Debug a react-native application using nuclide - react-native

Is there any good document/video that talks about how to debug a react-native application using Nuclide.
Am a newbie. Its my first time app development and first time with React.
I did create the project using react-native init. I don't think i found a BUCK file for me to run and debug my app. I also don't see to get how to view the errors in my JS file. I have to run the simulator to see. I run it using react-native run-ios.
I tried Nuclide->React Native->Start Debugging. Not sure what this is supposed to do.
Sorry if these questions sound silly.

According to this instruction you should:
From the command Palette (Cmd-Shift-P) choose "Nuclide React Native: Start Packager" to start the React Native Server.
Ensure that you are in the root directory of the React Native project, then run the application from the command-line: "$ react-native run-ios" (or choose other existing simulator, for example react-native run-ios --simulator="iPhone4s").
After starting the server, you can prime the React Native Debugger for when the application begins running. From the command Palette (Cmd-Shift-P), launch "Nuclide React Native: Start Debugging".
From the Simulator press Cmd-D (Ctrl-D on Linux). This will bring up the debug options for your application. Select "Debug JS Remotely.
...After you enable debugging from the simulated application, Nuclide will attach to that debugging process automatically, since we primed the Debugger above.

Debug JS in Nuclide is now an option in the dev menu added in React Native version 0.52 December 2017 release.
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Related

Failed to intall the app in react native, how can I fix this?

I was trying execute myapp to android but an error occurred.
To clarify what happened, first time I install nodejs and Android Studio.
Later I used the following commands:
npx react-native init 'app'
cd app
npx react-native run-android
Its my fisrt time messing with react native, I was following this page:
https://learn.microsoft.com/pt-br/windows/dev-environment/javascript/react-native-for-android
And the error is:
The error
I want coding in real time for android app.
How can I fix this?
Looks like the terminal output gives you several steps to do/check.
Make sure you have properly set up your android environment. Use this link to do so. You can use Expo-Cli or React-Native-Cli.
SDK location not found. This could be an off-shoot error of not properly doing step 1. However, to cover all of your bases, ensure you have properly set up your Android Emulator. This doc is a great walkthrough.
Once your Android studio and AVD Manager is properly set up, and your development environment is properly set, you should have no issues!
Please let me know if doing the above to steps did or did not solve your errors.
If you follow the steps, https://reactnative.dev/docs/environment-setup and https://developer.android.com/studio/run/emulator there will be no problem.
As a React Native fan on Windows 10, I'd like to mention just few points you need to check.
First, please check following user variables in Environment Variables ( You can see it from System Properties).
adb="C:\Users{username}\AppData\Local\Android\Sdk\platform-tools"
ANDROID_HOME="C:\Users{username}\AppData\Local\Android\Sdk"
JAVA_HOME="C:\Program Files\OpenJDK\openjdk-11.0.15_10"
Path: check if contains {ANDROID_HOME}\platform-tools
Eg:"C:\Users{username}\AppData\Local\Android\Sdk\platform-tools"
Second, if you are using Android Sdk emulator, please make sure that it configured correctly in emulator list in Android Studio.
For an instance, I created a android emulator using android sdk-29 and you can check the followings.
Third, I recommend you, deploy first app on emulator in Android Studio.
Because we need to download gradle zip file and others, it's essential to run your first android app in Android Studio.
When you confirmed your first android app(Deploy empty project app is also okay), you can run your React Native App by Expo-cli or react-native-cli.

React Native Expo app - unable to open app in iOS emulator

I want to run my React Native app in the iOS emulator. Here is what I done so far:
I installed XCode, along with its command line tools, and can bring up the emulator without issue.
I created an empty React Native app using the Expo CLI, per the instructions here. https://facebook.github.io/react-native/docs/getting-started. I am running on Node v10.0.0 on a Mac.
Afterwards I install all the necessary dependencies.
I then run "sudo npm run ios". This fires up the Metro Bundler as well as the iOS simulator. The Simulator loads up after about 5 minutes of waiting, but my app does not start up.
What am I missing here?
I should note that I prefer to stick with Expo, so I'd prefer not to have to eject.

Expo React-Native App doesn't work when run as a standalone APK

My Expo-based React Native App works without a problem when run in the Expo tool but gave the following errors when built as an APK to be installed and run standalone.
A series of white screens keep flipping before the blue screen comes up.
Here are my App.JSON and Package.JSON files
Package.json
App.json
And here are the screen capturing the error message.
Actually there are two ways to create a React Native application
create-react-native-app (CRNA)
react-native init
As you stated in comment section, You created your project using CRNA
CRNA will gave you some form of solid project structure, which is really useful for beginners to get started with react native, you code the app with pure javascript and the app will work inside Expo.
Now if you want to take build and run as a standalone apk for android,
There are two methods
You can run command: exp publish:android
You can eject your app from expo
Dont use exp publish for standalone apks,
You can use second method:
To eject your app:
First if you dont use any expo apis inside your apps, it is very easy to eject and build as a stand alone apk.
just do yarn eject
This will gave you some instructions and follow that.
After that your CRNA project structure will be converted into react-native init project structure, now you will be able to see "Android" and "iOS" folders inside your application
To take build Run: connect your phone with USB debugging ON and react-native run android.
That's all.
Solved my own problem. The 'eth-lightwallet' library works perfectly within the Expo development tool but when I build into an APK, it just made the white screen turns up with no meaningful error messages.
The solution is to replace it with a pure web3js implementation.
This may be useful if you are developing a mobile app for Ethereum.

console.log doesn't work with react-native

I'm starting with react-native and I'm getting this problem: I can't log to bundler metro server.
If I create my application using create-react-native-app, I can do 'console.log' and value are logged to metro bundler (running on port 8081).
But if I create my application with react-native init <project>, this doesn't work. To make console.log work, I need to open Chrome DevTools and set remote debug in application.
So my question is: is there any way to make native code to log in bundler console with console.log? I don't want to work with 'create-react-native-app' because it uses Expo and 'realm' database doesn't support expo.
I've tried with react-native 0.55.4 and 0.56, both in windows and linux.
You can also see the console.log() outputs using these commands:
$ react-native log-android
$ react-native log-ios
Note: It also works to debug native errors, for example when you have a blank screen and metro bundler doesn't show errors neither.
For more information you can check this out
Don't know if I correctly understand your question (because of my english), but you can try this:
Run adb logcat *:S ReactNative:V ReactNativeJS:V in a terminal to see
your Android app's logs.
Taken from Using adb logcat for React Native Debugging
You can download React Native Debugger and Open your JS Debugger in development menu. You can see everything into RN Debugger.
I discovered that console.log are omitted from console log if your disable remote debug from the debug menu
On Mac. While on ios simulator Clicked on
Command-d->Stop Debugging
.This made logging work for me.

React Native stuck on Loading dependency graph, done and when go to localhost:8081, I see React Native packager is running

Env:
Mac OS X
nodejs 8.9.1
Xcode installed
using boilerplate generated by https://github.com/react-community/create-react-native-app
Symptom:
React Native stuck on Loading dependency graph, done and when go to localhost:8081, I see React Native packager is running.
Also the command line after I did npm start what I got is Loading dependency graph, done. and just stay there, even after I waited for almost 5min.
Actually I found the answer myself.
There is actually nothing wrong. I forgot to start the React Native in the simulator! lol Silly right?
So basically let say if you want to start the iOS simulator in a MacOS, you can just do react-native run-ios --simulator="iPhone 5s" in your project root. Then boom! your project started!
Note that React Native can't really run in the browser, it has to be running inside a phone simulator either iOS or Android.
See official doc for more https://facebook.github.io/react-native/docs/running-on-simulator-ios.html
Have fun!