Be more careful about sessioncontext kernelChanged and sessionChanged…

… signal emisssions Fixes jupyterlab#7690
jasongrout · Dec 24, 2019 · 3048d17 · 3048d17
1 parent 023828a
commit 3048d17
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Showing 2 changed files with 12 additions and 4 deletions.
diff --git a/packages/apputils/src/sessioncontext.tsx b/packages/apputils/src/sessioncontext.tsx
@@ -766,8 +766,10 @@ export class SessionContext implements ISessionContext {
     if (this._session) {
       this._session.dispose();
     }
+    const oldValue = this._session;
     this._session = null;
-    this._terminated.emit(undefined);
+    const newValue = this._session;
+    this._sessionChanged.emit({ name: 'session', oldValue, newValue });
   }
 
   /**
@@ -873,7 +875,6 @@ export class SessionContext implements ISessionContext {
   private _initializing = false;
   private _initPromise = new PromiseDelegate<boolean>();
   private _isReady = false;
-  private _terminated = new Signal<this, void>(this);
   private _kernelChanged = new Signal<
     this,
     Session.ISessionConnection.IKernelChangedArgs

diff --git a/packages/services/src/session/default.ts b/packages/services/src/session/default.ts
@@ -206,8 +206,15 @@ export class SessionConnection implements Session.ISessionConnection {
     }
     this._isDisposed = true;
     this._disposed.emit();
-    this._kernel?.dispose();
-    this._kernel = null;
+
+    if (this._kernel) {
+      this._kernel.dispose();
+      let oldValue = this._kernel;
+      this._kernel = null;
+      let newValue = this._kernel;
+      this._kernelChanged.emit({ name: 'kernel', oldValue, newValue });
+    }
+
     Signal.clearData(this);
   }