fix: honour handleTransparentWorkspaces setting in Yarn/Berry

crates/turborepo-repository/src/package_graph/builder.rs

@@ -10,8 +10,8 @@ use turborepo_graph_utils as graph;
 use turborepo_lockfiles::Lockfile;
 
 use super::{
-    dep_splitter::DependencySplitter, npmrc::NpmRc, PackageGraph, PackageInfo, PackageName,
-    PackageNode,
+    dep_splitter::DependencySplitter, npmrc::NpmRc, yarnrc::YarnRc, PackageGraph, PackageInfo,
+    PackageName, PackageNode,
 };
 use crate::{
     discovery::{
@@ -362,6 +362,17 @@ impl<'a, T: PackageDiscovery> BuildState<'a, ResolvedWorkspaces, T> {
             }
             _ => None,
         };
+        let yarnrc_path = self.repo_root.join_component(".yarnrc.yml");
+        let yarnrc = match package_manager {
+            PackageManager::Berry => {
+                // HOME?
+                match yarnrc_path.read_existing_to_string().ok().flatten() {
+                    Some(contents) => YarnRc::from_reader(contents.as_bytes()).ok(),
+                    None => None,
+                }
+            }
+            _ => None,
+        };
         let split_deps = self
             .workspaces
             .iter()
@@ -375,6 +386,7 @@ impl<'a, T: PackageDiscovery> BuildState<'a, ResolvedWorkspaces, T> {
                         &self.workspaces,
                         package_manager,
                         npmrc.as_ref(),
+                        yarnrc.as_ref(),
                         entry.package_json.all_dependencies(),
                     ),
                 )
@@ -567,6 +579,7 @@ impl Dependencies {
         workspaces: &HashMap<PackageName, PackageInfo>,
         package_manager: &PackageManager,
         npmrc: Option<&NpmRc>,
+        yarnrc: Option<&YarnRc>,
         dependencies: I,
     ) -> Self {
         let resolved_workspace_json_path = repo_root.resolve(workspace_json_path);
@@ -575,8 +588,14 @@ impl Dependencies {
             .expect("package.json path should have parent");
         let mut internal = HashSet::new();
         let mut external = BTreeMap::new();
-        let splitter =
-            DependencySplitter::new(repo_root, workspace_dir, workspaces, package_manager, npmrc);
+        let splitter = DependencySplitter::new(
+            repo_root,
+            workspace_dir,
+            workspaces,
+            package_manager,
+            npmrc,
+            yarnrc,
+        );
         for (name, version) in dependencies.into_iter() {
             if let Some(workspace) = splitter.is_internal(name, version) {
                 internal.insert(workspace);

crates/turborepo-repository/src/package_graph/dep_splitter.rs

@@ -5,7 +5,7 @@ use turbopath::{
     RelativeUnixPathBuf,
 };
 
-use super::{npmrc::NpmRc, PackageInfo, PackageName};
+use super::{npmrc::NpmRc, yarnrc::YarnRc, PackageInfo, PackageName};
 use crate::package_manager::PackageManager;
 
 pub struct DependencySplitter<'a> {
@@ -22,13 +22,15 @@ impl<'a> DependencySplitter<'a> {
         workspaces: &'a HashMap<PackageName, PackageInfo>,
         package_manager: &PackageManager,
         npmrc: Option<&'a NpmRc>,
+        yarnrc: Option<&'a YarnRc>,
     ) -> Self {
         Self {
             repo_root,
             workspace_dir,
             workspaces,
             link_workspace_packages: npmrc
                 .and_then(|npmrc| npmrc.link_workspace_packages)
+                .or_else(|| yarnrc.map(|yarnrc| yarnrc.enableTransparentWorkspaces))
                 .unwrap_or(!matches!(package_manager, PackageManager::Pnpm9)),
         }
     }

crates/turborepo-repository/src/package_graph/mod.rs

@@ -20,6 +20,7 @@ use crate::{
 pub mod builder;
 mod dep_splitter;
 mod npmrc;
+mod yarnrc;
 
 pub use builder::{Error, PackageGraphBuilder};
 

crates/turborepo-repository/src/package_graph/yarnrc.rs

@@ -0,0 +1,63 @@
+use std::io;
+
+use serde::Deserialize;
+use serde_yaml;
+
+#[derive(Debug, thiserror::Error)]
+pub enum Error {
+    #[error("encountered error parsing yarnrc.yml: {0}")]
+    SerdeYaml(#[from] serde_yaml::Error),
+}
+
+/// A yarnrc.yaml file representing settings affecting the package graph.
+#[allow(non_snake_case)]
+#[derive(Debug, PartialEq, Eq, Clone, Deserialize)]
+pub struct YarnRc {
+    /// Used by Yarn(Berry) as `enableTransparentWorkspaces`.
+    /// When true, treats local workspaces that match a package name
+    /// and semver range as correct match resulting in turbo including
+    /// the package in the dependency graph
+    pub enableTransparentWorkspaces: bool,
+}
+
+impl Default for YarnRc {
+    fn default() -> YarnRc {
+        YarnRc {
+            enableTransparentWorkspaces: true,
+        }
+    }
+}
+
+impl YarnRc {
+    pub fn from_reader(mut reader: impl io::Read) -> Result<Self, Error> {
+        let config: YarnRc = serde_yaml::from_reader(&mut reader)?;
+        Ok(config)
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn test_parse_empty_yarnrc() {
+        let empty = YarnRc::from_reader(b"".as_slice()).unwrap();
+        assert_eq!(
+            empty,
+            YarnRc {
+                enableTransparentWorkspaces: true
+            }
+        );
+    }
+
+    #[test]
+    fn test_parses_transparent_workspaces() {
+        let empty = YarnRc::from_reader(b"enableTransparentWorkspaces: false".as_slice()).unwrap();
+        assert_eq!(
+            empty,
+            YarnRc {
+                enableTransparentWorkspaces: false
+            }
+        );
+    }
+}