feat(unstable): optional `deno_modules` directory (#19977)

Closes #15633

1 files changed, 38 insertions, 2 deletions

diff --git a/cli/args/mod.rs b/cli/args/mod.rs
index 68cd3faa7..9df26b063 100644
--- a/cli/args/mod.rs
+++ b/cli/args/mod.rs
@@ -539,6 +539,7 @@ pub struct CliOptions {
   flags: Flags,
   initial_cwd: PathBuf,
   maybe_node_modules_folder: Option<PathBuf>,
+  maybe_deno_modules_folder: Option<PathBuf>,
   maybe_config_file: Option<ConfigFile>,
   maybe_package_json: Option<PackageJson>,
   maybe_lockfile: Option<Arc<Mutex<Lockfile>>>,
@@ -567,13 +568,18 @@ impl CliOptions {
       eprintln!("{}", colors::yellow(msg));
     }
 
-    let maybe_node_modules_folder = resolve_local_node_modules_folder(
+    let maybe_node_modules_folder = resolve_node_modules_folder(
       &initial_cwd,
       &flags,
       maybe_config_file.as_ref(),
       maybe_package_json.as_ref(),
     )
     .with_context(|| "Resolving node_modules folder.")?;
+    let maybe_deno_modules_folder = resolve_deno_modules_folder(
+      &initial_cwd,
+      &flags,
+      maybe_config_file.as_ref(),
+    );
 
     Ok(Self {
       flags,
@@ -582,6 +588,7 @@ impl CliOptions {
       maybe_lockfile,
       maybe_package_json,
       maybe_node_modules_folder,
+      maybe_deno_modules_folder,
       overrides: Default::default(),
     })
   }
@@ -865,6 +872,10 @@ impl CliOptions {
       .map(|path| ModuleSpecifier::from_directory_path(path).unwrap())
   }
 
+  pub fn deno_modules_dir_path(&self) -> Option<&PathBuf> {
+    self.maybe_deno_modules_folder.as_ref()
+  }
+
   pub fn resolve_root_cert_store_provider(
     &self,
   ) -> Arc<dyn RootCertStoreProvider> {
@@ -1159,7 +1170,7 @@ impl CliOptions {
 }
 
 /// Resolves the path to use for a local node_modules folder.
-fn resolve_local_node_modules_folder(
+fn resolve_node_modules_folder(
   cwd: &Path,
   flags: &Flags,
   maybe_config_file: Option<&ConfigFile>,
@@ -1188,6 +1199,31 @@ fn resolve_local_node_modules_folder(
   Ok(Some(canonicalize_path_maybe_not_exists(&path)?))
 }
 
+fn resolve_deno_modules_folder(
+  cwd: &Path,
+  flags: &Flags,
+  maybe_config_file: Option<&ConfigFile>,
+) -> Option<PathBuf> {
+  let use_deno_modules_dir = flags
+    .deno_modules_dir
+    .or_else(|| maybe_config_file.and_then(|c| c.deno_modules_dir()))
+    .unwrap_or(false);
+  // Unlike the node_modules directory, there is no need to canonicalize
+  // this directory because it's just used as a cache and the resolved
+  // specifier is not based on the canonicalized path (unlike the modules
+  // in the node_modules folder).
+  if !use_deno_modules_dir {
+    None
+  } else if let Some(config_path) = maybe_config_file
+    .as_ref()
+    .and_then(|c| c.specifier.to_file_path().ok())
+  {
+    Some(config_path.parent().unwrap().join("deno_modules"))
+  } else {
+    Some(cwd.join("deno_modules"))
+  }
+}
+
 fn resolve_import_map_specifier(
   maybe_import_map_path: Option<&str>,
   maybe_config_file: Option<&ConfigFile>,