Improve support of type definitions (#3755)

1 files changed, 13 insertions, 1 deletions

diff --git a/cli/ops/compiler.rs b/cli/ops/compiler.rs
index d2a2a1d58..2934c79ee 100644
--- a/cli/ops/compiler.rs
+++ b/cli/ops/compiler.rs
@@ -109,8 +109,20 @@ fn op_fetch_source_files(
     let files = try_join_all(futures).await?;
 
     // We want to get an array of futures that resolves to
-    let v = files.into_iter().map(|file| {
+    let v = files.into_iter().map(|f| {
       async {
+        // if the source file contains a `types_url` we need to replace
+        // the module with the type definition when requested by the compiler
+        let file = match f.types_url {
+          Some(types_url) => {
+            let types_specifier = ModuleSpecifier::from(types_url);
+            global_state
+              .file_fetcher
+              .fetch_source_file_async(&types_specifier, ref_specifier.clone())
+              .await?
+          }
+          _ => f,
+        };
         // Special handling of Wasm files:
         // compile them into JS first!
         // This allows TS to do correct export types.