1 files changed, 65 insertions, 0 deletions
diff --git a/cli/npm/mod.rs b/cli/npm/mod.rs
index cc14bec0a..08c15941a 100644
--- a/cli/npm/mod.rs
+++ b/cli/npm/mod.rs
@@ -8,11 +8,19 @@ mod managed;
 use std::path::PathBuf;
 use std::sync::Arc;
 
+use dashmap::DashMap;
 use deno_ast::ModuleSpecifier;
 use deno_core::error::AnyError;
+use deno_core::serde_json;
+use deno_npm::registry::NpmPackageInfo;
 use deno_runtime::deno_node::NpmResolver;
+use deno_runtime::permissions::PermissionsContainer;
+use deno_semver::package::PackageNv;
 use deno_semver::package::PackageReq;
 
+use crate::args::npm_registry_url;
+use crate::file_fetcher::FileFetcher;
+
 pub use self::byonm::ByonmCliNpmResolver;
 pub use self::byonm::CliNpmResolverByonmCreateOptions;
 pub use self::cache_dir::NpmCacheDir;
@@ -87,3 +95,60 @@ pub trait CliNpmResolver: NpmResolver {
   /// or `None` if the state currently can't be determined.
   fn check_state_hash(&self) -> Option<u64>;
 }
+
+#[derive(Debug)]
+pub struct NpmFetchResolver {
+  nv_by_req: DashMap<PackageReq, Option<PackageNv>>,
+  info_by_name: DashMap<String, Option<Arc<NpmPackageInfo>>>,
+  file_fetcher: FileFetcher,
+}
+
+impl NpmFetchResolver {
+  pub fn new(file_fetcher: FileFetcher) -> Self {
+    Self {
+      nv_by_req: Default::default(),
+      info_by_name: Default::default(),
+      file_fetcher,
+    }
+  }
+
+  pub async fn req_to_nv(&self, req: &PackageReq) -> Option<PackageNv> {
+    if let Some(nv) = self.nv_by_req.get(req) {
+      return nv.value().clone();
+    }
+    let maybe_get_nv = || async {
+      let name = req.name.clone();
+      let package_info = self.package_info(&name).await?;
+      // Find the first matching version of the package which is cached.
+      let mut versions = package_info.versions.keys().collect::<Vec<_>>();
+      versions.sort();
+      let version = versions
+        .into_iter()
+        .rev()
+        .find(|v| req.version_req.tag().is_none() && req.version_req.matches(v))
+        .cloned()?;
+      Some(PackageNv { name, version })
+    };
+    let nv = maybe_get_nv().await;
+    self.nv_by_req.insert(req.clone(), nv.clone());
+    nv
+  }
+
+  pub async fn package_info(&self, name: &str) -> Option<Arc<NpmPackageInfo>> {
+    if let Some(info) = self.info_by_name.get(name) {
+      return info.value().clone();
+    }
+    let fetch_package_info = || async {
+      let info_url = npm_registry_url().join(name).ok()?;
+      let file = self
+        .file_fetcher
+        .fetch(&info_url, PermissionsContainer::allow_all())
+        .await
+        .ok()?;
+      serde_json::from_slice::<NpmPackageInfo>(&file.source).ok()
+    };
+    let info = fetch_package_info().await.map(Arc::new);
+    self.info_by_name.insert(name.to_string(), info.clone());
+    info
+  }
+}