software-development/developer-experience/yarn

Yarn Workspaces
Yarn is a fast, reliable, and secure package manager developed by Facebook (now Meta) in 2016. It was created to improve upon the existing package manager for JavaScript, npm (Node Package Manager), addressing some of its known issues such as slow installation speeds due to caching and network requests.
Key Features of Yarn:
  1. Speed: One of the main advantages of Yarn is its speed. It parallelizes operations to maximize resource utilization, ensuring that installations are quick and efficient.
  2. Reliability: Yarn locks down your project's dependencies in a file named yarn.lock. This ensures that every developer working on the project, as well as continuous integration servers, will install exactly the same versions of packages, reducing the risk of "it works on my machine" issues.
  3. Security: Yarn verifies package integrity using checksums and supports HTTPS for secure downloads. It also provides a feature called 'offline mirror' which allows you to install packages without an internet connection by first downloading them once online and then using this local cache.
  4. Consistency: Similar to npm, Yarn uses a package.json file to define your project dependencies, but it organizes these in a directory structure (yarn.lock). This makes it easier for teams to manage dependencies.
  5. Community and Ecosystem: Despite being developed by Facebook, Yarn is open-source and has a strong community backing. It supports the same registry as npm (npmjs.com), meaning you can use existing packages without any modification.
  6. Workspaces: Yarn has built-in support for monorepos through 'workspaces', allowing you to manage multiple related packages in a single repository, making it easier to share code and dependencies among them.
In summary, Yarn is designed to be a fast, secure, and reliable alternative to npm. It's widely used in the JavaScript community, particularly in large-scale projects and enterprise settings. However, as of 2021, npm has been adopting many of these features, blurring some of the differences between the two package managers.