Update mock context

test/src/docmanager/mockcontext.ts

@@ -43,6 +43,8 @@ class MockContext<T extends IDocumentModel> implements IDocumentContext<T> {
 
   populated: ISignal<IDocumentContext<IDocumentModel>, void>;
 
+  disposed: ISignal<IDocumentContext<T>, void>;
+
   get id(): string {
     return '';
   }
@@ -149,3 +151,4 @@ defineSignal(MockContext.prototype, 'kernelChanged');
 defineSignal(MockContext.prototype, 'pathChanged');
 defineSignal(MockContext.prototype, 'contentsModelChanged');
 defineSignal(MockContext.prototype, 'populated');
+defineSignal(Context.prototype, 'disposed');