fix(npm): better error message when attempting to use typescript in npm packages (#16813)

1 files changed, 12 insertions, 7 deletions

diff --git a/cli/node/mod.rs b/cli/node/mod.rs
index 8f0f0ef6d..fc4db33ee 100644
--- a/cli/node/mod.rs
+++ b/cli/node/mod.rs
@@ -703,20 +703,25 @@ pub fn url_to_node_resolution(
   npm_resolver: &dyn RequireNpmResolver,
 ) -> Result<NodeResolution, AnyError> {
   let url_str = url.as_str().to_lowercase();
-  Ok(if url_str.starts_with("http") {
-    NodeResolution::Esm(url)
+  if url_str.starts_with("http") {
+    Ok(NodeResolution::Esm(url))
   } else if url_str.ends_with(".js") || url_str.ends_with(".d.ts") {
     let package_config = get_closest_package_json(&url, npm_resolver)?;
     if package_config.typ == "module" {
-      NodeResolution::Esm(url)
+      Ok(NodeResolution::Esm(url))
     } else {
-      NodeResolution::CommonJs(url)
+      Ok(NodeResolution::CommonJs(url))
     }
   } else if url_str.ends_with(".mjs") || url_str.ends_with(".d.mts") {
-    NodeResolution::Esm(url)
+    Ok(NodeResolution::Esm(url))
+  } else if url_str.ends_with(".ts") {
+    Err(generic_error(format!(
+      "TypeScript files are not supported in npm packages: {}",
+      url
+    )))
   } else {
-    NodeResolution::CommonJs(url)
-  })
+    Ok(NodeResolution::CommonJs(url))
+  }
 }
 
 fn finalize_resolution(