4 files changed, 36 insertions, 8 deletions

diff --git a/cli/tools/repl/session.rs b/cli/tools/repl/session.rs
index e3bdac3b2..361f5abb5 100644
--- a/cli/tools/repl/session.rs
+++ b/cli/tools/repl/session.rs
@@ -92,17 +92,19 @@ impl ReplSession {
     for notification in session.notifications() {
       let method = notification.get("method").unwrap().as_str().unwrap();
       let params = notification.get("params").unwrap();
-
       if method == "Runtime.executionContextCreated" {
-        context_id = params
-          .get("context")
+        let context = params.get("context").unwrap();
+        assert!(context
+          .get("auxData")
           .unwrap()
-          .get("id")
+          .get("isDefault")
           .unwrap()
-          .as_u64()
-          .unwrap();
+          .as_bool()
+          .unwrap());
+        context_id = context.get("id").unwrap().as_u64().unwrap();
       }
     }
+    assert_ne!(context_id, 0);
 
     let mut repl_session = ReplSession {
       worker,
diff --git a/core/inspector.rs b/core/inspector.rs
index daedd291d..e3db65afe 100644
--- a/core/inspector.rs
+++ b/core/inspector.rs
@@ -150,6 +150,7 @@ impl JsRuntimeInspector {
   pub fn new(
     isolate: &mut v8::OwnedIsolate,
     context: v8::Global<v8::Context>,
+    is_main: bool,
   ) -> Rc<RefCell<Self>> {
     let scope = &mut v8::HandleScope::new(isolate);
 
@@ -183,13 +184,26 @@ impl JsRuntimeInspector {
     // Tell the inspector about the global context.
     let context = v8::Local::new(scope, context);
     let context_name = v8::inspector::StringView::from(&b"global context"[..]);
-    let aux_data = v8::inspector::StringView::from(&b""[..]);
+    // NOTE(bartlomieju): this is what Node.js does and it turns out some
+    // debuggers (like VSCode) rely on this information to disconnect after
+    // program completes
+    let aux_data = if is_main {
+      r#"{"isDefault": true}"#
+    } else {
+      r#"{"isDefault": false}"#
+    };
+    let aux_data_view = v8::inspector::StringView::from(aux_data.as_bytes());
     self_
       .v8_inspector
       .borrow_mut()
       .as_mut()
       .unwrap()
-      .context_created(context, Self::CONTEXT_GROUP_ID, context_name, aux_data);
+      .context_created(
+        context,
+        Self::CONTEXT_GROUP_ID,
+        context_name,
+        aux_data_view,
+      );
 
     // Poll the session handler so we will get notified whenever there is
     // new incoming debugger activity.
diff --git a/core/runtime.rs b/core/runtime.rs
index b1ce14883..8cb38de2f 100644
--- a/core/runtime.rs
+++ b/core/runtime.rs
@@ -88,6 +88,8 @@ pub struct JsRuntime {
   allocations: IsolateAllocations,
   extensions: Vec<Extension>,
   event_loop_middlewares: Vec<Box<OpEventLoopFn>>,
+  // Marks if this is considered the top-level runtime. Used only be inspector.
+  is_main: bool,
 }
 
 pub(crate) struct DynImportModEvaluate {
@@ -274,7 +276,13 @@ pub struct RuntimeOptions {
   /// [CompiledWasmModuleStore]. If no [CompiledWasmModuleStore] is specified,
   /// `WebAssembly.Module` objects cannot be serialized.
   pub compiled_wasm_module_store: Option<CompiledWasmModuleStore>,
+
+  /// Start inspector instance to allow debuggers to connect.
   pub inspector: bool,
+
+  /// Describe if this is the main runtime instance, used by debuggers in some
+  /// situation - like disconnecting when program finishes running.
+  pub is_main: bool,
 }
 
 #[derive(Copy, Clone, PartialEq, Eq)]
@@ -498,6 +506,7 @@ impl JsRuntime {
       Some(JsRuntimeInspector::new(
         &mut isolate,
         global_context.clone(),
+        options.is_main,
       ))
     } else {
       None
@@ -532,6 +541,7 @@ impl JsRuntime {
       extensions: options.extensions,
       state: state_rc,
       module_map: Some(module_map_rc),
+      is_main: options.is_main,
     };
 
     // Init resources and ops before extensions to make sure they are
@@ -949,6 +959,7 @@ impl JsRuntime {
     state.inspector = Some(JsRuntimeInspector::new(
       self.v8_isolate.as_mut().unwrap(),
       state.global_realm.clone().unwrap().0,
+      self.is_main,
     ));
   }
 
diff --git a/runtime/worker.rs b/runtime/worker.rs
index 0c439c703..967d53ea8 100644
--- a/runtime/worker.rs
+++ b/runtime/worker.rs
@@ -240,6 +240,7 @@ impl MainWorker {
       compiled_wasm_module_store: options.compiled_wasm_module_store.clone(),
       extensions,
       inspector: options.maybe_inspector_server.is_some(),
+      is_main: true,
       ..Default::default()
     });