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This thread aims to expose our roadmap for the next major Yarn release, and let you know about significant changes that we plan to make regarding Yarn's design. The codename for these changes is Berry - that's how we'll refer to it during the next few months.
This section lists some of the work we have in progress. It's far from being a comprehensive list, but it gives a good idea of the kind of changes you can expect going forward:
And of course, a large amount of bugs are also expected to disappear as we modernize the codebase. A lot of those were caused by intricacies in the various components making up Yarn and, by cleanly separating them into standalone steps, we expect the overall logic to become much clearer and less error prone.
As you might guess, this isn't a comprehensive list - we plan Berry to be the big refactoring that Yarn had needed for a while now so many internal systems will be reworked. After that we expect following majors to become much smaller, as we'll have strong foundation for building new features and reworking the project one component at a time.
Now that we've discussed about most of the "What", let's discuss about the "Why". First, those are the values we always believed in and around which we continue to design most of our features.
This is our number one motto. We believe that Yarn should have a totally predictable and reproducible behavior. That your package manager has a responsibility to warn you when your project relies on unsafe patterns that could jeopardize your application at the worst possible time.
Contributing to the Yarn ecosystem should be simple
Because a single project will never be able to satisfy all the needs from all developers counting on us, various projects spawned and grown, reinforcing Yarn rather than competing against it. Some examples are Create-react-app, Lerna, OpenCollective, or patch-package. We like that approach and want to give you the tools to do even more in a more efficient way. Not all features belong to the core, but being able to innovate and experiment is at the core of our philosophy, and we really mean it.
Goals for 2019
Now that our values are clear, what are the next steps we need to do in order to reach our goal? Note that some are long-term, some short-term, and that all are open to discussion (ideally in separate threads, otherwise it might get noisy
Yarn will become a development-first tool
We've been saying it for some time now, but now we're ready to start going for it. Package managers are not tools you should ever run on your production servers. The more code run there, the higher are the probabilities that something will eventually go wrong and bring your production systems down. Yarn being development-first means that we'll make it possible for you to reach the state where you clone a repository, and voilà. This includes putting the emphasis on Plug'n'Play, which has been designed with this specific use case in mind.
Yarn will be rewritten in TypeScript
Yarn is currently fully covered by Flow types, and to be honest it works pretty well for us - the key part being “us”. Because we want to make it as easy as possible for third-party contributors to shim in and help us maintain this awesome tool, we'll switch the codebase to TypeScript. We hope this will help making the codebase feel more familiar than the projects your already contribute to.
Yarn will become an API, and its internal components will be split into modular entities
This one is huge. At the moment, when working with Yarn, your only option is the command line interface. We don't offer primitives that allow you to take advantage of the complex logic we've implemented - whether it's the resolvers, linkers, or even accessing the configuration. This will change, and Yarn will be redesign to become an API first and a CLI second.
Yarn will be designed to support different install targets than Node
Package management is a problem that keeps on being reinvented - even Yarn itself did it in the past. We believe the reason for this is that all package managers need to layout the installed packages in slightly different ways in order for them to be read by the host. This unfortunately is rarely possible, and it ends up being easier to rewrite the package manager and discard the already-existing user experience and features. Starting from Berry, we made it an explicit goal that each component of our pipeline can be switched to adapt to different install targets. In a way, Yarn will now be a package manager platform as much as a package manager. If you're interested into implementing PHP, Python, Ruby package installers without ever leaving Yarn, please open an issue and we'll help you get started!
Overall compatibility will be preserved when possible
Such semver-major changes are by design backward-incompatible, but we'll make sure to keep them to an acceptable level. In particular, the core command (
When will it be released?
We'll open a new repository early February with the v2, the time to flesh out some remaining interfaces. Starting from then, we'll make Berry accessible simply by running
What will happen to the v1?
As mentioned before, Berry won't have a stable release until this summer, and work will continue on the v1 until then. Even after Berry comes live, the v1 branch will still stay well maintained for the foreseeable future, perhaps distributed through a codename. This will ensure that your applications that work now continue to work in the future, until you feel ready to move to the v2.
How can i help?
The biggest way you could help us at the moment would be to enable PnP (
[*]: Lack of
It may appear to work out of the box sometimes but that's only for types published in DefinitelyTyped which are fetched in the background by the IDE.
This small bit of negativity aside, really looking forward to the future, in particular to better workspace workflows
And, who knows,
That sounds promising. Does that mean no more need for things like cross-env to be able to do
Does this also mean that the
Or will Yarn still depend on the
It would be awesome if Yarn can be used on projects built for NPM.
Ah ah, good question - no (mostly), and yes (but not really)
The new architecture will see its components moved into various packages - for example
The core package will not support anything else than
That being said, I guess you could reimplement the core and read from the
So when a package will be linked into a project, even if the package finds it's dependency in it's surrounding before finding it in the project, it will use the peerDependendy provided by the project anyway? Ref: #6888
Does it means it will be required to use Yarn PnP to use this feature ?
Anyway, thanks for the share this list is awesome!
Yes, this is only possible because PnP is aware of the full dependency tree (when it would otherwise be Node that would try to locate the link dependencies, based on the realpath).
@arcanis Stepping away from the "using the same package-lock.json file" question; was it considered to use the same format as npm's package lock? Or a superset of it?
I really like yarn.lock becoming programmatically accessible as YAML, but using the same format would make it easier to read both using the same tooling.
Yes, but as I mentioned the npm format has (what we believe are) design flaws that make it incompatible with our goals. We've already got this discussion in the linked thread
I understand completely that it can lead to unexpected results, but as long as its logic can be overwritten with plugins, it can be easier to migrate and convince others to use Yarn on already existing NPM and Composer projects. But of course, only with the help of plugins; this helps keep the core stable.
This is great.
Yarn will become an API, and its internal components will be split into modular entities
This is by far the best thing IMO especially combined with plugins.
Here is a common problem I run into, and maybe there is a configuration based approach to fixing it but I've always relied on custom scripts
For example, a in workspaces project layout like
If multiple teams or developers are working on this, there are some who are constantly touching layouts, and components, others who primarily work on themes, and others who build apps using these dependencies.
yarn workspace's behavior where it symlinks to the local project instead of the npm dependency is great, however it makes it so if I clone this repo from scratch and want to work on an app, I have to build all the themes, layouts, etc as well
i've worked around this with custom scripts, but they're hard to maintain, feel wrong, and involve a lot of shelling out to yarn to do work.
i think plugins + an api for yarn would make this so much cleaner.
Keep up the great work. This is one of the most exciting roadmaps i've seen in a while for a project.
Fantastic @arcanis, I tried to replace the
A plugin structure sounds great. I'd be happy to make a
Update: I've published the trunk for the v2 on a separate repository (at least for now, in order to better triage issuers): https://github.com/yarnpkg/berry
It's already working mighty fine, but as you can guess we've still some way to go until we can call it a day. At the moment I'd say most of the remaining work are missing features (like
When it's done!
More seriously it's quite stable already - it can easily install itself, and I use it daily. There are still some important tasks that need to be done in order to start releasing it more widely, and any help we can get would be seriously impactful. I've listed various tasks in our issues and would be happy to give more details over there! Even documentation writers or early adopters would put us miles ahead
Overall, my target would be to have an official release somewhere this summer, but it might shift both ways depending on the progress and other external factors.
Following thoughts are more of a feature request.
Right now, yarn is installed via package managers on a machine.
What about a portable yarn wrapper?
What's the problem I'm trying to solve?
What's my current idea?
$ ./yarnw install Welcome to the portable yarn wrapper - best in town! Checking ~/.yarn/wrapper/node_versions/10.15.3 Node 10.15.3 already installed. Ready to go! Checking ~/.yarn/wrapper/yarn_versions/1.15.2 Downloading yarn 1.15.2 from https://yarnpkg.com/<version>.tar.gz Downloaded. Running yarn install (would execute ~/.yarn/wrapper/node_versions/10.15.3/node -e "require('~/.yarn/wrapper/yarn_versions/1.15.2/libexec/lib/cli.js').default()" ??? ) yarn install v1.15.2 <usual yarn experience> <...> Stars Done in took-some-time.
Creating yarn wrapper
$ yarn wrapper <create .yarnwrapperrc file in cwd>
Where I am inspired from?
Gradle wrapper: https://docs.gradle.org/current/userguide/gradle_wrapper.html
Any chance at getting a JSON5-compatible
Project configurations would be much easier to maintain with features like comments, trailing commas, etc. There has definitely been user interest for these features (see: yarn/issues/1751 & npm/issues/3336), but the npm team rejected this request due to the personal preferences of a few members (even though the user community clearly disagrees).
I'd argue that improving the readability & maintainability of
Additionally, please consider adding an option for providing an explicit path to
The common practice of development utilities dumping their configuration & generated files into the project root is messy & obtrusive. It's fine to have that sort of thing set up as a default, but users should also have the option to maintain their project structure as they see fit.
is much easier to navigate & maintain than:
To quickly answer there are no plans at the moment to change the format of the
I'm now going to close this thread as I believe I've answered most of the questions related to the plan outlined in the first post. Feature requests should be put into their own threads.
Note that the v2 implementation is going strong on the following repository: github.com/yarnpkg/berry, and we're always happy to receive feedback (and contributions!) from early adopters.
I hope to see you there!
Hi everyone! After a year of development we've just put Yarn 2 out of beta and into stable. For more information, please read the following post: https://dev.to/arcanis/introducing-yarn-2-4eh1
This is an exciting day - thanks to everyone who helped us on our journey