Develop Reference

NPM Install giving rollbackFailedOptional

After trying to use the Windows Powershell (as an admin), the command prompt (as an admin) and the bash CMD; I repeatedly get the following error after trying an npm install command:
npm install npm#latest -g
is the attempted command and...
[...] / rollbackFailedOptional: verb npm-session xxxxxxxxxxx
where the 'x's represent different letter and number combinations at each attempt, is the message. I am aware that this should be the first step in the installation of a package but it remains on this message for a long time and will not change.
I am trying to use the JavaScript React library, more specifically the 'create-react-app'. The npm install -g create-react-app command is also causing the error.
npm version: 6.5.0
npx version: 10.2.0
node version: 10.15.0
A solution would be greatly appreciated.

https://docs.npmjs.com/try-the-latest-stable-version-of-npm In this link there is the documentation for updating npm version for windows with a link to a tool developed by Microsoft to update npm (https://github.com/felixrieseberg/npm-windows-upgrade)

I found the solution:
As my device username has both my first and last names, with a space in between, npm was reaching errors because of this. So the solution was to uninstall node from the default location and reinstall it in a folder on my C:\ drive, where there were no files in the directory that have spaces in the names. I then changed the cache location into this same C:\ drive folder, and the problem was solved.
npm config set cache C:\NODEJS\npm-cache
(these folders must be created before you can set the config directory to these.)

For me, I ended up having to:
Uninstall Node.js
Remove the folder "nodejs" completely from C:\Program Files (or
wherever you decided to install node)
Reinstall Node.js
After that, I did not encounter [...] / rollbackFailedOptional: verb npm-session xxxxxxxxxxx anymore.
I'm not quite sure what the issue was but all suggestions I found on stack did not solve this problem for me. I hope this helps someone.

Check if you are connected to any other VPN or proxy setting. If so try to disable it or disconnect from it and then execute the npm command. It worked for me. In my case, I was using the organization laptop and was connected to external vpn network, so i disabled the vpn and tried the command and it worked.

In our case the hard disc of the nexus server (repository server) was just full. Maybe someone helps this. Before looking into other more complicated options.

for my case i uninstalled the reinstelled it and used powershell insted of cmd and it worked like a charm

First run these commands.
npm config rm proxy
npm config rm https-proxy
then run this.
npm config set registry https://registry.npmjs.org/
check if the internet is connected
and try to run the npm command which was giving the error.

Cannot find module '../build/Release/opencv4nodejs

I am new to OpenCV and node js, trying to learn OpenCV in node js.
I came across opencv4nodejs which I found best for learning.
I have followed all steps to install OpenCV and setting environment variables for OpenCV and done npm install opencv4nodejs also. able to run Quick start code given but when I try to run example machineLearningOCR.js from examples folder I get error Error: Cannot find module '../build/Release/opencv4nodejs'
I run command node machineLearningOCR.js from cmd but getting error mentioned above on line const cv = require('../');
How to run examples given in opencv4nodejs?

If you cloned the repository and want to use the examples directly from the examples folder then you have to npm install in the root directory first to build the module.
Optionally you can npm install opencv4nodejs in any project directory, copy the examples into that directory and replace const cv = require('../'); with const cv = require('opencv4nodejs');.
You can also directly submit an issue here: https://github.com/justadudewhohacks/opencv4nodejs/issues

I had the same problem and I did solve the issue with the following steps.
First all of. I checked the npm version, for this case I recommend you updated or pass your software resources at the next version.
NodeJs 14.16.0
NodeJs version: 14.16.0. You can verify the version with this command if you had another NodeJs version installed
node --version
Npm version: 6.4.11 You need verify if you had this version installed only you will able to validate this if you have NodeJs but if you didn't have node you can install the version I recommend you
npm --version
After you set the NodeJs and npm versions you need to verify the following things
Have visual studio 2015 or latest with the development for desktop component
Have cmake program installed
Have git bash
Have Java or the language you will to work
Have the environment variables for the above programs I mentioned
Then you can try again to install open Cv
You need to reopen another or new terminal and then you will execute this command
npm install --save openc4nodejs
And then
npm install -g openc4nodejs
After than or before don't forget to install appium I recommend you 1.19.1 version
You can verify if you have appium with opencv with open Cv doctor you can run appium-doctor and check if the Open cv component are present.
For to install appium doctor you can run this command, npm install -g appium-doctor
I hope this answers will be helpful for you
Autor: Eder Carbonero

react-native not found + mac os

I am trying to run basic react-native app in my macOS. I installed node through brew .
My node version: v6.12.0
npm version :5.5.1
Then i installed reatc-native-cli using npm. Now when i try to create a project using react-native init it says react-native command not found.
I tried all solutions but no hope. as i am new bee to this react-native guide me solve this. Thanks in advance.
I tried all post including
react-native: command not found

You should install React-Native CLI first before using "react-native init".
npm install -g react-native-cli
For more information of getting started React-Native in manual, please follow this Document
https://facebook.github.io/react-native/docs/getting-started.html
And select tab Building Projects with Native Code for manual create project without Expo

Steps to install React Native CLI in Mac OS:
Run npm install -g react-native-cli
or sudo npm install -g react-native-cli
2. Once successful, get the installed path from the output:
/Users/jeemok/.npm-packages/bin/react-native -> /Users/jeemok/.npm-packages/lib/node_modules/react-native-cli/index.js
+ react-native-cli#2.0.1
added 78 packages from 28 contributors in 12.39s
In my case, my path is /Users/jeemok/.npm-packages/bin/react-native
3. Run export PATH="/Users/jeemok/.npm-packages/bin:$PATH"
4. Now you should be able to use the command react-native
Example to init a project
react-native init TodoApp
cd TodoApp
react-native run-ios

1.install
-Xcode
-Android Studio
2.
react-native init FirstApp
if hit the below error
-bash:react-native:command not found
4.
npm list -g | head -n 1
5.
/usr/local/Cellar/node/8.1.4/lib
U will found the file "react native"
6.
open .bash_profile (if .bash_profile not exist setup .bash_profile)
add the below in .bash_profile file
export PATH=”/usr/local/Cellar/node/8.1.4/bin:$PATH”
run the command to reload .bash_profile
source .bash_profile
8.create your project
react-native init FirstApp

How I solved this issue.
Call npm list -g | head -n 1
Open .bash_profile in a code editor. It should be located at ~/.bash_profile
Paste export PATH="/usr/local/Cellar/node/10.12.0/bin:${PATH}" somewhere in it. Make sure you have the correct version in there. Also make sure PATH is wrapped in { }
Save the file.
Close your terminal and reopen. You should be good now.

How I solved this not found issue. For those who are still facing the issue, I am sharing my solution.
I have setup a fresh react native project by running the following command.
npx react-native init AwesomeProject
we don't need to install
react-native-cli
If you previously installed a global react-native-cli package, please remove it as it may cause unexpected issues.
as mentioned in the original docs.
just add npx at beginning npx react native link and it worked!

Angular: ng is not recognized as a command

C:\Users\Vivek Ghanchi>ng
'ng' is not recognized as an internal or external command,
operable program or batch file.
I have installed angular CLI but it is showing me the ng is not recognized is there any solution

Use;
Environment Tables -> System variables -> Path:
C:\Users\*'Your User'*\AppData\Roaming\npm
not
C:\Users\Administrator\AppData\Roaming\npm**\node_modules\angular-cli\bin**
Be aware that the path should point to YOUR USER work directory if You are not working on Administrator account.

You should install angular cli by enter the following command:
npm install -g #angular/cli

I solved it few days ago, after having the same problem with other global modules, by adding to:
Environment Tables -> System variables -> Path:
C:\Users\Administrator\AppData\Roaming\npm\node_modules\angular-cli\bin;C:\Program Files\MongoDB\Server\3.2\bin
Note that it must not have any spaces after ;
That turned out to be my problem.

Use this link to know about angular CLI. After installing Angular CLI you can able to see workable ng command.

I was facing the same issue, I uninstalled node js and then reinstalled it. Now if you run node --version, it will show current version of node, Its 14.16.1 in my case. Now run command npm install #angular/cli. It will install angular CLI. One can also run npm --version before angular cli installation for being sure that npm is working. Might be helpful for someone.

try ng --help to see if your command parameter is in the list, and word is correct. For example, ng -v is not support in new version, use ng v instead.

Node.js says it can't load sqlite3 module, but does anyway

I'm working with the new Node.js Tools for Visual Studio and included the sqlite3 npm module. When I call require('sqlite3') it throws the error:
Error: Cannot find module './binding\Debug\node-v11-win32-ia32\node_sqlite3.node'
Odd thing is, when I ignore the error and continue running the code, everything works fine...until the function I'm in returns; then the server crashes.
Has anyone else had this issue? I have a suspicion that it has something to do with the ./binding part, but wouldn't know where to begin in terms of finding out why.

use this:-
npm install sqlite3 --build-from-source

This is what worked for me: https://www.npmjs.com/package/sqlite3
npm install https://github.com/mapbox/node-sqlite3/tarball/master

From: https://github.com/mapbox/node-sqlite3/wiki/Building-On-Windows
Install required software:
Python 2.x: https://www.python.org/downloads/release/python-2711/
Win SDK: http://www.microsoft.com/en-us/download/details.aspx?displayLang=en&id=8279
Microsoft Visual Studio 2010+: https://www.microsoft.com/es-es/download/details.aspx?id=48217
Build:
npm install sqlite
npm install
node-gyp configure build

I got the kind of problem, my node version is v10.16.3
This globally installed sqlite3 gives error in loading by require('sqlite3')
It been solved by install a sqlite3 local to project.
$ npm install sqlite3
Note without -g option, it works for me.

It seems this is a problem with the sqlite3 npm package itself. There exists a lib\binding\Release\ folder, but not a lib\binding\Debug\ folder. I just created a copy of the Release folder, named it Debug, and all is well.

In case this above has not worked for anyone, here is what worked for me:
sudo apt install node-sqlite3
(I am using Ubuntu with Vscode as editor). It seems installing this node-sqlite3 module was the one that was recognized.

To skip searching for pre-compiled binaries, and force a build from source, use
npm install --build-from-source