I'm struggling to develop a deeper understanding of npx. So in particular the difference between running a commmand with npm and npx. I understand that npx can execute a package from a URL, just one local npm package etc.. But for example here:
npx lerna run start --scope frontend --stream
What is the difference between
npx lerna run start
and
npm lerna run start
?
NPM - Manages packages but doesn't make life easy executing any.
NPX - A tool for executing Node packages.
NPX comes bundled with NPM version 5.2+.
NPM by itself does not simply run any package. It doesn't run any package as a matter of fact. If you want to run a package using NPM, you must specify that package in your package.json file.
When executables are installed via NPM packages, NPM links to them:
1.local installs have "links" created at ./node_modules/.bin/ directory.
2.global installs have "links" created from the global bin/ directory (e.g. /usr/local/bin) on Linux or at %AppData%/npm on Windows.
Hi I need some clarification on npm materials.
What are the differences between "npm start" and "npm build"?
When do we use "run" for example, what are the differences between "npm test" and "npm run test"?
Thank you so much! I appreciate the explanation.
What you are finding is that there are some default scripts in NPM. Some of these are:
npm start
npm build
npm test
These are simply just aliases for npm run xxxx. To answer your question, npm run test and npm test are exactly the same. npm test is just a shorthand alias.
These default scripts are there to be used as kind of "universal" commands. For example: you have two different projects that have two different build processes. However, you could run npm build in both to build their respective build processes.
It depends on what you're using. In a react app npm start actually does npm run start but npm have allowed a shorthand version.
If you look in your package.json you'll see a scripts parameter that has all the things you can run using npm run [command]. You can define your own ones in there as well.
To answer your first question. The start and build commands are usually defined by webpack.
start is usually used to serve your app locally. So you can go to localhost and see it running.
build is used to compile your app into a folder, usually called dist/, into a flat html/CSS/JavaScript website so you can put the files onto a production server.
I am getting an error when trying to run npm run serve. At first I installed node.js then vue as well as vue/cli.
But when I am trying to run server as -> npm run serve at that time I'm getting error like 'vue-cli-service' is not recognized as an internal or external command.
I used below codes for installation:
npm install -g vue
npm install -g #vue/cli
can someone guide me what to do to solve this issue ?
I think you are using cmd in windows.
Try deleting the node_modules folder and after that run npm i from the cmd.
Then try running npm run serve again and see if it works this time
Install vue/cli-service globally
npm install #vue/cli-service -g
This will install global npm package.
#vue/cli-service is usully installed as global, because you do not usually copy these types of packages to every project.
If the global npm package gets corrupted, it is not stored in node_modules folder, but rather in other depending on the os. Therefore removing node_modules does not help. Locations for global node_modules folders are
%USERPROFILE%\AppData\Roaming\npm\node_modules (Win10) or
/usr/local/lib/node_modules (Linux),
check this stack overflow post on how to locate global packages.
it will depend on the package manager you are using
delete node_modules
if you are using yarn run yarn or yarn install and then yarn serve
if you are using npm run npm install and then npm run serve
In my case, the package #vue/cli-service is installed in my local node_modules environment, but not my global environment, so it cannot be used as a command. I type .\node_modules\.bin\vue-cli-service serve and it works.
As it is mentioned in terminal that node_modules is missing from your project, so you can't directly use npm run serve, first you have to do npm install then do npm run serve. It will work fine
In my case I ran below commands in GitBash and it worked fine
npm install
npm run serve
If you are using cmd in windows.
deleting the node_modules folder and after that run npm istall from
the cmd.
run npm run serve and see if it works this time
In my case, I have checked the folder of node_modules was missing. I am using Windows. So I run this in cmd.
npm install
npm run serve
Then I check it in localhost like usual.
This issue mostly happens when either #vue/cli is not installed or in most cases,
#vue/cli is already installed and you are currently working on a project and when running
yarn serve or npm run serve.
Most at times, this issue is been caused by broken dependencies.
to fix this issue, simple run
yarn install or npm install
depending on your package manager.
well after trying all the solutions above and it still haven't worked for you then you probably have a stupid space in the full directory of your Vue project like in my case. so remove that that space and it will work from then on.
Remember to set the NODE_ENV=development and run npm install again
Try changing the project path to one without spaces, it worked on windows 10
I had faced the same problem in windows. Then
first I deleted the node_module. then I run npm install.
For Windows you should modify package.json to:
"scripts": {
"serve": "vue-cli-service.cmd serve",
"build": "vue-cli-service.cmd build",
"lint": "vue-cli-service.cmd lint"
}
,
I had the same issue using windows + WSL2 (Ubuntu 20.04). Looking at the logs generated after trying to run npm i I noticed that my WSL2 environment did not have python2 installed. So to solve I ran the following commands:
sudo apt-get install python2
rm -rf node_modules
npm i
npm run serve
I faced the same in Windows. Had to run npm install again. Then it worked perfectly.
Wait, what's the difference between #vue/cli and #vue/cli-service? When you install both, they show different number of packages installed. The latter solved my issue actually but everyone keeps saying install #vue/cli.
try running npm i or npm install and then proceed to run npm i vue after previous installation done. works for me
you need use "npm install" at Command Line
Before running "npm install", try running this command first:
npm set strict-ssl false
Like you, I got the error below when I ran npm run serve from the CMD command line,
'vue-cli-service' is not recognized as an internal or external
command, operable program or batch file.
I got past this familiar error by using the following command to add the npm folder to the PATH that CMD searches for executables:
path=%path%;C:\Users\<USERNAME>\AppData\Roaming\npm
where <USERNAME> is your Windows user profile directory name. Only then was I able to run the following commands successfully:
npm install
npm run serve
What solved the issue for me was renaming the directory. I had used the symbol "&" on the folder name and it seems to break things, so changing it to "and" fixed the issue.
This will probably be an incredibly niche thing, but if I help even 1 person it's fine by me.
I have a project, I can run it well on Linux, but i have the same issue on windows, I solve it this way (I hope in your case it works too):
Delete the node_modules
Install it again with npm i
If I open the integrated terminal and run npm -v it works.
But, if I running it directly from NPM SCRIPTS it doesn't work.
MORE DETAIL AS REQUESTED IN COMMENT
// Edit by Fogmeister
I also have this problem, here is some more detail...
I have a test script defined in package.json...
When I run this script from the root folder command line using npm run test it works...
This script appears in the list of NPM Scripts in VS Code...
When I run from the NPM Scripts explorer it fails...
Even though it says it is running from the same folder.
Try doing, use dnf or apt-get
sudo apt-get/dnf install npm
The npm file should be in /usr/local/bin/npm. If it's not there, install node.js again with the package on their website.
Does npm i -S <pkg/module> or yarn add <pkg/module> also runs the start script written in the package.json of that specific pkg/module?
No, it just installs the package recursively and add it to your package.json
https://docs.npmjs.com/cli/install for reference
The script postinstall is run after installation
https://docs.npmjs.com/misc/scripts for reference