Struct Yarn 

pub struct Yarn;

Yarn package manager adapter.

Trait Implementations

impl PackageManager for Yarn

fn name(&self) -> &'static str

Returns the name of the package manager.

fn detect(&self, project_dir: &Path) -> bool

Detects if the project uses yarn by checking for yarn.lock.

fn bloat_dirs(&self, project_dir: &Path) -> Vec<BloatDir>

Returns the bloat directories for yarn (node_modules).

fn enforce_lockfile( &self, project_dir: &Path, policy: EnforcePolicy, ) -> Result<()>

Enforces the lockfile without installing anything.

--mode update-lockfile resolves package.json and writes only yarn.lock. It is a Yarn Berry (2+) flag; Yarn Classic rejects it. Classic offers no resolve-only mode at all — its nearest equivalent, yarn install --frozen-lockfile, performs a full install and runs every dependency’s lifecycle scripts, which is not something to do as a precondition for deleting that same tree. So on Classic an existing yarn.lock is itself the proof that node_modules is rebuildable, and that is what we require.

On Berry, --immutable is what keeps the resolution read-only: it fails when yarn.lock would change rather than writing the change out.

fn restore(&self, project_dir: &Path) -> Result<()>

Restores the dependencies using the lockfile.

fn lockfiles(&self) -> &'static [&'static str]

The file this manager rebuilds its bloat directory from.