Don't let the IDE throw away executionContext/executionStatus messages

app/gui/controller/engine-protocol/src/language_server/types.rs

@@ -301,8 +301,8 @@ pub enum DiagnosticType {
 #[allow(missing_docs)]
 #[serde(rename_all = "camelCase")]
 pub struct Diagnostic {
-    kind:          DiagnosticType,
-    message:       String,
+    pub kind:          DiagnosticType,
+    pub message:       String,
     path:          Option<Path>,
     location:      Option<TextRange>,
     expression_id: Option<ExpressionId>,

app/gui/src/model/project.rs

@@ -164,12 +164,17 @@ pub type Synchronized = synchronized::Project;
 // ====================
 
 /// Notification emitted by the project model.
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+#[derive(Clone, Debug, PartialEq, Eq)]
 pub enum Notification {
     /// One of the backend connections has been lost.
     ConnectionLost(BackendConnection),
     /// Indicates that the project VCS status has changed.
     VcsStatusChanged(VcsStatus),
+    /// Any message to be displayed as a notification
+    Message {
+        /// text of the message
+        message: String,
+    },
 }
 
 /// Denotes one of backend connections used by a project.

app/gui/src/model/project/synchronized.rs

@@ -18,6 +18,7 @@ use engine_protocol::language_server;
 use engine_protocol::language_server::response;
 use engine_protocol::language_server::CapabilityRegistration;
 use engine_protocol::language_server::ContentRoot;
+use engine_protocol::language_server::DiagnosticType;
 use engine_protocol::language_server::ExpressionUpdates;
 use engine_protocol::language_server::MethodPointer;
 use engine_protocol::project_manager;
@@ -493,7 +494,23 @@ impl Project {
                     let execution_update = ExecutionUpdate::ExpressionUpdates(updates);
                     execution_update_handler(context_id, execution_update);
                 }
-                Event::Notification(Notification::ExecutionStatus(_)) => {}
+                Event::Notification(Notification::ExecutionStatus(status)) => {
+                    if status.diagnostics.len() > 0 {
+                        let fst = &status.diagnostics[0];
+                        if fst.kind == DiagnosticType::Error {
+                            let notification = model::project::Notification::Message {
+                                message: fst.message.as_str().to_owned(),
+                            };
+                            publisher.notify(notification);
+                        }
+                        error!(
+                            "Evaluation failed in context {}. {:?}: {}",
+                            status.context_id,
+                            fst.kind,
+                            fst.message.as_str()
+                        );
+                    }
+                }
                 Event::Notification(Notification::ExecutionComplete { context_id }) => {
                     execution_update_handler(context_id, ExecutionUpdate::Completed);
                 }

app/gui/src/presenter/project.rs

@@ -319,6 +319,10 @@ impl Project {
                 Notification::VcsStatusChanged(VcsStatus::Clean) => {
                     model.set_project_changed(false);
                 }
+                Notification::Message { message } => {
+                    let message = view::status_bar::event::Label::from(message);
+                    model.status_bar.add_event(message);
+                }
             };
             std::future::ready(())
         });