ReferenceError: Can't find variable: W4r in React Native - react-native

After adding the new files from a different folder I got this error:
ReferenceError: Can't find variable: W4r
ERROR Invariant Violation: "main" has not been registered. This can happen if:
Metro (the local dev server) is running from the wrong folder. Check if Metro is running, stop it, and restart it in the current project.
A module failed to load due to an error and AppRegistry.registerComponent wasn't called.
I did not find the "W4r" in anywhere in my code

Remove node_modules folder
Install dependencies (npm i)
Close android emulator & close metro window
cd android && gradlew clean
npx react-native start --reset-cache
After "Metro" opens, close it
npm run android
I try this when my env no respond, hope its help you.

Related

Error initialising the React Native awsomeProject via the CLI

I am trying to get the basic react native app from https://reactnative.dev/docs/environment-setup running via the CLI, but I am getting errors. I have node, python2 and jdk8 installed. I have all the Android Studio components installed as far as I can tell. I've added the environment variables.
When I run npx react-native init AwesomeProject to initialise the project, I get green ticks next to Downloading Template, Copying Template and Processing Template, but a red cross next to Installing dependencies. The error below that states Error: command failed: npm install. And further down after some warnings it states npm ERR! Unexpected end of JSON input while parsing near '...anbul":"0.4.5","mocha'
And in the initialised app folder there are no node modules.
Any idea how I get this working?
Hi the solution for this is to clear your cache :)
Please run the following command and retry:
npm cache clean --force

Getting Building iOS bundle error when trying to build an android app - expo -react-native

I was able to build app using expo build:android previously. However, after upgrading to latest expo version I get following error:
connect ECONNREFUSED 127.0.0.1:19001
Set EXPO_DEBUG=true in your env to view the stack trace.
I also see the following lines in the log:
Publishing to channel 'default'...
Building iOS bundle
I don't added ios to my app.json, I only need to build an android apk. To do that I use expo build:android -t app-bundle
I also removed package-lock.json and node_modules and run npm install, but I get the same error.
I run expo start on another cmd and then run expo build:android -t app-bundle still get same error
Also when I clear expo cache, see the following log:
Restarting Metro Bundler...
Starting Metro Bundler on port 19001.
Couldn't adb reverse: adb.exe: error: Invalid source port: 'undefined'
I had faced same issue myself and found the solution. Expo is looking for localhost:19001 which is not running. Just follow following steps and it should work as expected:
Run expo start no terminal and once it opens up the
browser where you will find this line written Starting Metro
Bundler on port 19001.
Now open another terminal instance and run expo build:android.

bundling failed: Error: ENOENT: no such file or directory, scandir React Native

I have no error in my project. But the build not successfully load. see the below image. for more details for error. I am using the below command to run the build react-native run-android but the npm failed to create the build. this image directory exists and I give the correct path for images. Thanks in advance.
-root
--assets
---images
---- All Images here.
../../assets/images/sky-img.jpg use this in code.
Just closing and re-opening the cmd terminal or whatever you are using to run the metro bundler worked for me.
Just reset the cache of your Metro Bundler with:
npm start -- --reset-cache
This is happening because the bundler needs to refresh it's existing bundles and the path you previously set.
Make sure you run the command from the root directory and not from android directory.
android> cd..
project> npx react-native run-android --variant=release

error: bundling failed: ReferenceError: Module not registered in graph

i am a newbe in react native
i don't know what is going on with my apps
the node said "error: bundling failed: ReferenceError: Module not registered in graph"
please helpenter image description here
This error usually occurs when you install a new module (while packager is open).
Firstly you can try close your packager and run react-native run-ios. If this approach does not help, you can try delete node modules directory and npm install again. But i believe first approach will work.

npm server fails to start on brand new react native project

I just started on a fresh dev environment with Xcode 7.2.1, and installed react-native (0.20.0). I initialized a test project to see if it would run, and I got the following error:
~/dev/TestProj/node_modules/react-native/packager ~
packager.sh: line 11: node: command not found
The iOS Simulator screen says:
Could not connect to development server.
Ensure the following:
- Node server is running and available on the same network - run 'npm start' from react-native root
- Node server URL is correctly set in AppDelegate
URL: http://localhost:8081/index.ios.bundle?platform=ios&dev=true
Sure enough, if I go into the project folder in a terminal window and run 'npm start' from there, the packager starts and everything works. In my experience the packager should run by itself though when you run a project with React Native. Am I doing something wrong here or is there an issue? Never had this happen with previous versions of RN.
I moved on to trying to get my old project working, and while trying to use npm to add new packages, I added the following to my ~/.profile. I'm guessing this fixed it:
export NPM_DIR="$HOME/.npm" [ -s "$NPM_DIR/npm.sh" ] && . "$NPM_DIR/npm.sh"