I have installed node.js on my Windows-7 PC. I am not able to create websocket connection to a remote server.
I tried to load modeule "ws" in my script :
var WebSocket = require('ws')
It gave an error :
cannot find module 'ws'
So I followed instructions over here : node.js websocket module installed but won't work in scripts
Execute cmd as Administrator (Right click cmd icon-> Run as Administrator) Then type in cmd:
c:\Node Instalation Dir\> npm install -g express
c:\Node Instalation Dir\> npm install websocket --force
Then run my script :--
D:\My Script Folder \> node myscript.js
Again same error. What could be the problem ?
cannot find module 'ws'
If you install websocket, you should require websocket, not ws:
npm install websocket
Then in REPL:
var websocket = require('websocket');
Alternatively, you can use ws module:
npm install ws
Repl/script:
var ws = require('ws');
Take a look at your node_modules directory (only the first level, the dirs right beneath it). You can require each of them by exact name.
require will actually look for a node_modules in current dir, then if not found, then the parent and again parent etc. If it doesn't find it, it will look for modules installed in global path pointed to by NODE_PATH. (And of course, native modules such as http and net.)
Try to install the package locally but not globally, i.e. without the -g option.
Have you installed the module with the -g option? I think that not every module is meant to be installed globally, instead, try installing it locally for the project you are creating (npm install), and check if the error persists. [...]
If you want to just require('something'); it is better to install it locally, otherwise, you have to require('{PREFIX}something'), where prefix is the path to where yo have installed it globally. Check out this blog post , and, as it says, generally the rule of thumb is to install things locally if you are going to use them in your app, and globally if you are going to use them from the command line.
node error cannot find module already installed.
Go to your project root directory and open the package.json file and edit
Add "type":"module";
Go to the top of your js file, delete the require and use the import statement to import 'ws' into your script.
I was also facing the same issue.
Error 1:
Just simply trying npm install ws to the same folder level where I had my server.js worked for me.
Error 2:
If you are getting the error WebSocket is not defined, then try the command npm install ws, after adding the below code. if ws doesn't work then try npm install websocket
Also, add this in your file:
const WebSocket = require('ws');
var conn = new WebSocket('ws://localhost:9090');
Related
I am learning the Automated tests by using selenium web driver + Javascript and node.js.
Everything is working fine when I ran that script.js from the Visual Studio code terminal(by using node main.js)
Problem
I want to schedule this script in the scheduler which automatically tests the login functionality. But when I try to run it from the task scheduler then it gives Error: Cannot find module
Does anybody know how to get rid of this.
To fix Cannot find module errors, install the modules properly by running a npm install command in the appropriate directory as your project's app. ... or delete the node_modules folder and package-lock. json file and re-install it again using the npm install command.
rm -rf node_modules package-lock.json
I am new to react-native and have found an error that makes absolutely no sense to me.
I am trying to include a calendar library: https://github.com/wix/react-native-calendars
I have included the dependency for that library in my package.json file and run npm install
The project was running fine and as expected. I have simply added one line of code to the project:
import { Calendar, CalendarList, Agenda } from 'react-native-calendars';
Nothing else. However now I am getting a red error message when the app loads on device and this is what my console is saying:
error: bundling failed: Error: While trying to resolve module xdate
from file
/Users/Alex/Documents/workspace/mobile/node_modules/react-native-calendars/src/index.js,
the package
/Users/Alex/Documents/workspace/mobile/node_modules/xdate/package.json
was successfully found. However, this package itself specifies a
main module field that could not be resolved
(/Users/Alex/Documents/workspace/mobile/node_modules/xdate/src/xdate.js.
Indeed, none of these files exist:
*
/Users/Alex/Documents/workspace/mobile/node_modules/xdate/src/xdate.js(.native||.ios.js|.native.js|.js|.ios.json|.native.json|.json)
*
/Users/Alex/Documents/workspace/mobile/node_modules/xdate/src/xdate.js/index(.native||.ios.js|.native.js|.js|.ios.json|.native.json|.json)
at ResolutionRequest.resolveDependency (/Users/Alex/Documents/workspace/mobile/node_modules/metro/src/node-haste/DependencyGraph/ResolutionRequest.js:103:15)
at DependencyGraph.resolveDependency (/Users/Alex/Documents/workspace/mobile/node_modules/metro/src/node-haste/DependencyGraph.js:272:4579)
at dependencies.map.relativePath (/Users/Alex/Documents/workspace/mobile/node_modules/metro/src/DeltaBundler/traverseDependencies.js:376:19)
at Array.map ()
at resolveDependencies (/Users/Alex/Documents/workspace/mobile/node_modules/metro/src/DeltaBundler/traverseDependencies.js:374:16)
at /Users/Alex/Documents/workspace/mobile/node_modules/metro/src/DeltaBundler/traverseDependencies.js:212:33
at Generator.next ()
at step (/Users/Alex/Documents/workspace/mobile/node_modules/metro/src/DeltaBundler/traverseDependencies.js:297:313)
at /Users/Alex/Documents/workspace/mobile/node_modules/metro/src/DeltaBundler/traverseDependencies.js:297:473
at
However I have checked in the directory and in fact /Users/Alex/Documents/workspace/mobile/node_modules/xdate/src/xdate.js does exist. However I do not see any of this part: (.native||.ios.js|.native.js|.js|.ios.json|.native.json|.json)`
As to how /Users/Alex/Documents/workspace/mobile/node_modules/xdate/src/xdate.js/index can exist, that doesn't make sense because xdate.js is not a directory.
Any help?
It Usually happens if you try to install a module while your packager is open.
Try to delete node_modules folder and close the packager.
Then reinstall everything by npm install in your project directory.
First close your JavaScript bundler (Metro bundler in my case) and restart the application. This will create fresh dependency graph. This should solve the issue.
Just restart the bundler - no need to delete the Node Modules folder
I came across this issue when adding and using react-native-elements when using VS Code and Android Studio emulator on Linux Mint
In VS Code I had a terminal running Expo with Metro Bundler via 'npm start' command. After installing the react-native-elements in the folder (using 'npm install --save react-native-elements') and adding the import into the .js file I got the "However, this package itself specifies a main module field that could not be resolved" error.
In my case, this just involved a ^C in the terminal session to stop the Metro bundler and then running 'npm start' again. There was no need to delete the node modules folder at all.
If you're still getting the error even after deleting the ./node_modules folder and running npm install again, try doing the install with the --update-binary flag, i.e npm install --update-binary. This should clear out and rebuild any previously built packages on your machine.
Please don't delete the node modules folder.
The bundler has least to deal with node modules folder.
Instead close all the terminals. If using VS-code close that also.
Close all the local host server ports and if possible restart the system.
This might solve the issue.
If anyone have same issue, and remove node_module not working. Then you can try remove all node_module, package lock and using yarn to install node_module instead npm. Hope this help
None of the solutions above helped me except for restarting my MacBook. Wasted 30 minutes trying to fix this issue as I couldn't believe restarting my computer could be a solution.
I am trying to setting my MEAN application on bitnami server. While installing dependencies I am facing below error. I followed all the instructions given in the error but unable to solve it.
No package 'cairo' found during installing nmp install canvas.
The error i am facing is following
Package cairo was not found in the pkg-config search path.
Perhaps you should add the directory containing `cairo.pc'
to the PKG_CONFIG_PATH environment variable
No package 'cairo' found
I have set the environment variable on bitnami server by taking reference from bitnami documentation but still getting same error.
But it is working fine in local system with same environment.
Please help me.
Thanks in advance.
You need install cairo on ec2 instance before install node-canvas.
On newer versions of Amazon Linux (2015.03 and above) the following
command is sufficient to install node-canvas:
$ sudo yum install cairo-devel libjpeg-turbo-devel giflib-devel -y
https://github.com/Automattic/node-canvas/wiki/Installation---Amazon-Linux-AMI-(EC2)
or, if Ubuntu and other Debian based systems:
$ sudo apt-get update
$ sudo apt-get install libcairo2-dev libjpeg8-dev libpango1.0-dev libgif-dev build-essential g++
https://github.com/Automattic/node-canvas/wiki/Installation---Ubuntu-and-other-Debian-based-systems
If error with PKG_CONFIG_PATH will be repeated, you need to find where the cairo.pc:
$ dpkg-query -S cairo.pc
libcairo2-dev: /usr/lib/x86_64-linux-gnu/pkgconfig/cairo.pc
libpango1.0-dev: /usr/lib/x86_64-linux-gnu/pkgconfig/pangocairo.pc
and manually add this path to PKG_CONFIG_PATH in file /opt/bitnami/scripts/build-setenv.sh
maybe you also need to add the path to xproto.pc:
$ dpkg-query -S xproto.pc
x11proto-core-dev: /usr/share/pkgconfig/xproto.pc
and add -I/opt/bitnami/common/include/freetype2 to CXXFLAGS
As a result, build-env.sh looks like this: https://gist.github.com/bouriate/81ac44f63c0107f2c74f
P.S. You need logout/login from instance for the changes to take effect.
I am attempting to install the node.js module 'javascripting' (source code can be found: https://github.com/sethvincent/javascripting) and have been unable to install it as a global variable to run through the terminal.
After installing node.js I attempted to install javascripting with the line: npm install --global javascripting
While it is my understand that this should work, it only downloads the module but does not set it as a global variable to be run in terminal.
The error I receive when attempting to run it as a global variable is "/usr/bin/env: node: No such file or directory".
After receiving this error I attempted to move the module to /usr/bin/env from the directory it installed in (usr/local/lib/node_modules/javascripting). Unfortunately, I was not able to move the files because /usr/bin/env is not a directory, rather it seems to be some sort of executable java file (usr/bin is a directory).
I am a bit lost and would love some advice on either how to install the module as a working global variable or whether there is another way to run the module without installing it as a global variable.
This will happen if the node.js binary (node) is not installed in the $PATH anywhere.
if you run env node by itself, you will get the same error. It looks like this may be an Ubuntu bug: https://github.com/joyent/node/issues/3911
Try sudo ln -s /usr/bin/nodejs /usr/bin/node - that will symlink the node.js binary from the name Ubuntu gave it to the name it's supposed to have.
EDIT:
As mscdex pointed out in a comment (and as mentioned at the end of the bug I linked), there's a legacy package you can install that should create this symlink.
sudo apt-get install nodejs-legacy
The bug I linked above indicates that there are probably other problems with Ubuntu / Debian's default node.js package, and recommends you install your own either from the PPA mentioned there or from source.
You'll probably need to follow the advice in NPM modules won't install globally without sudo as well.
I use "npm install -g express" on windows console.but when I try to "node app.js", it shows me the error"can not find module express",I had set the environment variable"NODE_PATH",but nothing happen ,I need your help,Thank you!
Globally installed modules aren't accessible without full path. You need to install express in your project directory or it parents. Check out documentation about module loading.
npm allows two options on how to install a module: locally and globally.
A global installation (done using npm install -g xyz) is for providing some tooling system-wide. Related to express this provides the global express bootstrapper that you can use to create an initial frame for your app by simply typing: express .. If you need help on what you can do with this command, check out its help parameter: express --help.
In contrast, a local installation of a module provides this module for a specific app. A local installation is always made to an app's node_modules folder. When you try to require a module, Node.js searches the this folder for the requested module.
Hence, it is perfectly fine to have express installed multiple times: Once globally for the bootstrapper, multiple times locally (once per app).
So, to cut a long story short: To make your app run, install express locally using npm install express and that's it :-).