feat: default to TS for file extension and support ext flag in more scenarios (#25472)

Closes #11220
Currently does lint, fmt, and repl

1 files changed, 22 insertions, 0 deletions

diff --git a/cli/module_loader.rs b/cli/module_loader.rs
index 86824cd70..a81c5a0aa 100644
--- a/cli/module_loader.rs
+++ b/cli/module_loader.rs
@@ -105,11 +105,32 @@ impl ModuleLoadPreparer {
     is_dynamic: bool,
     lib: TsTypeLib,
     permissions: crate::file_fetcher::FetchPermissionsOption,
+    ext_overwrite: Option<&String>,
   ) -> Result<(), AnyError> {
     log::debug!("Preparing module load.");
     let _pb_clear_guard = self.progress_bar.clear_guard();
 
     let mut cache = self.module_graph_builder.create_fetch_cacher(permissions);
+    if let Some(ext) = ext_overwrite {
+      let maybe_content_type = match ext.as_str() {
+        "ts" => Some("text/typescript"),
+        "tsx" => Some("text/tsx"),
+        "js" => Some("text/javascript"),
+        "jsx" => Some("text/jsx"),
+        _ => None,
+      };
+      if let Some(content_type) = maybe_content_type {
+        for root in roots {
+          cache.file_header_overrides.insert(
+            root.clone(),
+            std::collections::HashMap::from([(
+              "content-type".to_string(),
+              content_type.to_string(),
+            )]),
+          );
+        }
+      }
+    }
     log::debug!("Building module graph.");
     let has_type_checked = !graph.roots.is_empty();
 
@@ -763,6 +784,7 @@ impl<TGraphContainer: ModuleGraphContainer> ModuleLoader
           is_dynamic,
           lib,
           root_permissions.into(),
+          None,
         )
         .await?;
       update_permit.commit();