i just started a project and im trying to start the but it already has this error showing:
error: node_modules\react-native\Libraries\Image\ImageAnalyticsTagContext.js: Property body[6] of BlockStatement expected node to be of a type ["Statement"] but instead got "AssignmentExpression"
this is a known issue caused by a bug in a newly released version of babel. it will impact all new react-native and expo apps. you can resolve it with yarn resolutions in a new project:
--- a/package.json
+++ b/package.json
## -25,5 +25,8 ##
},
"jest": {
"preset": "react-native"
+ },
+ "resolutions": {
+ "#babel/plugin-transform-react-display-name": "7.14.5"
}
}
After insert resulutions key on the package.json, run yarn install
Credits: https://github.com/brentvatne
Issue Link: https://github.com/facebook/react-native/issues/31961
Run this command:
npm install --save-dev #babel/plugin-transform-react-display-name
The problem is due to a babel update that affected the RN project. copy #babel from some other project and paste in node_modules or Download the #babel folder from here and replace the existing folder in the node_modules.#Babel Download
And run
npm start --reset-cache
I have been trying to include a React native library (Local Library) to the React Native app.
So I installed it using
npm install library-path
Then I run
npm link libraryname
I can see the package in the node_modules of the mainProject. Also, in package.json, I can see the dependencies:
"dependencies": {
"react": "16.13.1",
"react-native": "0.63.2",
"react-native-first-library": "file:../react-native-first-library",
"react-native-toast-message": "^1.3.3",
"react-native-webview": "^10.8.3"
},
react-native-first-library is my react module.
I have done
Clear watchman watches: watchman watch-del-all
Delete node_modules: rm -rf node_modules and run yarn install
Reset Metro's cache: yarn start --reset-cache
Remove the cache: rm -rf /tmp/metro-*
But still, it is not working. I don't know why these things are so complex.
A lot of confused answers here. when you install a local package via npm install 'path/to/local/package', or in your package.json with 'file://path/to/local/package', npm links to the local package without copying. metro bundler does not know how to resolve these locally linked packages properly. you can update metro bundler config to do this.
example from my metro.config.js:
// paths to local packages
const localPackagePaths = [
'/Users/alexchoi/package-name',
]
module.exports = {
transformer: {
getTransformOptions: async () => ({
transform: {
experimentalImportSupport: false,
inlineRequires: true,
},
}),
},
resolver: {
nodeModulesPaths: [...localPackagePaths], // update to resolver
},
watchFolders: [...localPackagePaths], // update to watch
};
and then metro bundler will know how to resolve these locally linked packages.
make sure you restart metro bundler npx react-native start
I had to integrate a custom library once. I just created a folder at root level customLibs and I put the folder of my library into. Then in the package.json I specified "myLib": "file:./customLibs/myLib"
I'm not sure but in your package.json the path should not be file:../react-native-first-library with two dots but surely with one dot.
And at the end just yarn or npm i
I noticed react-native-webview was not found in node_modules/, so I did npm install react-native-webview. And it was fixed.
Try this code:
npx react-native link react-native-webview
just do one thing
1). copy the local library folder and paste it into the node_modules of the react native project..
example =>
i have a library say react-native-test
=> after installing it in a react native project I can see that package.json file has added a dependency like "react-native-test": "file:../react-native-test",
but i got an error as soon as I ran the project displaying unable to resolve module
=> just copy the react-native-test folder and paste it into the react native project's node_modules folder and do npm install again
I was compiling perfect way for adding eslint-flow-prettier in all types of react native projects.
I have some question about using eslint in Expo project.
Does exp init also install eslint?
If not, I have tried using following command for installing eslint
1)yarn add --dev eslint eslint-config-airbnb eslint-plugin-import eslint-plugin-react eslint-plugin-jsx-a11y babel-eslint
2)yarn eslint --init
Is this the correct way to put eslint in expo project?
In the second step above it asked to Select 'Use a popular style guide', I selected Airbnb, after that it removed multiple packages and project is not running(obvious reason for error: missing libraries).So why this is happening?Should I have selected config other than Airbnb?(only 3 options for eslint config: Google, Airbnb, Standard)
Also I did use YARN for expo project because NPM was giving more complication, as it was removing 500+ packages during step1 above, which resulted in many of the libraries going missing from project, I tried npm install to install all packages but still had problems. So went with YARN.
For now I want to somehow include eslint in the Expo project.
Thanks in advance.
UPDATE 26th March 16:25 IST:
1)Here is the info after installing eslint using: npm install --save-dev eslint-config-airbnb babel-eslint (npm version 5.8.0)
install eslint-config-airbnb and babel-eslint as dev dependencies.
create a file in your root named .eslintrc and add this inside this file
{
"extends": "airbnb",
"parser": "babel-eslint",
"rules": {
}
}
install Eslint extension in your editor. this is the extension for vscode(you can enable eslint if you are using Webstorm)
This problem got solved by deleting node_modules folder in project directory and did npm intsall.
So, during any npm install <package> if it removes some other previously installed packages, only way for now is to delete whole node_module folder and perform npm install. This worked for me, when this problem occurred while creating react-native app with native code support(https://facebook.github.io/react-native/docs/getting-started.html).
I am developing a React Native app. My code is error free, but it is facing build problems. I get an error in the Metro Bundler when I execute the command react-native run-android. The error says:
UnhandledPromiseRejectionWarning: Failed to start watch mode.
I also tried adding Watchman to node_modules using the command $yarn add watchman.
I get a prompt that it is deprecated.
How should I solve the error?
My package.json contains the following:
"dependencies": {
"expo": "^25.0.0",
"native-base": "^2.3.7",
"react": "16.2.0",
"react-native": "0.52.0",
"react-native-vector-icons": "^4.5.0",
"react-navigation": "^1.0.0-beta.27",
"watchman": "^1.0.0"
}
"devDependencies": {
"babel-jest": "22.1.0",
"babel-preset-react-native": "4.0.0",
"jest": "22.1.3",
"react-test-renderer": "16.2.0"
}
To have watchman in windows do the following:
(1)Download watchman zip file from the link here
(2) Unzip the folder
(3) Place the watchman.exe file in the folder that is registered in the PATH (environment variable) (Eg: Place the watchman.exe file in C:/ProgramFiles/ and make sure the PATH = 'C:/ProgramFiles')
Done! You would never face this error again!
I have also faced the same issue.Then I have
Deleted the node modules and installed them again by using npm install.
Then clean gradle by '.\gradlew'
Then run the app by 'npx react-native run-android'.
The above steps helped me to resolve the error.
You have to install watchman using brew:
brew install watchman
in windows npm install watchman
I tried the following:
Restarting my system
Deleting npm/yarn cache.
Most of the times the above methods worked but not always. So, here's one-time permanent solution (for Windows)
Download the Watchman v2021.01.11
Unzip, Rename the folder "Watchman" and paste the C:/Program Files.
Open the folder and copy the location of bin folder (would be C:/Program Files/Watchman/bin)
Go to Environment variables, search of PATH variable and append the copied location of bin
same issue I got on metro Android
I tried the following Steps:-
1.npx react-native start --reset-cache
2.cd android && ./gradlew clean && cd..
3.npx react-native run-android
In mac, I used
watchman watch-del-all
on Terminal
then I re-run the XCode. It's working
Failed to start Watchman watch mode (Windows)
I tried a lot to fixed the issue and at last, I restart my windows now it's working.
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Getting the following message when I init a new project and then launch the Xcode emulator:
React-Native Version Mismatch
Javascript Version 0.50.1
Native version: 0.50.0
Make sure you have rebuilt the native code. ...
Does anyone know what is going on here and can help me?
This is what I've done with it:
Close all terminals and run build again.
You may forget to close nodejs terminal from another project, and they happen to have installed different react version.
So the code fetches from nodejs server conflicts with the native one.
In case you created your react-native app using create-react-native-app. You should have a app.json (expo). and a package.json file, check if the expo versions match and change accordingly. For example in my case the problem was that in the app.json file I had a 25.0.0 version for the expo sdkVersion attribute, I change that to 23.0.0 and everything worked.
package.json:
"dependencies": {
"expo": "^23.0.4",
"react": "16.0.0",
"react-native": "^0.50.4"
}
app.json:
{
"expo": {
"sdkVersion": "23.0.0" // before was 25.0.0
}
}
Just go to your android/app/build.gradle and then add to the dependencies section:
dependencies{
compile ("com.facebook.react:react-native:0.50.3") { force = true }
}
/// the react native version can be found in package.json
For Android developers who couldn't get it fixed by just closing and rebuilding, Manually uninstall the app on the emulator/device.
just force react native version in your android's app level gradle file, in the dependencies section.
compile ("com.facebook.react:react-native:0.52.0") { force = true }
worked for me
If you're running your React Native app through Expo, upgrading React Native is liable to cause this error (as noted at https://github.com/expo/expo/issues/923).
If that's your scenario, your options are:
Bump Expo (which is listed in your package.json) to a version that is compatible with your React Native version (if one exists, which may not be the case - judging by the linked issue, I figure that Expo support trails React Native releases).
Discard your changes, delete and reinstall your Node modules, Eject from Expo, and then (after checking that you can still run your app post-ejection) try your upgrade again.
I've never seen this error before, but whenever I can't get Xcode and React-Native to play well together, I do a couple of things. Check what version of Xcode I'm working with. If it needs to be updated, I update it. Then clearing watchman and the cache are the second place I go. I don't use the reset cache command. It always says that I need to verify the cache, so I skip that (you can do it though, I just get confused). I use rm -rf $TMPDIR/react-* to get rid of any cached builds. If that doesn't work, I try to build the app in Xcode, then work my way from there, to build it with react-native run-ios. With this error message, it seems you might start by trying to build it with Xcode. Hope that helps...let me know your progress with it. Good luck! (Also, you could update to RN 0.51 as another attempt to get your versions synced.)
I had this problem for the longest time and none of the above solutions helped. I was in the middle of upgrading react native in a create-react-native-app project until I found out that not all versions of Expo support the latest React Native.
Found this page linked in the documentation that shows which version combinations of React Native, React, and Expo are officially supported:
Source: https://github.com/react-community/create-react-native-app/blob/master/VERSIONS.md
Editing the app.json and package.json files to match the corresponding versions and running npm install got everything working again.
I am using a physical device, in my case this solved the problem:
Uninstall the app
lsof -i :8081
kill -9 PID
Rebuild the app (react-native run-android or react-native run-ios)
In your build.gradle file add the following
implementation ("com.facebook.react:react-native:0.51.0") {
force = true;
}
replace 0.51.0 with the version in your package.json
Try installing the dependencies again. That worked for me-
1.) yarn/npm install
2.) yarn/npm start --reset-cache
For me it was due to react-native version in dependency section of package.json file. It was:
"dependencies": {
"expo": "^27.0.1",
"react": "16.3.1",
"react-native": "~0.55.0"
}
I chaged it to:
"dependencies": {
"expo": "^27.0.1",
"react": "16.3.1",
"react-native": "0.52.0"
}
Now it works fine.
In my case installing a new virtual device helped. Now I am using 1 device per app.
It happens sometimes when you try to run without closing the node server, in which the previous app was running, so try restarting React.To do so, just run the following commands:
1. To kill current processes
killall node -9
2. To Start React Native
react-native start
3. Then Run android
react-native run-android
For my case I'm facing it on iOS, and I've tried to reset and clear all cache using below command but failed too, despite many comments saying that the root cause is there is react packager running somewhere accidentally, I've restarted my mac and the problem still remained.
watchman watch-del-all && rm -rf node_modules/ && yarn cache clean && yarn install && yarn start --reset-cache
The solution is, to delete the build folder # /ios/build, then execute react-native run-ios solved it
I have tried the solutions above but adding this to AndroidManifest.xml seems to fix it.
android:usesCleartextTraffic="true"
For others with the same problem on iOS with CocoaPods:
I tried all of the solutions above, without luck. I have some packages with native dependencies in my project, and some of those needed pod modules being installed. The problem was that React was specified in my Podfile, but the React pod didn't automatically get upgraded by using react-native-git-upgrade.
The fix is to upgrade all installed pods, by running cd ios && pod install.
Expo users - make sure your app.json sdk version and package.json expo version are (may be equal) compatible to each other.
The fix we did was to make sure the ANDROID_HOME and PATH variables were set up prior to the build.
First, run the below two commands then the build the app for the device.
export ANDROID_HOME=/Users/username/MyFiles/applications/androidsdk
export PATH=$PATH:$ANDROID_HOME/tools:$ANDROID_HOME/platform-tools
This is working for me :
react-native start --reset-cache
I also had this issue using Expo and iOS Simulator. What worked for me was erasing the Simulator in Hardware > Erase All Content and Settings...
I have got the same issue while building my react native app for android and I did the following which worked for me.
The "JavaScript version 0.50.1" in the error console is the react-native version in your package.json file. Make sure it is the same version as "Native version 0.50.0" in the error console.
I have Updated the react-native version to the "Native Version 0.50.0" as prompted in the error console.
Rebuild the app react-native run-android.
Possible Fix:
Delete the package-lock.json
Run: watchman watch-del-all && rm -rf $TMPDIR/react-* && rm -rf $TMPDIR/haste-map-react-native-packager-* && rm -rf node_modules/&& npm install
If the problem persists, try to execute the project directly from the Xcode
This worked for me.
In my case (NOT using expo & Android build)
package.json
"dependencies": {
"react": "16.3.1",
"react-native": "0.55.2"
}
And app.json
{
"sdkVersion": "27"
}
resolved the issue
I was trying to build and run a React Native app from WebStorm and ran into this problem. The simple solution for me was:
watchman watch-del-all
On macOS, if watchman is not already installed, install it using Homebrew:
brew install watchman
In my case, I changed the expo version manually. I got the same issue because I forgot to update sdkVersion in app.json and babel-preset-expo in package.json
After that run: expo r -c to clear cache and start the app.
This Answer is Published in 2020,
Fix this Error in 3 steps:
First step: I changed the value of expo in package.json file to the latest supported version, according to expo documents(visit here).
Second step: I changed the value of sdkVersion in app.json file to the same value of expo in package.json.( equal number to last step).
Third step : I changed the value of react-native in package.json file to the same value of React Native Version , according to expo documents(visit here).
now your ready to go.
use npm install to install specified version of dependencies and then npm start to run the project
I got this classing when TypeScript type definitions mismatched.
E.G react-native at 0.61.5 in dependencies and #types/react-native at 0.60.0 in devDependencies.
As soon as I updated devDependencies it worked. Didn't have to restart anything.
edit your package.json for your javascript version
"react-native": "^0.50.1",
after run
npm install
For me, who is running with a monorepo, there was a hidden react-native version inside yarn.lock. It was not present in any package.json, but was never deleted.
I removed that particular react-native version from yarn.lock, and did a
yarn install
This cleaned out alot of old stuff and made sure that things was working fine.