Develop Reference

Deploying a NestJs project on a single board computer (Raspberry or similar)

even if it seems a simple task I'm having some trouble finding a solution. I know that with Nest CLI I can use the command "nest build" in order to create a dist folder that contains the production files of my project.
The problem is when I move the folder on my Raspberry and i try to run the project with the command "node dist/main" following NestJs instructions. Nothing starts because node says that it cannot find #nestjs/core and other modules.
I did't find nothing clear in the official guide about deploying the app, so my question is: what do I need to move onto my rasperry in addition to dist folder? Do I need to reinstall all node_modules folder or it's possible to have a running project without have to reinstall 800Mb of modules?

Yes you need to run yarn or npm install on your production environment, as your dist folder only contains your own code.
Because unlike compiled language like Golang where all dependencies are bundled and compiled in you executable file, Javascript bundlers don't. Your bundled code in dist still contains require or import statement to get dependencies from node_modules.
You can also run npm prune --production to remove any developpement dependencies and thus reduce the size of your node_modules folder. (I believe that yarn does it by default.)

Install a library by using npm on a server

when i want to use some library, such as Croppie, i should install it by using npm or Bower:
npm install croppie
bower install croppie
As i am using a server, i dont know where is should install it. On the server? in the wordpress files? or in the same folder that contains JS file for this library.
Thanks a lot

Basically you need to add script in your wordpress web app. So there are multiple ways to do so.
1) Add <script src="https://raw.githubusercontent.com/Foliotek/Croppie/master/croppie.min.js" />. It's better either you download this file in your file system or add a CDN link of Croppie.
2) If you have bower.json configured in your project you can use bower install croppie and then link it in your index.php (root file)

If you just have copied your project over to your server, you should have a package.json file, which contains all libraries you used. (Given you saved it via npm install croppie --save or npm install croppie --save-dev)
Then you can just go into your directory which contains the package.json and run npm install.
If you ever install a library which you would like to use without a project, you can install it globally with npm install libraryName -g, thus making it available on the command line.

In general, if you develop locally and deploy to a server, you should install dependencies locally, in /wp-content/themes/(your-theme)/ and don't upload them to your web server along with the rest of the site. The .bowerrc file, placed in the theme directory, should include the target directory in which bower will place the dependencies you've required:
{
"directory": "bower_components"
}
Then you'd want to bundle those dependencies in css/js etc. directories within the theme and deploy those. .gitignore the bower_components directory or just don't FTP that directory up, depending on how you do things.

Conditionally include dist directory with NPM module

I have an NPM package that can be used with the browser. But in order to use it in the browser, I pre-package it using Webpack and put the browserified code in the /dist directory.
Normally, I don't feel it's necessary to include the /dist directory when publishing to NPM, unless someone wants to use the browser version instead of the Node.js version (most of my customers will be using my lib for Node.js not for front-end).
The dist is a huge directory (all the project's code, plus NPM deps) and I want to save people the disk space and install time.
Should I just create a separate package for the browser code, or is there some flag I can use for conditionally including the dist directory when people install my package?

I believe it's better to create two separate packages.

How to verify an object instance? instanceof and ....prototype.isPrototypeOf(...) are not reliable [duplicate]

Whenever I make projects, I have to download all dependencies of node modules. Without copying the node_modules, Is there anyway to share the central node_modules in multiple projects?
like the followings, I have to run many commands every time..
npm install gulp-usemin
npm install gulp-wrap
npm install gulp-connect
npm install gulp-watch
npm install gulp-minify-css
npm install gulp-uglify
npm install gulp-concat
npm install gulp-less
npm install gulp-rename
npm install gulp-minify-html

You absolutely can share a node_modules directory amongst projects.
From node's documentation:
If the module identifier passed to require() is not a native module,
and does not begin with '/', '../', or './', then node starts at the
parent directory of the current module, and adds /node_modules, and
attempts to load the module from that location.
If it is not found there, then it moves to the parent directory, and
so on, until the root of the file system is reached.
For example, if the file at '/home/ry/projects/foo.js' called
require('bar.js'), then node would look in the following locations, in
this order:
/home/ry/projects/node_modules/bar.js /home/ry/node_modules/bar.js
/home/node_modules/bar.js /node_modules/bar.js
So just put a node_modules folder inside your projects directory and put in whatever modules you want. Just require them like normal. When node doesn't find a node_modules directory in your project folder, it will check the parent folder automatically. So make your directory structure like this:
-myProjects
--node_modules
--myproject1
---sub-project
--myproject2
So like this, even your sub-project's dependencies can draw on your main node_modules repository.
One drawback to doing it this way is you will have to build out your package.json file manually (unless someone knows a way to automate this with grunt or something). When you install your packages and add the --save arg to an npm install command it automatically appends it to the dependencies section or your package.json, which is convenient.

Try pnpm instead of npm.
pnpm uses hard links and symlinks to save one version of a module only ever once on a disk.
If you have npm installed, you can install in your terminal with:
npm install -g pnpm
To update your existing installations (and sub-directories) use:
pnpm recursive install
Or use the shorthand command (leave off -r if you need to target only one directory)
pnpm -r i
One helpful note: You may find some rare packages don't have all their dependencies defined. They might rely on the flat node_modules file directory structure of npm or yarn installs. If you run into issues of missing dependencies, use this command to hoist all the sub dependencies into a flat-file structure:
pnpm install --shamefully-hoist
It's best to avoid using the --shamefully-hoist flag as it defeats the purpose of using pnpm in the first place, so try using the command pnpm i your-missing-package first (See pnpm FAQ).

I found a trick, just take a look at the Symbolic Links (symlinks) on Windows or Linux, it is working just like shortcuts but more powerful.
Simply you need to make a Junction for your node_modules folder anywhere you want. The junction is nothing but a short cut to your original node_modules folder. Create it inside your project folder where the actual node_modules would have been created if used npm install.
To achieve this you need at least one node_modules real folder then make a Junction to it in the other projects.
On Windows, you can either use the Command Prompt, or use an application. Using the Command Prompt gives you a bit more control, using an application is easier I suggest Link Shell Extension.

Main directory should look like this
node_modules
Project 1
Project 2
Project 3
Project 4
just open the file Project 1/.angular-cli.json
change the schema
"$schema": "./node_modules/#angular/cli/lib/config/schema.json",
to
"$schema": "./../node_modules/#angular/cli/lib/config/schema.json"
and don't forget to create node_modules empty folder inside your project directory

See also npm v7.0.0's support for workspaces
RFC
https://github.com/npm/rfcs/blob/latest/implemented/0026-workspaces.md
Documentation
https://docs.npmjs.com/cli/v7/using-npm/workspaces

By looking at some articles it seems that Lerna
is a good tool for managing multiple projects inside a single directory (monorepo). It supports modules sharing without duplicating the entire packages in every folder and commands to install them in multiple projects.
Javascript monorepos
Monorepos by example
Building large scale apps in a monorepo
pnpm is also a simple and efficient tool, which doesn't duplicate those modules which are already installed for other projects.

Let's assume that having a single node_modules it should contain all the packages for all applications. thus your apps will also share most of the unique package.json entries (just the name should change)
my idea would be to have a single root and multiple src level as below
root\package.json
root\node_modules
root\\..
root\app1\src\\..
root\app2\src\\..
the only issue you might face would be having a backup of json (or tsconfig) for any app and restore them when you work on it or setup your startup scripts to serve any app

Node.js project with no package.json

Is it ok to have a node.js project with no package.json? The ones I see on the internet all come with package.json
What is the effect of having no package.json?
How is package.json created in the first place? Is it created automatically? I am wondering why I do not have package.json

Fundamentally, package.json is a meta file for your application. It lists all the configuration of your application.
What is the effect of having no package.json?
Nothing as far as you're running all your code locally and have no requirement for deployment whatsoever.
Let's setup a scene for you to understand this better.
Imagine that you wrote a brilliant application using node. Now all the chicks in your surrounding want it to play with. It is so fantastic!
Now you want to give it to them and during the development process you `npm install`ed so many things that your project grows beyond 4TB size.
There is no data storage device available to ship that huge code base.
Then the girl of your dream said I want it and I want it now. So you begin searching for app deployment process for node applications.
That is where you stumble upon a magical thing called package.json.
So what you do is you list all your npm installed modules under dependencies property. Then you delete node_modulesfolder, add package.json and commit the entire damn thing in github. Even the .zip file is of 10MB
Then she gets the code.
Types in npm install && npm start (which will install all the dependencies from the package.json` and start your application)
If you have package.json however, that is where you specify all your dependencies.
Using --save flag of npm install
Example.
npm install express --save
How is package.json created in the first place? Is it created automatically?
You can manually create a text file and save it as package.json
OR
A more sophisticated way is to use the command
npm init
I am wondering why I do not have package.json
Me too! :)
You're most probably following a tutorial that doesn't emphasize on initial configuration of the project OR the author of those tutorials presume that the reader has all the fundamentals down to begin with.

It is created automatically if you write npm init.
Then, every package you add using npm install packagename --save will be added to the dependencies list.
You need package.json so that when you want to use your project on another machine you don't have to copy all node_modules, but only your .js files you have written, assets and package.json. You can then run npm install command and it will automatically download and install all the required modules (found in the list of dependencies inside package.json).
You can also manually create or edit it, but it's easier to add --save when installing a module so you don't have to worry about package versions and stuff like that.
Also if you want to create a npm package, an open source project or stuff other people will use, it's either required or the norm to have this package.json file describing your project.

package.json is npm file, if you don't use npm you will not have this file, npm is a great tool if you want to use external libraries in your project but if you don't need it (which is very not likely unless you are doing something very simple), you don't need package.json file too.
To generate package.json file initialize npm in your project using npm init

possible reason thus it exist is you maybe you enter a wrong command like npm i -y, you must initialize the project first, just enter a command npm init -y
Welcome.

Well, if you are running it on your local machine, it's fine. now to answer your last question, package.json is not created automatically.
the npm command npm init -y creates the 'package.json' file. It basically makes sharing your code and installing your codebase easier.