Building & testing

How to build Yarn from sources and run its tests.

Installing dependencies#

Building Yarn#

Clone the ZPM repository and cd into it:

git clone https://github.com/yarnpkg/zpm.git
cd zpm

You should now be able to build the project:

cargo build --release -p zpm-switch -p zpm

We tend to build Yarn in release mode, even in development, because Rust is known to be significantly slower in debug mode. Regardless of whether you want to use the release or debug version, create a symbolic link named local pointing to the binary you just created:

ln -s target/release local

Also configure your system’s Yarn Switch to use this local version when working on the project:

yarn switch link target/release/yarn-bin

Testing Yarn#

The CLI integration tests run against the binary you just built. From the repository root, run:

cargo build -r
yarn test:integration <jest options>

For example, to run only the install command tests:

yarn test:integration commands/install.test.ts

Ecosystem end-to-end tests are shell scenarios under tests/e2e. Run them by name, without the .sh suffix:

yarn test:e2e <e2e test name>