a separate terminal because you don't get the prompt back when running react-native start

Could not connect to development server 500 -OR- SHA-1 ReferenceError

Screenshot for 500 error

The development server returned response error code: 500
error: ReferenceError: SHA-1 for file node/v12.18.0/lib/node_modules/react-native/node_modules/metro/src/lib/polyfills/require.js (node/v12.18.0/lib/node_modules/react-native/node_modules/metro/src/lib/polyfills/require.js) is not computed

Turns out i had react-native insatlled globally instead of react-native-cli. If you have both react-native and react-native-cli installed, it'll be messed up..

Solution is simple

npm uninstall -g react-native
npm i -g react-native-cli

# OR

yarn global remove react-native
yarn global add react-native-cli

Or just use npx.


Please note that this site and the posts on it are, and will always be, a work in progress. If i waited for perfection, i’d never get anything done.