feat(core): send "executionContextDestroyed" notification on program end (#16831)

This commit changes "JsRuntime" to send "executionContextDestroyed"
notification when the program finishes and shows a prompt informing 
that runtime is waiting for inspector to disconnect.

cli/tests/inspector_tests.rs

@@ -303,7 +303,6 @@ mod inspector {
       .unwrap();
 
     let msg = ws_read_msg(&mut socket).await;
-    println!("response msg 1 {}", msg);
     assert_starts_with!(msg, r#"{"id":6,"result":{"debuggerId":"#);
 
     socket
@@ -312,7 +311,6 @@ mod inspector {
       .unwrap();
 
     let msg = ws_read_msg(&mut socket).await;
-    println!("response msg 2 {}", msg);
     assert_eq!(msg, r#"{"id":31,"result":{}}"#);
 
     child.kill().unwrap();
@@ -546,6 +544,10 @@ mod inspector {
       .filter(|s| !s.starts_with("Deno "));
 
     assert_stderr_for_inspect(&mut stderr_lines);
+    assert_eq!(
+      &stdout_lines.next().unwrap(),
+      "exit using ctrl+d, ctrl+c, or close()"
+    );
 
     assert_inspector_messages(
     &mut socket_tx,
@@ -564,11 +566,6 @@ mod inspector {
   )
   .await;
 
-    assert_eq!(
-      &stdout_lines.next().unwrap(),
-      "exit using ctrl+d, ctrl+c, or close()"
-    );
-
     assert_inspector_messages(
     &mut socket_tx,
     &[
@@ -577,7 +574,6 @@ mod inspector {
     &mut socket_rx,
     &[r#"{"id":3,"result":{}}"#], &[]
   ).await;
-
     assert_inspector_messages(
     &mut socket_tx,
     &[
@@ -587,7 +583,6 @@ mod inspector {
     &[r#"{"id":4,"result":{"result":{"type":"string","value":""#],
     &[],
   ).await;
-
     assert_inspector_messages(
     &mut socket_tx,
     &[
@@ -597,9 +592,7 @@ mod inspector {
     &[r#"{"id":5,"result":{"result":{"type":"undefined"}}}"#],
     &[r#"{"method":"Runtime.consoleAPICalled"#],
   ).await;
-
     assert_eq!(&stderr_lines.next().unwrap(), "done");
-
     drop(stdin);
     child.wait().unwrap();
   }
@@ -905,6 +898,26 @@ mod inspector {
     assert_eq!(&stdout_lines.next().unwrap(), "hello");
     assert_eq!(&stdout_lines.next().unwrap(), "world");
 
+    assert_inspector_messages(
+      &mut socket_tx,
+      &[],
+      &mut socket_rx,
+      &[],
+      &[
+        r#"{"method":"Debugger.resumed","params":{}}"#,
+        r#"{"method":"Runtime.consoleAPICalled","#,
+        r#"{"method":"Runtime.consoleAPICalled","#,
+        r#"{"method":"Runtime.executionContextDestroyed","params":{"executionContextId":1}}"#,
+      ],
+    )
+    .await;
+    let line = &stdout_lines.next().unwrap();
+
+    assert_eq!(
+      line,
+      "Program finished. Waiting for inspector to disconnect to exit the process..."
+    );
+
     child.kill().unwrap();
     child.wait().unwrap();
   }

core/inspector.rs

@@ -35,6 +35,7 @@ use std::ptr::NonNull;
 use std::rc::Rc;
 use std::sync::Arc;
 use std::thread;
+use v8::HandleScope;
 
 pub enum InspectorMsgKind {
   Notification,
@@ -213,10 +214,28 @@ impl JsRuntimeInspector {
     self__
   }
 
+  pub fn context_destroyed(
+    &mut self,
+    scope: &mut HandleScope,
+    context: v8::Global<v8::Context>,
+  ) {
+    let context = v8::Local::new(scope, context);
+    self
+      .v8_inspector
+      .borrow_mut()
+      .as_mut()
+      .unwrap()
+      .context_destroyed(context);
+  }
+
   pub fn has_active_sessions(&self) -> bool {
     self.sessions.borrow().has_active_sessions()
   }
 
+  pub fn has_blocking_sessions(&self) -> bool {
+    self.sessions.borrow().has_blocking_sessions()
+  }
+
   fn poll_sessions(
     &self,
     mut invoker_cx: Option<&mut Context>,
@@ -262,8 +281,11 @@ impl JsRuntimeInspector {
         // Accept new connections.
         let poll_result = sessions.session_rx.poll_next_unpin(cx);
         if let Poll::Ready(Some(session_proxy)) = poll_result {
-          let session =
-            InspectorSession::new(sessions.v8_inspector.clone(), session_proxy);
+          let session = InspectorSession::new(
+            sessions.v8_inspector.clone(),
+            session_proxy,
+            false,
+          );
           let prev = sessions.handshake.replace(session);
           assert!(prev.is_none());
         }
@@ -378,7 +400,7 @@ impl JsRuntimeInspector {
     // InspectorSessions for a local session is added directly to the "established"
     // sessions, so it doesn't need to go through the session sender.
     let inspector_session =
-      InspectorSession::new(self.v8_inspector.clone(), proxy);
+      InspectorSession::new(self.v8_inspector.clone(), proxy, true);
     self
       .sessions
       .borrow_mut()
@@ -432,6 +454,10 @@ impl SessionContainer {
     !self.established.is_empty() || self.handshake.is_some()
   }
 
+  fn has_blocking_sessions(&self) -> bool {
+    self.established.iter().any(|s| s.blocking)
+  }
+
   /// A temporary placeholder that should be used before actual
   /// instance of V8Inspector is created. It's used in favor
   /// of `Default` implementation to signal that it's not meant
@@ -528,6 +554,9 @@ struct InspectorSession {
   v8_channel: v8::inspector::ChannelBase,
   v8_session: v8::UniqueRef<v8::inspector::V8InspectorSession>,
   proxy: InspectorSessionProxy,
+  // Describes if session should keep event loop alive, eg. a local REPL
+  // session should keep event loop alive, but a Websocket session shouldn't.
+  blocking: bool,
 }
 
 impl InspectorSession {
@@ -536,6 +565,7 @@ impl InspectorSession {
   pub fn new(
     v8_inspector_rc: Rc<RefCell<v8::UniquePtr<v8::inspector::V8Inspector>>>,
     session_proxy: InspectorSessionProxy,
+    blocking: bool,
   ) -> Box<Self> {
     new_box_with(move |self_ptr| {
       let v8_channel = v8::inspector::ChannelBase::new::<Self>();
@@ -556,6 +586,7 @@ impl InspectorSession {
         v8_channel,
         v8_session,
         proxy: session_proxy,
+        blocking,
       }
     })
   }

core/runtime.rs

@@ -1099,9 +1099,21 @@ impl JsRuntime {
     let pending_state = self.event_loop_pending_state();
     if !pending_state.is_pending() && !maybe_scheduling {
       if has_inspector {
-        let inspector_has_active_sessions =
-          self.inspector().borrow_mut().has_active_sessions();
-        if wait_for_inspector && inspector_has_active_sessions {
+        let inspector = self.inspector();
+        let has_active_sessions = inspector.borrow().has_active_sessions();
+        let has_blocking_sessions = inspector.borrow().has_blocking_sessions();
+
+        if wait_for_inspector && has_active_sessions {
+          // If there are no blocking sessions (eg. REPL) we can now notify
+          // debugger that the program has finished running and we're ready
+          // to exit the process once debugger disconnects.
+          if !has_blocking_sessions {
+            let context = self.global_context();
+            let scope = &mut self.handle_scope();
+            inspector.borrow_mut().context_destroyed(scope, context);
+            println!("Program finished. Waiting for inspector to disconnect to exit the process...");
+          }
+
           return Poll::Pending;
         }
       }