feat(extensions/fetch): extend init options (#11528)

extensions/fetch/lib.rs

@@ -60,6 +60,7 @@ pub fn init<P: FetchPermissions + 'static>(
   user_agent: String,
   ca_data: Option<Vec<u8>>,
   proxy: Option<Proxy>,
+  frozen_headers: Option<HeaderMap>,
 ) -> Extension {
   Extension::builder()
     .js(include_js_files!(
@@ -89,6 +90,7 @@ pub fn init<P: FetchPermissions + 'static>(
         ca_data: ca_data.clone(),
         user_agent: user_agent.clone(),
         proxy: proxy.clone(),
+        frozen_headers: frozen_headers.clone(),
       });
       Ok(())
     })
@@ -99,6 +101,7 @@ pub struct HttpClientDefaults {
   pub user_agent: String,
   pub ca_data: Option<Vec<u8>>,
   pub proxy: Option<Proxy>,
+  pub frozen_headers: Option<HeaderMap>,
 }
 
 pub trait FetchPermissions {
@@ -214,6 +217,15 @@ where
         }
       }
 
+      // Set frozen_headers after the user provided headers, so the
+      // end user can't override them.
+      let defaults = state.borrow::<HttpClientDefaults>();
+      if let Some(frozen_headers) = &defaults.frozen_headers {
+        for (key, value) in frozen_headers {
+          request = request.header(key, value)
+        }
+      }
+
       let cancel_handle = CancelHandle::new_rc();
       let cancel_handle_ = cancel_handle.clone();
 

runtime/build.rs

@@ -46,6 +46,7 @@ fn create_runtime_snapshot(snapshot_path: &Path, files: Vec<PathBuf>) {
       "".to_owned(),
       None,
       None,
+      None,
     ),
     deno_websocket::init::<deno_websocket::NoWebSocketPermissions>(
       "".to_owned(),

runtime/web_worker.rs

@@ -301,6 +301,7 @@ impl WebWorker {
         options.user_agent.clone(),
         options.ca_data.clone(),
         None,
+        None,
       ),
       deno_websocket::init::<Permissions>(
         options.user_agent.clone(),

runtime/worker.rs

@@ -101,6 +101,7 @@ impl MainWorker {
         options.user_agent.clone(),
         options.ca_data.clone(),
         None,
+        None,
       ),
       deno_websocket::init::<Permissions>(
         options.user_agent.clone(),