I would like to install the types when using tensorflow/tfjs-node as I'm using Typescript.
I installed it via npm install #tensorflow/tfjs-node
But non of them are working to install the typings:
npm install --save #types/tensorflow/tfjs-node
npm install --save #types/tfjs-node
You don't need to install the types separately as they come already bundled with the main repository.
To remove the old typings from #types/... use npm uninstall. After that, When using TypeScript and importing the data via import it should automatically pick up the correct types.
Related
As mentioned, I was wondering how useful it is to use npx. From what I've read, npx executes packages without downloading them, it doesn't seem right, since the packages are found in: ~/.npm/_npx (first time when using npx with a package, it asks if you want do install that package, and after that, when using that package, it doesn't ask anymore:Example with cowsay)
So, if I am right, it is the same as installing that package globally, using npm install -g. So what is the point of using npx when we could install that package globally and the using it?
I just setup a test, and tried to npm install express even though express already exists globally on my system. To my surprise, instead of using the global version, it ended up re-installing a version locally!? Isn't it supposed to use the global version... Or am I suppose to use -g every time, even when I only want to use the existing global version. Otherwise, what's the point of installing anything locally!?
The answer is "NO". It isn't supposed to use your global version.
If you want to use your global version, then you doesn't need to execute npm install at all because it is already installed.
If you do it then, obviously, you are saying "I want to install it locally to my project". And more than that: "I want to install its latest version unless it is declared in my package.json with other explicitly specified version".
In fact, the actual question is: Why in the hell would you want to not install a dependency of your project locally? To have more version mismatch issues?
As #anshuman_singh says, best practice is to always do an npm install --save.
You are able to use globally installed packages, of course. It could be handy for fast testing code that you will drop just after a few hours or so.
But, anyway: If you doesn't have really hard disk or network bandwidth issues, installing all dependencies locally will avoid you too much trouble in the future.
On the other hand, uploading that modules to your code repository is also a bad idea (maybe that is what you were trying to avoid) because, with different versions of node, most native modules won't work if not rebuild. But most VCS support ignoring files and or directories that must not be uploaded.
For example, in git (.gitignore file):
**/node_modules
In summary:
npm init (if you didn't already it).
npm install --save for all your project dependencies.
npm install --save-dev for dependencies not needed in production (testing stuff).
Don't upload node_modules to your VCS.
After new checkout: npm install or npm install --production (to not install dev-dependencies).
npm install -g only for tools you will use in console.
This way, you are sure that you will have in production (or other dev environments) the exact same version of each package.
And, finally, if you ever want to upgrade some package to its latest version, simply run:
npm install --save <pagkage_name>#latest.
If you’re installing something that you want to use in your program, using require('whatever'), then install it locally, at the root of your project.
If you’re installing something that you want to use in your shell, on the command line or something, install it globally, so that its binaries end up in your PATH environment variable.
The first option is the best in my opinion. Simple, clear, explicit. The second is really handy if you are going to re-use the same library in a bunch of different projects
Install locally-
npm install moduleName
install locally and save in package.json-
npm install moduleName --save
install globally-
npm install moduleName -g
I am new to Electron (Atom-shell), and I am trying to load a NodeJS plugin into the application I am building, but I don't know how. The documentation is not clear on that.
For instance, I am trying to use sqlite3 plugin in my app, I used npm install sqlite3, and it was successfully installed. But the application throws and error when I try to call it var sqlite = require('sqlite3'). Are there any further steps I am not aware of ?
Thanks.
For pure JS (i.e. not native) modules you need the following:
Have the module listed in your package.json dependencies
Let electron know where to find the module (e.g. export NODE_PATH=/PATH/TO/node_module)
The first requirement is obvious and the second has its roots in this issue.
For native node modules (such as sqlite3) which use C++ bindings, you need to build them against electron headers to work. According to electron docs, the easiest way to do that would be:
npm install --save-dev electron-rebuild
# Every time you run npm install, run this
./node_modules/.bin/electron-rebuild
To install the npm modules correctly you should go into the folder of your electron app and install the module via npm.
npm install --save sqlite3
The flag --save is important, because npm will install the module inside your app.
Afterwards the require should work.
I understand the differences between npm install something and npm install something --save (for anyone wondering, the first one will install the dependency only while the latter will install the dependency and add it to your package.json).
However I do not understand why there is a --save option in the first place. In other words, why would you ever want to install a dependency without adding it to your package.json file? Why is the --save option not default?
A lot of websites/npm modules/SaaS suggest installing their module using npm install something (newrelic is one of them for instance), am I missing something?
Edit: Starting from NPM 5, --save is now on by default.
You would have a scenario such as you need some module to install without adding dependency to package.json file, for ex. you just want to try some module, and not sure you would be really using that module in production or while deploying, so instead adding the module dependency to package.json, just give it a try without using --save. this is why npm install without --save exists.
But For most of your modules you might require using --save, for ex. npm install express --save,
in this case you surely know that you are going to use express for you application.
The other scenario, for not using --save, would be, npm install heapdump or npm install nodemon, I would use it for testing my apps performance, but not add a dependency in the package.json :)
Also, As #surajck said in comment below: when you are doing global installs, in that case adding dependencies using --save, to the package.json would not make sense.
I just learned a nice trick from Jonathan Mills' JavaScript Best Practices course on Pluralsight. From the terminal:
npm config set save=true
Now I don't need to remember --save anymore. And I also now use
npm config set save-exact=true
Because I want the exact version of the package not the ^ prefix.
By default with version npm 5.0+ npm install adds the module to the dependencies list in the package.json file; with earlier versions of npm, you must specify the --save option explicitly. Then, afterwards, running npm install in the app directory will automatically install modules in the dependencies list.
I've just started using Grunt.js. It is pretty hard to set up and I am at the point of creating a package.json file.
Following this tutorial, it says there are 3 ways to create a package.json file.
The first is to do npm install grunt --save-dev
But what does --save-dev means? I tried looking but it ends in vain.
--save-dev: Package will appear in your devDependencies.
According to the npm install docs.
If someone is planning on downloading and using your module in their program, then they probably don't want or need to download and build the external test or documentation framework that you use.
In other words, when you run npm install, your project's devDependencies will be installed, but the devDependencies for any packages that your app depends on will not be installed; further, other apps having your app as a dependency need not install your devDependencies. Such modules should only be needed when developing the app (eg grunt, mocha etc).
According to the package.json docs
Edit: Attempt at visualising what npm install does:
yourproject
dependency installed
dependency installed
dependency installed
devDependency NOT installed
devDependency NOT installed
devDependency installed
dependency installed
devDependency NOT installed
There are (at least) two types of package dependencies you can indicate in your package.json files:
Those packages that are required in order to use your module are listed under the "dependencies" property. Using npm you can add those dependencies to your package.json file this way:
npm install --save packageName
Those packages required in order to help develop your module are listed under the "devDependencies" property. These packages are not necessary for others to use the module, but if they want to help develop the module, these packages will be needed. Using npm you can add those devDependencies to your package.json file this way:
npm install --save-dev packageName
To add on to Andreas' answer, you can install only the dependencies by using:
npm install --production
When you use the parameter "--save" your dependency will go inside the #1 below in package.json. When you use the parameter "--save-dev" your dependency will go inside the #2 below in package.json.
#1. "dependencies": these packages are required by your application in production.
#2. "devDependencies": these packages are only needed for development and testing
Documentation from npm for npm install <package-name> --save and npm install <package-name> --save-dev can be found here:
https://docs.npmjs.com/getting-started/using-a-package.json#the-save-and-save-dev-install-flags
A package.json file declares metadata about the module you are developing. Both aforementioned commands modify this package.json file. --save will declare the installed package (in this case, grunt) as a dependency for your module; --save-dev will declare it as a dependency for development of your module.
Ask yourself: will the installed package be required for use of my module, or will it only be required for developing it?
For me the first answer appears a bit confusing, so to make it short and clean:
npm install <package_name> saves any specified packages into dependencies by default. Additionally, you can control where and how they get saved with some additional flags:
npm install <package_name> --no-save Prevents saving to dependencies.
npm install <package_name> ---save-dev updates the devDependencies in your package. These are only used for local testing and development.
You can read more at in the dcu
–save
The package installed is core dependency.
–save-dev
The package installed is not a core rather development dependency.
Use only when developing
--save-dev means omit in production environments, use only in development environments (smaller, and probably faster).