4 files changed, 93 insertions, 16 deletions
diff --git a/cli/npm/installer.rs b/cli/npm/installer.rs
new file mode 100644
index 000000000..149126cd5
--- /dev/null
+++ b/cli/npm/installer.rs
@@ -0,0 +1,88 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+
+use std::collections::BTreeMap;
+use std::sync::atomic::AtomicBool;
+use std::sync::Arc;
+
+use deno_core::error::AnyError;
+use deno_graph::npm::NpmPackageReq;
+
+use super::NpmRegistryApi;
+use super::NpmResolution;
+
+#[derive(Debug)]
+struct PackageJsonDepsInstallerInner {
+  has_installed: AtomicBool,
+  npm_registry_api: NpmRegistryApi,
+  npm_resolution: NpmResolution,
+  package_deps: BTreeMap<String, NpmPackageReq>,
+}
+
+/// Holds and controls installing dependencies from package.json.
+#[derive(Debug, Clone, Default)]
+pub struct PackageJsonDepsInstaller(Option<Arc<PackageJsonDepsInstallerInner>>);
+
+impl PackageJsonDepsInstaller {
+  pub fn new(
+    npm_registry_api: NpmRegistryApi,
+    npm_resolution: NpmResolution,
+    deps: Option<BTreeMap<String, NpmPackageReq>>,
+  ) -> Self {
+    Self(deps.map(|package_deps| {
+      Arc::new(PackageJsonDepsInstallerInner {
+        has_installed: AtomicBool::new(false),
+        npm_registry_api,
+        npm_resolution,
+        package_deps,
+      })
+    }))
+  }
+
+  pub fn package_deps(&self) -> Option<&BTreeMap<String, NpmPackageReq>> {
+    self.0.as_ref().map(|inner| &inner.package_deps)
+  }
+
+  /// Gets if the package.json has the specified package name.
+  pub fn has_package_name(&self, name: &str) -> bool {
+    if let Some(package_deps) = self.package_deps() {
+      // ensure this looks at the package name and not the
+      // bare specifiers (do not look at the keys!)
+      package_deps.values().any(|v| v.name == name)
+    } else {
+      false
+    }
+  }
+
+  /// Installs the top level dependencies in the package.json file
+  /// without going through and resolving the descendant dependencies yet.
+  pub async fn ensure_top_level_install(&self) -> Result<(), AnyError> {
+    use std::sync::atomic::Ordering;
+    let inner = match &self.0 {
+      Some(inner) => inner,
+      None => return Ok(()),
+    };
+
+    if inner.has_installed.swap(true, Ordering::SeqCst) {
+      return Ok(()); // already installed by something else
+    }
+
+    let mut package_reqs =
+      inner.package_deps.values().cloned().collect::<Vec<_>>();
+    package_reqs.sort(); // deterministic resolution
+
+    inner
+      .npm_registry_api
+      .cache_in_parallel(
+        package_reqs.iter().map(|req| req.name.clone()).collect(),
+      )
+      .await?;
+
+    for package_req in package_reqs {
+      inner
+        .npm_resolution
+        .resolve_package_req_as_pending(&package_req)?;
+    }
+
+    Ok(())
+  }
+}
diff --git a/cli/npm/mod.rs b/cli/npm/mod.rs
index 602b4ad44..ea18f8866 100644
--- a/cli/npm/mod.rs
+++ b/cli/npm/mod.rs
@@ -1,6 +1,7 @@
 // Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
 
 mod cache;
+mod installer;
 mod registry;
 mod resolution;
 mod resolvers;
@@ -8,6 +9,7 @@ mod tarball;
 
 pub use cache::should_sync_download;
 pub use cache::NpmCache;
+pub use installer::PackageJsonDepsInstaller;
 #[cfg(test)]
 pub use registry::NpmPackageVersionDistInfo;
 pub use registry::NpmRegistryApi;
diff --git a/cli/npm/resolution/mod.rs b/cli/npm/resolution/mod.rs
index 53284d712..f43f3c5cb 100644
--- a/cli/npm/resolution/mod.rs
+++ b/cli/npm/resolution/mod.rs
@@ -404,8 +404,9 @@ impl NpmResolution {
   }
 
   /// Resolves a package requirement for deno graph. This should only be
-  /// called by deno_graph's NpmResolver.
-  pub fn resolve_package_req_for_deno_graph(
+  /// called by deno_graph's NpmResolver or for resolving packages in
+  /// a package.json
+  pub fn resolve_package_req_as_pending(
     &self,
     pkg_req: &NpmPackageReq,
   ) -> Result<NpmPackageNv, AnyError> {
diff --git a/cli/npm/resolvers/mod.rs b/cli/npm/resolvers/mod.rs
index f68eeac26..0027698c0 100644
--- a/cli/npm/resolvers/mod.rs
+++ b/cli/npm/resolvers/mod.rs
@@ -19,7 +19,6 @@ use deno_runtime::deno_node::RequireNpmResolver;
 use global::GlobalNpmPackageResolver;
 use serde::Deserialize;
 use serde::Serialize;
-use std::collections::BTreeMap;
 use std::path::Path;
 use std::path::PathBuf;
 use std::sync::Arc;
@@ -224,19 +223,6 @@ impl NpmPackageResolver {
     self.resolution.has_packages()
   }
 
-  /// Adds the package reqs from a package.json if they exist.
-  pub async fn add_package_json_deps(
-    &self,
-    maybe_package_json_deps: Option<&BTreeMap<String, NpmPackageReq>>,
-  ) -> Result<(), AnyError> {
-    if let Some(deps) = maybe_package_json_deps {
-      let mut package_reqs = deps.values().cloned().collect::<Vec<_>>();
-      package_reqs.sort(); // deterministic resolution
-      self.add_package_reqs(package_reqs).await?;
-    }
-    Ok(())
-  }
-
   /// Adds package requirements to the resolver and ensures everything is setup.
   pub async fn add_package_reqs(
     &self,