I have been using NPM exclusively for my projects and was assigned another project that requires using Yarn. I need to have support for both and will frequently switch back and forth on projects.
Are there any known issues with installing yarn globally and still using NPM on other projects?
super awesome, there are no such conflicts using yarn and npm together.
because yarn and npm both have different installation directories.
for global packages, you can use both, but don't forget to stick to one. we use yarn for our production.
for non-global packages, it is beneficial to stick to what the project author uses.
it becomes difficult sometimes if you have yarn.lock and package.lock file together, because there is a risk of being out of sync. for example, someone updated one package using yarn, someone will not get that changes who use npm and so on.
Yarn and npm are interchangeable. As long as you use the same one each time, there is no difference between them. They have different install directories, which is why they can't be used together. Yarn will install a package, npm can't find it. npm will install a package, yarn can't find it.
it is a more beneficial and good habit to use one package for each project to make sure that all packages are installed correctly, Having half your packages installed with yarn will stop npm start from working; having half your packages installed with npm will stop yarn start from working.
also always use the same one for global too, it does not matter what you use yarn or npm. it does not matter to your global install.
Related
I am now in charge of an app whose dependencies were installed using yarn. I am more familiar with NPM. Is switching over as easy as deleting the yarn.lock file and installing NPM to the project? The app hasn't been updated in a year or two so I'm trying to update everything.
Or maybe a better question is, can I install both NPM and yarn globally but pick and choose which one I use for what app? Will it cause issues if they are both installed globally on machine?
Thanks in advance
You can definitely have Yarn and NPM installed on the same machine without issue. NPM generally comes packaged with Node, so most people using Yarn will also have NPM installed, wether they use it or not.
In terms of switching a project from Yarn to NPM, it's a pretty straightforward process, like you described: remove yarn.lock and remove the existing node_modules directory just to avoid any issues.
The subtle issue here is that the yarn.lock will be the current source of truth for exactly which versions of each dependency (and sub-dependencies) is installed. So by removing the yarn.lock your package.json will now become the (incomplete) source of truth which will likely result in some dependencies being upgraded when you perform your first npm install -- then your package-lock.json will become the new strict source of truth.
Given you're planning on updating everything anyway, then this likely isn't going to be an issue, but it's worth keeping in mind as you're likely to see some minor dependency changes.
when running npm install --no-optional, it takes around 3 mins every time to complete. It installs ~ 200MB of files. I would like to speed the build process, but I cannot find any ways to really speed it up.
Doesn't npm install by default cache dependencies (like any other decent tool e.g. maven, sbt or nuget) by default? If yes, shouldn't it be much faster than that? If no, then WHY and how to work around that?
I found npm-cache package, but it seems to .tar all the dependencies and when neither of them changes, npm-cache will reuse the tar file. The downside of this is that, whenever a small change in dependencies occurs, it won't be able to reuse the cache (from what I understand).
Are there any nice resources on why this is slow and how to speed it up and how caching works with npm in general? Other tools that I have used (sbt, maven, nuget) are much faster, therefore my expectations are high for npm as well.
Another option I looked into is npm install -g, but it seems not to solve any problems here, as it is meant to be used for installing some cli tools like grunt, npm-cache and etc., as it adds them to a path. So this definitely doesn't solve the problem.
npm -v: 4.0.5
node -v: 6.8.1
The problem with node was that coming from sbt background, where sbt uses a local ivy cache to cache dependencies, I expect the same behaviour from Node. So at least up to V 5.0, Node didn't have a proper dependency caching mechanism, so you basically needed to redownload all of the dependencies every time you do a node install with a clean node_modules folder.
There were some tool developed to work around that, but none of them were satisfactory.
But it seems that this might have been fixed in Node V 5.0 with some caching strategy, therefore if you have a similar issue, please take a look at the changes for the 5th version.
It's better to install pnpm package using the following command:
npm i -g pnpm
pnpm uses hard links and symlinks to save one version of a module only ever once on a disk. When using npm or Yarn for example, if you have 100 projects using the same version of lodash, you will have 100 copies of lodash on disk. With pnpm, lodash will be saved in a single place on the disk and a hard link will put it into the node_modules where it should be installed.
As an example I can mention that whenever you want to install the dependencies of package.json file, what you should do is simply that enter the pnpm i and it handles the other things by itself. Its speed is faster than the npm, because it will reuse the dependencies that you've installed them before!
I work in a team of about 20 other developers. All of our projects utilize npm packages and currently all of our developers are running npm to manage those packages. I'm very curious about Yarn and have it currently installed on my machine. However I'm nervous to actually use it to install packages in case it screws up a project for other developers.
My question is can one developer utilize Yarn on a project while other devs are using npm in the same repo? From what I've read, Yarn uses the same package.json file to get its dependencies. We ignore the node_modules in our repo, however we use npm shrinkwrap to lock dependencies. I know Yarn has a Yarn.lock file and that is where my concern lies. Has anyone attempted to run Yarn independently from their team and what issues have you run into?
Yarn doesn't read npm-shrinkwrap.json. It generates its own yarn.lock. While only you use yarn, the project in your environment might have dependencies version different then that your teammates have. However it's safe to try yarn in your own environment since it doesn't overwrite shrinkwrap file and won't impact other developers.
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
According to Heroku I should avoid global dependencies when asking Heroku to build my project. But I still want Bower and Grunt on the command line.
My question is: how then should I be running these tools?
Rather than installing them with npm install -g, should I be adding paths from node_modules to PATH, or the like? (Ubuntu)
If Grunt/Bower are installed globally on development machines -say when someone new starts on the project -then presumably npm install -g grunt-cli might give a different Grunt version to what's in package.json. Hence what Heroku runs and what developers run might accidentally differ.
(Or is that unlikely to be a problem?)
The best practice is to keep everything local, with npm install --save.
That way you can align versions for everyone in the team simply by tweaking the package.json file.
If you only need Bower and Grunt etc. to be available in your dev environments, then install them with npm install --save-dev. This will cause them to be saved in a devDependencies section in your package.json. Dependencies referenced therein will not get distributed to production (e.g. Heroku), but will be available in all your dev environments.
If you really do need Bower and Grunt etc. to be available on Heroku, then install them with npm install --save.
At any rate, npm should automatically save symbolic links to your executables (e.g. grunt-cli) in directory node_modules/.bin, and should take care of adding node_modules/.bin to your PATH, so you don't have to worry about that.