I have just started using yarn and I can't figure out how to link a globally installed package to a project. With npm I would just run npm link <package-name> but it doesn't work with yarn.
when I run yarn link <package-name> it gives this error:
yarn link v1.22.4
error No registered package found called "express".
info Visit https://yarnpkg.com/en/docs/cli/link for documentation about this command.
The link functionality is not really meant for linking global packages to a project. It is meant to link a package that you are working on to another project that you are working on. The fact, that the npm link command can be used to link globally installed packages to the current project is just an implementation detail of npm. From the yarn docs:
For the vast majority of packages it is considered a bad practice to have global dependencies because they are implicit. It is much better to add all of your dependencies locally so that they are explicit and anyone else using your project gets the same set of dependencies.
So you should just add the dependencies via yarn add <package-name>.
Related
I'm trying to run a simple hello.ts script from command line. This works if the script has no dependencies:
npx ts-node hello.ts
But as soon as I start adding some dependencies...
import _ from 'lodash';
console.log('hello');
It fails:
Cannot find module 'lodash' or its corresponding type declarations.
It keeps failing even if I install the dependencies globally. So how do I tell npx (or ts-node for that matter) to consider globally installed dependencies?
Update
Using Node 16.9.1 (upgraded via Version Lens). The error seems to have disappeared after uninstalling/reinstalling the imported libraries a few times.
If you're using npm >=1.0, you can use npm link to create a local link to a package already installed globally. (Caveat: The OS must support symlinks.)
IE: npm install -g lodash && npm link lodash
However, this doesn't come without its problems.
npm link is a development tool. It's awesome for managing packages on your local development box. But deploying with npm link is basically asking for problems, since it makes it super easy to update things without realizing it.
As an alternative, you can install the packages locally as well as globally.
For additional information, see:
https://nodejs.org/en/blog/npm/npm-1-0-link/
https://nodejs.org/en/blog/npm/npm-1-0-global-vs-local-installation/
Are you using the n package by any chance? I used n to change from a newer version of node (16.2.0) to an older version of node (12.13.0), ran npm i and npx failed with a different error.
Using n to change back to 16.2.0 seems to have resolved the issue so I'm thinking perhaps it was an issue with package-lock.json or such
I am studying about npm and I have some questions.
Where the npm get the package from? i.e. when run npm install <package-name> or yarn add <package-name>.
When get the package, do npm get the package as raw or get then build it(like run the build script written in package.json)?
When publish the package, the repository field of package.json is required?
Can be different between the repository for publishing and the repository in pacakge.json?
To answer your questions:
npm gets them from the NPM package registry, and so does yarn, but Yarn probably has a proxy registry in front of it. In general, you can say, both tools fetch their packages from https://npmjs.com by default.
It gets the package as it was published (so, in short, the answer is "raw"). Building is up to the publisher and depends on the type of package. Often, some prepublish task builds something into dist/ (or any other location in the package), and these files are also shipped with the package others then download. Building rarely happens after installing a package (exception here are library-wrapping packages built with node-gyp).
The repository field is not required, to my knowledge, but it is good practise to include it (it will be displayed on the NPM website, for example).
Technically, yes. You can just specify any repository in repository, but it wouldn't make much sense to specify one that isn't the source of the package.
If you in general want to read up more on how npm works, check out it's documentation over at https://docs.npmjs.com/
I'm new to nodejs and npm, just a question on dependencies and devDependencies
When I create a new react or Angular project, then I added a new required package by
npm install xxx --save
so the command above add the new package entry to "dependencies" in package.json file.
then I run npm start. The project is working OK and it is using the package I just installed.
But when I run npm start, I'm still in development environment, isn't it? and if the entry is not added to devDependencies, how can the application still run in development? I'm confused
The difference between these two, is that devDependencies are modules which are only required during development, while dependencies are modules which are also required at runtime. So while development we use both of them. For more details check here.
If you have a project that depends on packageA and you yarn add packageA but packageA has a devDependency on packageB to build, shouldn't that cause packageA to not work for you? Since packageA won't be able to build unless its devDependencies are installed too?
I guess my main question is if a pacakge has a devDependency on a built tool like babel, how does it get built and work when it gets yarn added by a project? Shouldn't build tools like webpack be a normal dependency?
No, they shouldn't, because the package that is yarn added is already built in an environment where the devDependencies are available. For example, when a package needs babel or webpack to build, then during the publishing a built bundle is created in a CI/CD pipeline that is valid es5 code and that is what you pull from npm. No build required after that.
GOOD MORNING :)
If you are having dependency problems on your dependencies of package.json, it is very simple to solve =]
What happens is that the dependency modules that the modules of your project need (dependencies) must be installed in the global npm as a package node (module), that is:
npm install -g youPackageName
If you have already installed a module in other projects or in the current project and want to turn it into a global package, you can use the command:
npm link youPackageName
I checked out a repo which uses yarn instead of npm as build tool.
in the package.json, it defines workspaces to deal with multiple sub-projects:
{
"workspaces": [
"packages/*"
],
"dependencies": [],
"devDependencies": [
// long list
]
}
As a result, the root package.json does not contain any runtime dependency. Just the packages/*/package.json contain those.
To compile (and start in dev mode) I do:
yarn install
yarn start
I have found no documentation, that workspaces is also recognized and correctly used by npm.
Is there a way to make it work with npm, too?
Now that npm v7.0.0 is out, npm supports workspaces. You can manage multiple packages from within a singular top-level, root package. See more at https://github.blog/2020-10-13-presenting-v7-0-0-of-the-npm-cli/
Your workflows will not get npm v7.0.0 by default unless you install it using npm install -g npm#7.
Managing dependencies in a monorepo is not supported with npm. The Lerna package is used to manage JavaScript projects with cross dependencies. I believe Lerna uses Yarn under the hood, but with Yarn as your project's package manager, this feature is supported out of the box.
Here is a repo that might be helpful to see how Yarn and Lerna work together: https://github.com/Quramy/lerna-yarn-workspaces-example
npm has plans to implement workspaces somewhere along the v7, hopefully. They've written about it in their blog and there's an accepted proposal.
As of 2020-08-11 Workspaces are available in the v7 beta.
RFC 26 First phase of workspaces support is added. This changes
npm’s behavior when a root project’s package.json file contains a
workspaces field.
https://blog.npmjs.org/post/626173315965468672/npm-v7-series-beta-release-and-semver-major
You can view and download the beta here:
https://github.com/npm/cli/tags
NPM version 7 support workspace management. Now we can manage our workspace dependencies using npm workspace.
More on the workspace support can be found here official site here.
https://docs.npmjs.com/cli/v7/using-npm/workspaces
If you are looking for a simple example follow this link
https://github.com/pravanjan/npm-workspace-example/tree/master
Tested using node v16.6.1
npm 7.20.3