Make an execution model for just native notebooks (#13480)

* Initial idea

* Fix build errors

* Fix outputs how VS code likes em

* Nightly submit - not working

* Fix 13509 - Update display data not being handled

* Fix test

* Code review feedback

* Fix execution count and empty cell test

* Fix up after merge

* Add some news entries

* Fix unit tests

Author: rchiodo

news/2 Fixes/13509.md

@@ -0,0 +1 @@
+Updating other cells with display.update does not work in native notebooks.

news/2 Fixes/13520.md

@@ -0,0 +1 @@
+Fix for notebook using the first kernel every time. It will now use the language in the notebook to determine the most appropriate kernel.

src/client/datascience/baseJupyterSession.ts

@@ -68,16 +68,22 @@ export abstract class BaseJupyterSession implements IJupyterSession {
     public get isConnected(): boolean {
         return this.connected;
     }
+    public get onIoPubMessage() {
+        return this.ioPubEventEmitter.event;
+    }
     protected onStatusChangedEvent: EventEmitter<ServerStatus> = new EventEmitter<ServerStatus>();
     protected statusHandler: Slot<ISessionWithSocket, Kernel.Status>;
     protected connected: boolean = false;
     protected restartSessionPromise: Promise<ISessionWithSocket | undefined> | undefined;
     private _session: ISessionWithSocket | undefined;
     private _kernelSocket = new ReplaySubject<KernelSocketInformation | undefined>();
     private _jupyterLab?: typeof import('@jupyterlab/services');
+    private ioPubEventEmitter = new EventEmitter<KernelMessage.IIOPubMessage>();
+    private ioPubHandler: Slot<ISessionWithSocket, KernelMessage.IIOPubMessage>;
 
     constructor(private restartSessionUsed: (id: Kernel.IKernelConnection) => void, public workingDirectory: string) {
         this.statusHandler = this.onStatusChanged.bind(this);
+        this.ioPubHandler = (_s, m) => this.ioPubEventEmitter.fire(m);
     }
     public dispose(): Promise<void> {
         return this.shutdown();
@@ -407,7 +413,13 @@ export abstract class BaseJupyterSession implements IJupyterSession {
     // Changes the current session.
     protected setSession(session: ISessionWithSocket | undefined) {
         const oldSession = this._session;
+        if (this.ioPubHandler && oldSession) {
+            oldSession.iopubMessage.disconnect(this.ioPubHandler);
+        }
         this._session = session;
+        if (session) {
+            session.iopubMessage.connect(this.ioPubHandler);
+        }
 
         // If we have a new session, then emit the new kernel connection information.
         if (session && oldSession !== session) {

src/client/datascience/jupyter/jupyterNotebook.ts

@@ -166,7 +166,6 @@ export class JupyterNotebookBase implements INotebook {
     public get onKernelRestarted(): Event<void> {
         return this.kernelRestarted.event;
     }
-
     public get onKernelInterrupted(): Event<void> {
         return this.kernelInterrupted.event;
     }
@@ -179,10 +178,13 @@ export class JupyterNotebookBase implements INotebook {
     public get kernelSocket(): Observable<KernelSocketInformation | undefined> {
         return this.session.kernelSocket;
     }
+    public get session(): IJupyterSession {
+        return this._session;
+    }
 
     constructor(
         _liveShare: ILiveShareApi, // This is so the liveshare mixin works
-        private session: IJupyterSession,
+        private readonly _session: IJupyterSession,
         private configService: IConfigurationService,
         private disposableRegistry: IDisposableRegistry,
         executionInfo: INotebookExecutionInfo,