Notebooks: Fix strict compile errors (#12591)

* strict compile for sqlSessionManager.ts

* start clientSession.ts fixes

* strict compile for clientSession.ts

* strict compile for notebookModel.ts

* add display name

* clean up code

* clean up code

* initialize string to empty string

* address PR comments

* address PR comments

* address PR comments

* remove errorMessage check

extensions/integration-tests/src/test/notebook.util.ts

@@ -24,9 +24,9 @@ export const pySparkNotebookContent: azdata.nb.INotebookContents = {
 		execution_count: 1
 	}],
 	metadata: {
-		'kernelspec': {
+		kernelspec: {
-			'name': 'pysparkkernel',
+			name: 'pysparkkernel',
-			'display_name': 'PySpark'
+			display_name: 'PySpark'
 		}
 	},
 	nbformat: 4,
@@ -41,8 +41,9 @@ export const notebookContentForCellLanguageTest: azdata.nb.INotebookContents = {
 		execution_count: 1
 	}],
 	metadata: {
-		'kernelspec': {
+		kernelspec: {
-			'name': ''
+			name: '',
+			display_name: ''
 		},
 	},
 	nbformat: 4,
@@ -72,9 +73,9 @@ export const pythonNotebookMultipleCellsContent: azdata.nb.INotebookContents = {
 		execution_count: 1
 	}],
 	metadata: {
-		'kernelspec': {
+		kernelspec: {
-			'name': 'python3',
+			name: 'python3',
-			'display_name': 'Python 3'
+			display_name: 'Python 3'
 		}
 	},
 	nbformat: 4,
@@ -89,9 +90,9 @@ export const sqlNotebookContent: azdata.nb.INotebookContents = {
 		execution_count: 1
 	}],
 	metadata: {
-		'kernelspec': {
+		kernelspec: {
-			'name': 'SQL',
+			name: 'SQL',
-			'display_name': 'SQL'
+			display_name: 'SQL'
 		}
 	},
 	nbformat: 4,
@@ -116,9 +117,9 @@ export const sqlNotebookMultipleCellsContent: azdata.nb.INotebookContents = {
 		execution_count: 1
 	}],
 	metadata: {
-		'kernelspec': {
+		kernelspec: {
-			'name': 'SQL',
+			name: 'SQL',
-			'display_name': 'SQL'
+			display_name: 'SQL'
 		}
 	},
 	nbformat: 4,
@@ -126,9 +127,9 @@ export const sqlNotebookMultipleCellsContent: azdata.nb.INotebookContents = {
 };
 
 export const pySparkKernelMetadata = {
-	'kernelspec': {
+	kernelspec: {
-		'name': 'pysparkkernel',
+		name: 'pysparkkernel',
-		'display_name': 'PySpark'
+		display_name: 'PySpark'
 	}
 };
 
@@ -138,9 +139,9 @@ export const pySparkKernelSpec = {
 };
 
 export const sqlKernelMetadata = {
-	'kernelspec': {
+	kernelspec: {
-		'name': 'SQL',
+		name: 'SQL',
-		'display_name': 'SQL'
+		display_name: 'SQL'
 	}
 };
 
@@ -150,9 +151,9 @@ export const sqlKernelSpec: azdata.nb.IKernelSpec = {
 };
 
 export const pythonKernelMetadata = {
-	'kernelspec': {
+	kernelspec: {
-		'name': 'python3',
+		name: 'python3',
-		'display_name': 'Python 3'
+		display_name: 'Python 3'
 	}
 };
 

extensions/notebook/src/test/model/sessionManager.test.ts

@@ -186,7 +186,8 @@ describe('Jupyter Session', function (): void {
 
 		// When I call changeKernel on the wrapper
 		let kernel = await session.changeKernel({
-			name: 'python'
+			name: 'python',
+			display_name: 'Python'
 		});
 		// Then I expect it to have the ID, and only be called once
 		should(kernel.id).equal('id');

src/sql/azdata.d.ts

@@ -4653,11 +4653,14 @@ declare module 'azdata' {
 		}
 
 		export interface INotebookMetadata {
-			kernelspec: IKernelInfo;
+			kernelspec?: IKernelInfo | IKernelSpec;
 			language_info?: ILanguageInfo;
 			tags?: string[];
 		}
 
+		/**
+		* @deprecated Use IKernelSpec instead
+		*/
 		export interface IKernelInfo {
 			name: string;
 			language?: string;
@@ -5059,8 +5062,8 @@ declare module 'azdata' {
 		 * An arguments object for the kernel changed event.
 		 */
 		export interface IKernelChangedArgs {
-			oldValue: IKernel | null;
+			oldValue: IKernel | undefined;
-			newValue: IKernel | null;
+			newValue: IKernel | undefined;
 		}
 
 		/// -------- JSON objects, and objects primarily intended not to have methods -----------
@@ -5088,7 +5091,7 @@ declare module 'azdata' {
 			/**
 			 * The original outgoing message.
 			 */
-			readonly msg: IMessage;
+			readonly msg: IMessage | undefined;
 
 			/**
 			 * A Thenable that resolves when the future is done.
@@ -5183,7 +5186,7 @@ declare module 'azdata' {
 		 */
 		export interface IExecuteReply {
 			status: 'ok' | 'error' | 'abort';
-			execution_count: number | null;
+			execution_count: number | null | undefined;
 		}
 
 		/**
@@ -5199,11 +5202,11 @@ declare module 'azdata' {
 		 * **See also:** [[IMessage]]
 		 */
 		export interface IHeader {
-			username: string;
-			version: string;
-			session: string;
-			msg_id: string;
 			msg_type: string;
+			username?: string;
+			version?: string;
+			session?: string;
+			msg_id?: string;
 		}
 
 		/**
@@ -5211,10 +5214,10 @@ declare module 'azdata' {
 		 */
 		export interface IMessage {
 			type: Channel;
-			header: IHeader;
-			parent_header: IHeader | {};
-			metadata: {};
 			content: any;
+			header?: IHeader;
+			parent_header?: IHeader | {};
+			metadata?: {};
 		}
 
 		/**

src/sql/workbench/api/common/sqlExtHost.protocol.ts

@@ -936,7 +936,7 @@ export interface MainThreadNotebookDocumentsAndEditorsShape extends IDisposable
 	$runAllCells(id: string, startCellUri?: UriComponents, endCellUri?: UriComponents): Promise<boolean>;
 	$clearOutput(id: string, cellUri: UriComponents): Promise<boolean>;
 	$clearAllOutputs(id: string): Promise<boolean>;
-	$changeKernel(id: string, kernel: azdata.nb.IKernelInfo): Promise<boolean>;
+	$changeKernel(id: string, kernel: azdata.nb.IKernelSpec): Promise<boolean>;
 	$registerNavigationProvider(providerId: string, handle: number);
 }
 

src/sql/workbench/contrib/notebook/test/browser/cellToolbarActions.test.ts

@@ -188,7 +188,8 @@ export async function createandLoadNotebookModel(codeContent?: nb.INotebookConte
 		metadata: {
 			kernelspec: {
 				name: 'python',
-				language: 'python'
+				language: 'python',
+				display_name: 'Python 3'
 			}
 		},
 		nbformat: 4,

src/sql/workbench/contrib/notebook/test/electron-browser/clientSession.test.ts

@@ -49,7 +49,7 @@ suite('Client Session', function (): void {
 		assert(!session.isReady);
 		assert.equal(session.status, 'starting');
 		assert(!session.isInErrorState);
-		assert(isUndefinedOrNull(session.errorMessage));
+		assert.equal(session.errorMessage, '');
 	});
 
 	test('Should call on serverManager startup if set', async function (): Promise<void> {

src/sql/workbench/contrib/notebook/test/electron-browser/contentManagers.test.ts

@@ -27,7 +27,8 @@ let expectedNotebookContent: nb.INotebookContents = {
 	metadata: {
 		kernelspec: {
 			name: 'mssql',
-			language: 'sql'
+			language: 'sql',
+			display_name: 'SQL'
 		}
 	},
 	nbformat: 4,
@@ -117,7 +118,8 @@ suite('Local Content Manager', function (): void {
 			metadata: {
 				kernelspec: {
 					name: 'mssql',
-					language: 'sql'
+					language: 'sql',
+					display_name: 'SQL'
 				}
 			},
 			nbformat: 4,
@@ -158,7 +160,8 @@ suite('Local Content Manager', function (): void {
 			metadata: {
 				kernelspec: {
 					name: 'mssql',
-					language: 'sql'
+					language: 'sql',
+					display_name: 'SQL'
 				}
 			},
 			nbformat: 4,
@@ -191,7 +194,8 @@ suite('Local Content Manager', function (): void {
 			metadata: {
 				kernelspec: {
 					name: 'Python 3',
-					language: 'python3'
+					language: 'python3',
+					display_name: 'Python 3'
 				}
 			},
 			nbformat: 4,

src/sql/workbench/contrib/notebook/test/electron-browser/notebookFindModel.test.ts

@@ -46,7 +46,8 @@ let expectedNotebookContent: nb.INotebookContents = {
 	metadata: {
 		kernelspec: {
 			name: 'mssql',
-			language: 'sql'
+			language: 'sql',
+			display_name: 'SQL'
 		}
 	},
 	nbformat: 4,
@@ -184,7 +185,8 @@ suite('Notebook Find Model', function (): void {
 			metadata: {
 				kernelspec: {
 					name: 'mssql',
-					language: 'sql'
+					language: 'sql',
+					display_name: 'SQL'
 				}
 			},
 			nbformat: 4,
@@ -216,7 +218,8 @@ suite('Notebook Find Model', function (): void {
 			metadata: {
 				kernelspec: {
 					name: 'python',
-					language: 'python'
+					language: 'python',
+					display_name: 'Python'
 				}
 			},
 			nbformat: 4,
@@ -241,7 +244,8 @@ suite('Notebook Find Model', function (): void {
 			metadata: {
 				kernelspec: {
 					name: 'python',
-					language: 'python'
+					language: 'python',
+					display_name: 'Python'
 				}
 			},
 			nbformat: 4,
@@ -301,7 +305,8 @@ suite('Notebook Find Model', function (): void {
 			metadata: {
 				kernelspec: {
 					name: 'python',
-					language: 'python'
+					language: 'python',
+					display_name: 'Python'
 				}
 			},
 			nbformat: 4,
@@ -333,7 +338,8 @@ suite('Notebook Find Model', function (): void {
 			metadata: {
 				kernelspec: {
 					name: 'python',
-					language: 'python'
+					language: 'python',
+					display_name: 'Python'
 				}
 			},
 			nbformat: 4,
@@ -364,7 +370,8 @@ suite('Notebook Find Model', function (): void {
 			metadata: {
 				kernelspec: {
 					name: 'mssql',
-					language: 'sql'
+					language: 'sql',
+					display_name: 'SQL'
 				}
 			},
 			nbformat: 4,

src/sql/workbench/contrib/notebook/test/electron-browser/notebookModel.test.ts

@@ -52,7 +52,8 @@ let expectedNotebookContent: nb.INotebookContents = {
 	metadata: {
 		kernelspec: {
 			name: 'mssql',
-			language: 'sql'
+			language: 'sql',
+			display_name: 'SQL'
 		}
 	},
 	nbformat: 4,
@@ -69,7 +70,8 @@ let expectedNotebookContentOneCell: nb.INotebookContents = {
 	metadata: {
 		kernelspec: {
 			name: 'mssql',
-			language: 'sql'
+			language: 'sql',
+			display_name: 'SQL'
 		}
 	},
 	nbformat: 4,
@@ -140,7 +142,8 @@ suite('notebook model', function (): void {
 			metadata: {
 				kernelspec: {
 					name: 'mssql',
-					language: 'sql'
+					language: 'sql',
+					display_name: 'SQL'
 				}
 			},
 			nbformat: 4,

src/sql/workbench/contrib/notebook/test/stubs.ts

@@ -52,7 +52,7 @@ export class NotebookModelStub implements INotebookModel {
 	get kernelChanged(): vsEvent.Event<nb.IKernelChangedArgs> {
 		throw new Error('method not implemented.');
 	}
-	get kernelsChanged(): vsEvent.Event<nb.IKernelSpec> {
+	get kernelsChanged(): vsEvent.Event<nb.IKernel> {
 		throw new Error('method not implemented.');
 	}
 	get layoutChanged(): vsEvent.Event<void> {

src/sql/workbench/services/notebook/browser/models/cell.ts

@@ -475,14 +475,12 @@ export class CellModel extends Disposable implements ICellModel {
 			await clientSession.kernelChangeCompleted;
 		}
 		if (!clientSession.kernel) {
-			let defaultKernel = model && model.defaultKernel && model.defaultKernel.name;
+			let defaultKernel = model && model.defaultKernel;
 			if (!defaultKernel) {
 				this.sendNotification(notificationService, Severity.Error, localize('noDefaultKernel', "No kernel is available for this notebook"));
 				return undefined;
 			}
-			await clientSession.changeKernel({
+			await clientSession.changeKernel(defaultKernel);
-				name: defaultKernel
-			});
 		}
 		return clientSession.kernel;
 	}

src/sql/workbench/services/notebook/browser/models/clientSession.ts

@@ -30,22 +30,22 @@ export class ClientSession implements IClientSession {
 	private _unhandledMessageEmitter = new Emitter<nb.IMessage>();
 	private _propertyChangedEmitter = new Emitter<'path' | 'name' | 'type'>();
 	private _notebookUri: URI;
-	private _type: string;
+	private _type: string = '';
-	private _name: string;
+	private _name: string = '';
 	private _isReady: boolean;
 	private _ready: Deferred<void>;
 	private _kernelChangeCompleted: Deferred<void>;
-	private _kernelDisplayName: string;
+	private _kernelDisplayName: string = '';
-	private _errorMessage: string;
+	private _errorMessage: string = '';
-	private _cachedKernelSpec: nb.IKernelSpec;
+	private _cachedKernelSpec: nb.IKernelSpec | undefined;
 	private _kernelChangeHandlers: KernelChangeHandler[] = [];
 	private _defaultKernel: nb.IKernelSpec;
 
 	//#endregion
 
-	private _serverLoadFinished: Promise<void>;
+	private _serverLoadFinished: Promise<void> = Promise.resolve();
-	private _session: nb.ISession;
+	private _session: nb.ISession | undefined;
-	private isServerStarted: boolean;
+	private isServerStarted: boolean = false;
 	private notebookManager: INotebookManager;
 	private _kernelConfigActions: ((kernelName: string) => Promise<any>)[] = [];
 	private _connectionId: string = '';
@@ -72,7 +72,7 @@ export class ClientSession implements IClientSession {
 		this._isReady = true;
 		this._ready.resolve();
 		if (!this.isInErrorState && this._session && this._session.kernel) {
-			await this.notifyKernelChanged(undefined, this._session.kernel);
+			await this.notifyKernelChanged(this._session.kernel);
 		}
 	}
 
@@ -173,7 +173,7 @@ export class ClientSession implements IClientSession {
 	public get propertyChanged(): Event<'path' | 'name' | 'type'> {
 		return this._propertyChangedEmitter.event;
 	}
-	public get kernel(): nb.IKernel | null {
+	public get kernel(): nb.IKernel | undefined {
 		return this._session ? this._session.kernel : undefined;
 	}
 	public get notebookUri(): URI {
@@ -210,7 +210,7 @@ export class ClientSession implements IClientSession {
 		return !!this._errorMessage;
 	}
 
-	public get cachedKernelSpec(): nb.IKernelSpec {
+	public get cachedKernelSpec(): nb.IKernelSpec | undefined {
 		return this._cachedKernelSpec;
 	}
 	//#endregion
@@ -219,29 +219,31 @@ export class ClientSession implements IClientSession {
 	/**
 	 * Change the current kernel associated with the document.
 	 */
-	async changeKernel(options: nb.IKernelSpec, oldValue?: nb.IKernel): Promise<nb.IKernel> {
+	async changeKernel(options: nb.IKernelSpec, oldValue?: nb.IKernel): Promise<nb.IKernel | undefined> {
 		this._kernelChangeCompleted = new Deferred<void>();
 		this._isReady = false;
 		let oldKernel = oldValue ? oldValue : this.kernel;
 
 		let kernel = await this.doChangeKernel(options);
 		try {
-			await kernel.ready;
+			await kernel?.ready;
 		} catch (error) {
 			// Cleanup some state before re-throwing
-			this._isReady = kernel.isReady;
+			this._isReady = kernel ? kernel.isReady : false;
 			this._kernelChangeCompleted.resolve();
 			throw error;
 		}
-		let newKernel = this._session ? kernel : this._session.kernel;
+		let newKernel = this._session ? this._session.kernel : kernel;
-		this._isReady = kernel.isReady;
+		this._isReady = kernel ? kernel.isReady : false;
 		await this.updateCachedKernelSpec();
 		// Send resolution events to listeners
-		await this.notifyKernelChanged(oldKernel, newKernel);
+		if (newKernel) {
+			await this.notifyKernelChanged(newKernel, oldKernel);
+		}
 		return kernel;
 	}
 
-	private async notifyKernelChanged(oldKernel: nb.IKernel, newKernel: nb.IKernel): Promise<void> {
+	private async notifyKernelChanged(newKernel: nb.IKernel, oldKernel?: nb.IKernel): Promise<void> {
 		let changeArgs: nb.IKernelChangedArgs = {
 			oldValue: oldKernel,
 			newValue: newKernel
@@ -267,8 +269,8 @@ export class ClientSession implements IClientSession {
 	/**
 	 * Helper method to either call ChangeKernel on current session, or start a new session
 	 */
-	private async doChangeKernel(options: nb.IKernelSpec): Promise<nb.IKernel> {
+	private async doChangeKernel(options: nb.IKernelSpec): Promise<nb.IKernel | undefined> {
-		let kernel: nb.IKernel;
+		let kernel: nb.IKernel | undefined;
 		if (this._session) {
 			kernel = await this._session.changeKernel(options);
 			await this.runKernelConfigActions(kernel.name);
@@ -289,7 +291,7 @@ export class ClientSession implements IClientSession {
 			// TODO is there any case where skipping causes errors? So far it seems like it gets called twice
 			return;
 		}
-		if (connection.id !== '-1' && connection.id !== this._connectionId) {
+		if (connection.id !== '-1' && connection.id !== this._connectionId && this._session) {
 			await this._session.configureConnection(connection);
 			this._connectionId = connection.id;
 		}

src/sql/workbench/services/notebook/browser/models/modelInterfaces.ts

@@ -82,7 +82,7 @@ export interface IClientSession extends IDisposable {
 	/**
 	 * The current kernel associated with the document.
 	 */
-	readonly kernel: nb.IKernel | null;
+	readonly kernel: nb.IKernel | undefined;
 
 	/**
 	 * The current path associated with the client session.
@@ -133,7 +133,7 @@ export interface IClientSession extends IDisposable {
 	 */
 	readonly kernelDisplayName: string;
 
-	readonly cachedKernelSpec: nb.IKernelSpec;
+	readonly cachedKernelSpec: nb.IKernelSpec | undefined;
 
 	/**
 	 * Initializes the ClientSession, by starting the server and
@@ -149,7 +149,7 @@ export interface IClientSession extends IDisposable {
 	changeKernel(
 		options: nb.IKernelSpec,
 		oldKernel?: nb.IKernel
-	): Promise<nb.IKernel>;
+	): Promise<nb.IKernel | undefined>;
 
 	/**
 	 * Configure the current kernel associated with the document.
@@ -222,7 +222,7 @@ export interface INotebookModel {
 	/**
 	 * Cell List for this model
 	 */
-	readonly cells: ReadonlyArray<ICellModel>;
+	readonly cells: ReadonlyArray<ICellModel> | undefined;
 
 	/**
 	 * The active cell for this model. May be undefined
@@ -232,7 +232,7 @@ export interface INotebookModel {
 	/**
 	 * Client Session in the notebook, used for sending requests to the notebook service
 	 */
-	readonly clientSession: IClientSession;
+	readonly clientSession: IClientSession | undefined;
 	/**
 	 * Promise indicating when client session is ready to use.
 	 */
@@ -244,7 +244,7 @@ export interface INotebookModel {
 	/**
 	 * LanguageInfo saved in the notebook
 	 */
-	readonly languageInfo: nb.ILanguageInfo;
+	readonly languageInfo: nb.ILanguageInfo | undefined;
 	/**
 	 * Current default language for the notebook
 	 */
@@ -270,7 +270,7 @@ export interface INotebookModel {
 	 * Event fired on first initialization of the kernels and
 	 * on subsequent change events
 	 */
-	readonly kernelsChanged: Event<nb.IKernelSpec>;
+	readonly kernelsChanged: Event<nb.IKernel>;
 
 	/**
 	 * Default kernel
@@ -314,7 +314,7 @@ export interface INotebookModel {
 	/**
 	 * Event fired on active cell change
 	 */
-	readonly onActiveCellChanged: Event<ICellModel>;
+	readonly onActiveCellChanged: Event<ICellModel | undefined>;
 
 	/**
 	 * Event fired on cell type change
@@ -389,7 +389,7 @@ export interface INotebookModel {
 	 * Get the standardKernelWithProvider by name
 	 * @param name The kernel name
 	 */
-	getStandardKernelFromName(name: string): IStandardKernelWithProvider;
+	getStandardKernelFromName(name: string): IStandardKernelWithProvider | undefined;
 
 	/** Event fired once we get call back from ConfigureConnection method in sqlops extension */
 	readonly onValidConnectionSelected: Event<boolean>;

src/sql/workbench/services/notebook/browser/models/notebookModel.ts

@@ -49,43 +49,43 @@ export class NotebookModel extends Disposable implements INotebookModel {
 	private _contextsChangedEmitter = new Emitter<void>();
 	private _contextsLoadingEmitter = new Emitter<void>();
 	private _contentChangedEmitter = new Emitter<NotebookContentChange>();
-	private _kernelsChangedEmitter = new Emitter<nb.IKernelSpec>();
+	private _kernelsChangedEmitter = new Emitter<nb.IKernel>();
 	private _kernelChangedEmitter = new Emitter<nb.IKernelChangedArgs>();
 	private _layoutChanged = new Emitter<void>();
 	private _inErrorState: boolean = false;
-	private _activeClientSession: IClientSession;
+	private _activeClientSession: IClientSession | undefined;
 	private _sessionLoadFinished = new Deferred<void>();
 	private _onClientSessionReady = new Emitter<IClientSession>();
 	private _onProviderIdChanged = new Emitter<string>();
 	private _trustedMode: boolean;
-	private _onActiveCellChanged = new Emitter<ICellModel>();
+	private _onActiveCellChanged = new Emitter<ICellModel | undefined>();
 	private _onCellTypeChanged = new Emitter<ICellModel>();
 
-	private _cells: ICellModel[];
+	private _cells: ICellModel[] | undefined;
-	private _defaultLanguageInfo: nb.ILanguageInfo;
+	private _defaultLanguageInfo: nb.ILanguageInfo | undefined;
-	private _tags: string[];
+	private _tags: string[] | undefined;
-	private _existingMetadata = {};
+	private _existingMetadata: nb.INotebookMetadata = {};
-	private _language: string;
+	private _language: string = '';
 	private _onErrorEmitter = new Emitter<INotification>();
-	private _savedKernelInfo: nb.IKernelInfo;
+	private _savedKernelInfo: nb.IKernelSpec | undefined;
 	private readonly _nbformat: number = nbversion.MAJOR_VERSION;
 	private readonly _nbformatMinor: number = nbversion.MINOR_VERSION;
-	private _activeConnection: ConnectionProfile;
+	private _activeConnection: ConnectionProfile | undefined;
-	private _activeCell: ICellModel;
+	private _activeCell: ICellModel | undefined;
 	private _providerId: string;
 	private _defaultKernel: nb.IKernelSpec;
 	private _kernelDisplayNameToConnectionProviderIds: Map<string, string[]> = new Map<string, string[]>();
 	private _kernelDisplayNameToNotebookProviderIds: Map<string, string> = new Map<string, string>();
 	private _onValidConnectionSelected = new Emitter<boolean>();
-	private _oldKernel: nb.IKernel;
+	private _oldKernel: nb.IKernel | undefined;
 	private _connectionUrisToDispose: string[] = [];
 	private _textCellsLoading: number = 0;
-	private _standardKernels: notebookUtils.IStandardKernelWithProvider[];
+	private _standardKernels: notebookUtils.IStandardKernelWithProvider[] = [];
 	private _kernelAliases: string[] = [];
-	private _currentKernelAlias: string;
+	private _currentKernelAlias: string | undefined;
-	private _selectedKernelDisplayName: string;
+	private _selectedKernelDisplayName: string | undefined;
 
-	public requestConnectionHandler: () => Promise<boolean>;
+	public requestConnectionHandler: (() => Promise<boolean>) | undefined;
 
 	constructor(
 		private _notebookOptions: INotebookModelOptions,
@@ -117,7 +117,7 @@ export class NotebookModel extends Disposable implements INotebookModel {
 		return notebookManagers;
 	}
 
-	public get notebookManager(): INotebookManager {
+	public get notebookManager(): INotebookManager | undefined {
 		let manager = this.notebookManagers.find(manager => manager.providerId === this._providerId);
 		if (!manager) {
 			// Note: this seems like a less than ideal scenario. We should ideally pass in the "correct" provider ID and allow there to be a default,
@@ -127,7 +127,7 @@ export class NotebookModel extends Disposable implements INotebookModel {
 		return manager;
 	}
 
-	public getNotebookManager(providerId: string): INotebookManager {
+	public getNotebookManager(providerId: string): INotebookManager | undefined {
 		if (providerId) {
 			return this.notebookManagers.find(manager => manager.providerId === providerId);
 		}
@@ -147,7 +147,7 @@ export class NotebookModel extends Disposable implements INotebookModel {
 
 	public get hasServerManager(): boolean {
 		// If the service has a server manager, then we can show the start button
-		return !!this.notebookManager.serverManager;
+		return !!this.notebookManager?.serverManager;
 	}
 
 	public get contentChanged(): Event<NotebookContentChange> {
@@ -163,7 +163,7 @@ export class NotebookModel extends Disposable implements INotebookModel {
 	 * plus startup of the session manager which can return key metadata about the
 	 * notebook environment
 	 */
-	public get clientSession(): IClientSession {
+	public get clientSession(): IClientSession | undefined {
 		return this._activeClientSession;
 	}
 
@@ -171,7 +171,7 @@ export class NotebookModel extends Disposable implements INotebookModel {
 		return this._kernelChangedEmitter.event;
 	}
 
-	public get kernelsChanged(): Event<nb.IKernelSpec> {
+	public get kernelsChanged(): Event<nb.IKernel> {
 		return this._kernelsChangedEmitter.event;
 	}
 
@@ -191,17 +191,17 @@ export class NotebookModel extends Disposable implements INotebookModel {
 		return this._contextsLoadingEmitter.event;
 	}
 
-	public get cells(): ICellModel[] {
+	public get cells(): ICellModel[] | undefined {
 		return this._cells;
 	}
 
-	public get context(): ConnectionProfile {
+	public get context(): ConnectionProfile | undefined {
 		return this._activeConnection;
 	}
 
 	public get specs(): nb.IAllKernels | undefined {
 		let specs: nb.IAllKernels = {
-			defaultKernel: undefined,
+			defaultKernel: '',
 			kernels: []
 		};
 		this.notebookManagers.forEach(manager => {
@@ -241,11 +241,11 @@ export class NotebookModel extends Disposable implements INotebookModel {
 		return this._kernelAliases;
 	}
 
-	public get currentKernelAlias(): string {
+	public get currentKernelAlias(): string | undefined {
 		return this._currentKernelAlias;
 	}
 
-	public get selectedKernelDisplayName(): string {
+	public get selectedKernelDisplayName(): string | undefined {
 		return this._selectedKernelDisplayName;
 	}
 
@@ -296,7 +296,7 @@ export class NotebookModel extends Disposable implements INotebookModel {
 		return this._onValidConnectionSelected.event;
 	}
 
-	public get onActiveCellChanged(): Event<ICellModel> {
+	public get onActiveCellChanged(): Event<ICellModel | undefined> {
 		return this._onActiveCellChanged.event;
 	}
 
@@ -308,13 +308,13 @@ export class NotebookModel extends Disposable implements INotebookModel {
 		return this._standardKernels;
 	}
 
-	public set standardKernels(kernels) {
+	public set standardKernels(kernels: notebookUtils.IStandardKernelWithProvider[]) {
 		this._standardKernels = kernels;
 		this.setKernelDisplayNameMapsWithStandardKernels();
 	}
 
 	public getApplicableConnectionProviderIds(kernelDisplayName: string): string[] {
-		let ids = [];
+		let ids;
 		if (kernelDisplayName) {
 			ids = this._kernelDisplayNameToConnectionProviderIds.get(kernelDisplayName);
 		}
@@ -325,7 +325,7 @@ export class NotebookModel extends Disposable implements INotebookModel {
 		try {
 			this._trustedMode = isTrusted;
 
-			let contents = null;
+			let contents: nb.INotebookContents | undefined;
 
 			if (this._notebookOptions && this._notebookOptions.contentManager) {
 				contents = await this._notebookOptions.contentManager.loadContent();
@@ -334,16 +334,17 @@ export class NotebookModel extends Disposable implements INotebookModel {
 			// if cells already exist, create them with language info (if it is saved)
 			this._cells = [];
 			if (contents) {
-				this._defaultLanguageInfo = contents.metadata && contents.metadata.language_info;
+				this._defaultLanguageInfo = contents.metadata?.language_info;
 				this._savedKernelInfo = this.getSavedKernelInfo(contents);
 				if (contents.metadata) {
 					//Telemetry of loading notebook
-					if (contents.metadata.azdata_notebook_guid && contents.metadata.azdata_notebook_guid.length === 36) {
+					let metadata: any = contents.metadata;
+					if (metadata.azdata_notebook_guid && metadata.azdata_notebook_guid.length === 36) {
 						//Verify if it is actual GUID and then send it to the telemetry
 						let regex = new RegExp('(\{){0,1}[0-9a-fA-F]{8}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{4}\-[0-9a-fA-F]{12}(\}){0,1}');
-						if (regex.test(contents.metadata.azdata_notebook_guid)) {
+						if (regex.test(metadata.azdata_notebook_guid)) {
 							this.adstelemetryService.createActionEvent(TelemetryKeys.TelemetryView.Notebook, TelemetryKeys.TelemetryAction.Open)
-								.withAdditionalProperties({ azdata_notebook_guid: contents.metadata.azdata_notebook_guid })
+								.withAdditionalProperties({ azdata_notebook_guid: metadata.azdata_notebook_guid })
 								.send();
 						}
 					}
@@ -399,9 +400,9 @@ export class NotebookModel extends Disposable implements INotebookModel {
 		return this._cells.findIndex(cell => cell.equals(cellModel));
 	}
 
-	public addCell(cellType: CellType, index?: number): ICellModel {
+	public addCell(cellType: CellType, index?: number): ICellModel | undefined {
 		if (this.inErrorState) {
-			return null;
+			return undefined;
 		}
 		let cell = this.createCell(cellType);
 
@@ -425,7 +426,7 @@ export class NotebookModel extends Disposable implements INotebookModel {
 
 	moveCell(cell: ICellModel, direction: MoveDirection): void {
 		if (this.inErrorState) {
-			return null;
+			return;
 		}
 		let index = this.findCellIndex(cell);
 
@@ -457,12 +458,12 @@ export class NotebookModel extends Disposable implements INotebookModel {
 		});
 	}
 
-	public updateActiveCell(cell: ICellModel): void {
+	public updateActiveCell(cell?: ICellModel): void {
 		if (this._activeCell) {
 			this._activeCell.active = false;
 		}
 		this._activeCell = cell;
-		if (cell) {
+		if (this._activeCell) {
 			this._activeCell.active = true;
 		}
 		this._onActiveCellChanged.fire(cell);
@@ -501,7 +502,7 @@ export class NotebookModel extends Disposable implements INotebookModel {
 		if (index > -1) {
 			this._cells.splice(index, 1);
 			if (this._activeCell === cellModel) {
-				this.updateActiveCell(undefined);
+				this.updateActiveCell();
 			}
 			this._contentChangedEmitter.fire({
 				changeType: NotebookChangeType.CellsModified,
@@ -537,7 +538,7 @@ export class NotebookModel extends Disposable implements INotebookModel {
 		}
 	}
 
-	public get activeCell(): ICellModel {
+	public get activeCell(): ICellModel | undefined {
 		return this._activeCell;
 	}
 
@@ -546,7 +547,7 @@ export class NotebookModel extends Disposable implements INotebookModel {
 	}
 
 	public async startSession(manager: INotebookManager, displayName?: string, setErrorStateOnFail?: boolean, kernelAlias?: string): Promise<void> {
-		if (displayName && this._standardKernels) {
+		if (displayName) {
 			let standardKernel = this._standardKernels.find(kernel => kernel.displayName === displayName);
 			if (standardKernel) {
 				this._defaultKernel = { name: standardKernel.name, display_name: standardKernel.displayName };
@@ -641,7 +642,7 @@ export class NotebookModel extends Disposable implements INotebookModel {
 			this._defaultKernel = notebookConstants.sqlKernelSpec;
 			this._providerId = SQL_NOTEBOOK_PROVIDER;
 		}
-		if (!this._defaultLanguageInfo || this._defaultLanguageInfo.name) {
+		if (!this._defaultLanguageInfo?.name) {
 			// update default language
 			this._defaultLanguageInfo = {
 				name: this._providerId === SQL_NOTEBOOK_PROVIDER ? 'sql' : 'python',
@@ -651,10 +652,9 @@ export class NotebookModel extends Disposable implements INotebookModel {
 	}
 
 	private isValidConnection(profile: IConnectionProfile | connection.Connection) {
-		if (this._standardKernels) {
 		let standardKernels = this._standardKernels.find(kernel => this._defaultKernel && kernel.displayName === this._defaultKernel.display_name);
 		let connectionProviderIds = standardKernels ? standardKernels.connectionProviderIds : undefined;
-			let providerFeatures = this._capabilitiesService.getCapabilities(profile.providerName);
+		let providerFeatures = this._capabilitiesService?.getCapabilities(profile.providerName);
 		if (connectionProviderIds?.length) {
 			this._currentKernelAlias = providerFeatures?.connection.notebookKernelAlias;
 			// Switching from Kusto to another kernel should set the currentKernelAlias to undefined
@@ -667,30 +667,28 @@ export class NotebookModel extends Disposable implements INotebookModel {
 		}
 		return this._currentKernelAlias || profile && connectionProviderIds && connectionProviderIds.find(provider => provider === profile.providerName) !== undefined;
 	}
-		return false;
-	}
 
-	public getStandardKernelFromName(name: string): notebookUtils.IStandardKernelWithProvider {
+	public getStandardKernelFromName(name: string): notebookUtils.IStandardKernelWithProvider | undefined {
-		if (name && this._standardKernels) {
+		if (name) {
 			let kernel = this._standardKernels.find(kernel => kernel.name.toLowerCase() === name.toLowerCase());
 			return kernel;
 		}
 		return undefined;
 	}
 
-	public getStandardKernelFromDisplayName(displayName: string): notebookUtils.IStandardKernelWithProvider {
+	public getStandardKernelFromDisplayName(displayName: string): notebookUtils.IStandardKernelWithProvider | undefined {
-		if (displayName && this._standardKernels) {
+		if (displayName) {
 			let kernel = this._standardKernels.find(kernel => kernel.displayName.toLowerCase() === displayName.toLowerCase());
 			return kernel;
 		}
 		return undefined;
 	}
 
-	public get tags(): string[] {
+	public get tags(): string[] | undefined {
 		return this._tags;
 	}
 
-	public get languageInfo(): nb.ILanguageInfo {
+	public get languageInfo(): nb.ILanguageInfo | undefined {
 		return this._defaultLanguageInfo;
 	}
 
@@ -710,7 +708,7 @@ export class NotebookModel extends Disposable implements INotebookModel {
 		// If the "name" property isn't defined, check the "mimeType" property
 		// Otherwise, default to python as the language
 		let languageInfo = this.languageInfo;
-		let language: string;
+		let language: string = '';
 		if (languageInfo) {
 			if (languageInfo.codemirror_mode) {
 				let codeMirrorMode: nb.ICodeMirrorMode = <nb.ICodeMirrorMode>(languageInfo.codemirror_mode);
@@ -736,6 +734,8 @@ export class NotebookModel extends Disposable implements INotebookModel {
 			} else if (language.toLowerCase() === 'c#') {
 				language = 'cs';
 			}
+		} else {
+			language = 'python';
 		}
 
 		this._language = language.toLowerCase();
@@ -743,8 +743,8 @@ export class NotebookModel extends Disposable implements INotebookModel {
 
 	public changeKernel(displayName: string): void {
 		this._selectedKernelDisplayName = displayName;
-		this._currentKernelAlias = this.context?.serverCapabilities.notebookKernelAlias;
+		this._currentKernelAlias = this.context?.serverCapabilities?.notebookKernelAlias;
-		if (this.kernelAliases.includes(this.currentKernelAlias) && displayName === this.currentKernelAlias) {
+		if (this._currentKernelAlias && this.kernelAliases.includes(this._currentKernelAlias) && displayName === this._currentKernelAlias) {
 			this.doChangeKernel(displayName, true).catch(e => this.logService.error(e));
 		} else {
 			this._currentKernelAlias = undefined;
@@ -759,7 +759,7 @@ export class NotebookModel extends Disposable implements INotebookModel {
 			return;
 		}
 		let oldDisplayName = this._activeClientSession && this._activeClientSession.kernel ? this._activeClientSession.kernel.name : undefined;
-		let nbKernelAlias: string;
+		let nbKernelAlias: string | undefined;
 		if (this.kernelAliases.includes(displayName)) {
 			this._currentKernelAlias = displayName;
 			displayName = 'SQL';
@@ -778,7 +778,7 @@ export class NotebookModel extends Disposable implements INotebookModel {
 				if (this._activeClientSession && this._activeClientSession.isReady) {
 					let kernel = await this._activeClientSession.changeKernel(spec, this._oldKernel);
 					try {
-						await kernel.ready;
+						await kernel?.ready;
 						await this.updateKernelInfoOnKernelChange(kernel, nbKernelAlias);
 					} catch (err2) {
 						// TODO should we handle this in any way?
@@ -827,7 +827,7 @@ export class NotebookModel extends Disposable implements INotebookModel {
 			// Ensure that the kernel we try to switch to is a valid kernel; if not, use the default
 			let kernelSpecs = this.getKernelSpecs();
 			if (kernelSpecs && kernelSpecs.length > 0 && kernelSpecs.findIndex(k => k.display_name === spec.display_name) < 0) {
-				spec = kernelSpecs.find(spec => spec.name === this.notebookManager.sessionManager.specs.defaultKernel);
+				spec = kernelSpecs.find(spec => spec.name === this.notebookManager?.sessionManager.specs.defaultKernel);
 			}
 		}
 		else {
@@ -874,6 +874,7 @@ export class NotebookModel extends Disposable implements INotebookModel {
 
 	private setActiveConnectionIfDifferent(newConnection: ConnectionProfile) {
 		if (this.isValidConnection(newConnection) &&
+			this._activeConnection &&
 			this._activeConnection.id !== '-1' &&
 			this._activeConnection.id !== newConnection.id) {
 			// Change the active connection to newConnection
@@ -883,11 +884,11 @@ export class NotebookModel extends Disposable implements INotebookModel {
 
 
 	// Get default kernel info if saved in notebook file
-	private getSavedKernelInfo(notebook: nb.INotebookContents): nb.IKernelInfo {
+	private getSavedKernelInfo(notebook: nb.INotebookContents): nb.IKernelSpec | undefined {
 		return (notebook && notebook.metadata && notebook.metadata.kernelspec) ? notebook.metadata.kernelspec : undefined;
 	}
 
-	private getKernelSpecFromDisplayName(displayName: string): nb.IKernelSpec {
+	private getKernelSpecFromDisplayName(displayName: string): nb.IKernelSpec | undefined {
 		let kernel: nb.IKernelSpec = this.specs.kernels.find(k => k.display_name.toLowerCase() === displayName.toLowerCase());
 		if (!kernel) {
 			return undefined; // undefined is handled gracefully in the session to default to the default kernel
@@ -897,14 +898,13 @@ export class NotebookModel extends Disposable implements INotebookModel {
 		return kernel;
 	}
 
-	private sanitizeSavedKernelInfo() {
+	private sanitizeSavedKernelInfo(): void {
 		if (this._savedKernelInfo) {
 			let displayName = this._savedKernelInfo.display_name;
 
 			if (this._savedKernelInfo.display_name !== displayName) {
 				this._savedKernelInfo.display_name = displayName;
 			}
-			if (this._standardKernels) {
 			let standardKernel = this._standardKernels.find(kernel => kernel.displayName === displayName || startsWith(displayName, kernel.displayName));
 			if (standardKernel && this._savedKernelInfo.name && this._savedKernelInfo.name !== standardKernel.name) {
 				this._savedKernelInfo.name = standardKernel.name;
@@ -912,10 +912,9 @@ export class NotebookModel extends Disposable implements INotebookModel {
 			}
 		}
 	}
-	}
 
-	public getDisplayNameFromSpecName(kernel: nb.IKernel): string {
+	public getDisplayNameFromSpecName(kernel: nb.IKernel): string | undefined {
-		let specs = this.notebookManager.sessionManager.specs;
+		let specs = this.notebookManager?.sessionManager.specs;
 		if (!specs || !specs.kernels) {
 			return kernel.name;
 		}
@@ -972,7 +971,10 @@ export class NotebookModel extends Disposable implements INotebookModel {
 	private async loadActiveContexts(kernelChangedArgs: nb.IKernelChangedArgs): Promise<void> {
 		if (kernelChangedArgs && kernelChangedArgs.newValue && kernelChangedArgs.newValue.name) {
 			let kernelDisplayName = this.getDisplayNameFromSpecName(kernelChangedArgs.newValue);
-			let context = NotebookContexts.getContextForKernel(this._activeConnection, this.getApplicableConnectionProviderIds(kernelDisplayName));
+			let context;
+			if (this._activeConnection) {
+				context = NotebookContexts.getContextForKernel(this._activeConnection, this.getApplicableConnectionProviderIds(kernelDisplayName));
+			}
 			if (context !== undefined && context.serverName !== undefined && context.title !== undefined) {
 				await this.changeContext(context.title, context);
 			}
@@ -989,7 +991,7 @@ export class NotebookModel extends Disposable implements INotebookModel {
 					display_name: spec.display_name,
 					language: spec.language
 				};
-				this.clientSession.configureKernel(this._savedKernelInfo);
+				this.clientSession?.configureKernel(this._savedKernelInfo);
 			} catch (err) {
 				// Don't worry about this for now. Just use saved values
 			}
@@ -1024,7 +1026,7 @@ export class NotebookModel extends Disposable implements INotebookModel {
 		return false;
 	}
 
-	private tryFindProviderForKernel(displayName: string, alwaysReturnId: boolean = false): string {
+	private tryFindProviderForKernel(displayName: string, alwaysReturnId: boolean = false): string | undefined {
 		if (!displayName) {
 			return undefined;
 		}
@@ -1064,7 +1066,7 @@ export class NotebookModel extends Disposable implements INotebookModel {
 
 	// Disconnect any connections that were added through the "Change connection" functionality in the Attach To dropdown
 	private async disconnectAttachToConnections(): Promise<void> {
-		notebookUtils.asyncForEach(this._connectionUrisToDispose, async conn => {
+		notebookUtils.asyncForEach(this._connectionUrisToDispose, async (conn: string) => {
 			await this.notebookOptions.connectionService.disconnect(conn).catch(e => this.logService.error(e));
 		});
 		this._connectionUrisToDispose = [];
@@ -1095,7 +1097,6 @@ export class NotebookModel extends Disposable implements INotebookModel {
 	 * provider and notebook provider ids from a kernel display name
 	 */
 	private setKernelDisplayNameMapsWithStandardKernels(): void {
-		if (this._standardKernels) {
 		this._standardKernels.forEach(kernel => {
 			let displayName = kernel.displayName;
 			if (!displayName) {
@@ -1105,13 +1106,12 @@ export class NotebookModel extends Disposable implements INotebookModel {
 			this._kernelDisplayNameToNotebookProviderIds.set(displayName, kernel.notebookProvider);
 		});
 	}
-	}
 
 	/**
 	 * Serialize the model to JSON.
 	 */
 	toJSON(): nb.INotebookContents {
-		let cells: nb.ICellContents[] = this.cells.map(c => c.toJSON());
+		let cells: nb.ICellContents[] = this.cells?.map(c => c.toJSON());
 		let metadata = Object.create(null) as nb.INotebookMetadata;
 		// TODO update language and kernel when these change
 		metadata.kernelspec = this._savedKernelInfo;
@@ -1150,7 +1150,7 @@ export class NotebookModel extends Disposable implements INotebookModel {
 	serializationStateChanged(changeType: NotebookChangeType, cell?: ICellModel): void {
 		let changeInfo: NotebookContentChange = {
 			changeType: changeType,
-			cells: [cell]
+			cells: cell ? [cell] : []
 		};
 
 		this._contentChangedEmitter.fire(changeInfo);

src/sql/workbench/services/notebook/browser/sql/sqlNotebookManager.ts

@@ -28,7 +28,7 @@ export class SqlNotebookManager implements nb.NotebookProvider {
 		return this._contentManager;
 	}
 
-	public get serverManager(): nb.ServerManager {
+	public get serverManager(): nb.ServerManager | undefined {
 		return undefined;
 	}
 

src/sql/workbench/services/notebook/browser/sql/sqlSessionManager.ts

@@ -51,6 +51,26 @@ export interface SQLData {
 	rows: Array<Array<string>>;
 }
 
+export interface NotebookConfig {
+	cellToolbarLocation: string;
+	collapseBookItems: boolean;
+	diff: { enablePreview: boolean };
+	displayOrder: Array<string>;
+	kernelProviderAssociations: Array<string>;
+	maxBookSearchDepth: number;
+	maxTableRows: number;
+	overrideEditorTheming: boolean;
+	pinnedNotebooks: Array<string>;
+	pythonPath: string;
+	remoteBookDownloadTimeout: number;
+	showAllKernels: boolean;
+	showCellStatusBar: boolean;
+	showNotebookConvertActions: boolean;
+	sqlStopOnError: boolean;
+	trustedBooks: Array<string>;
+	useExistingPython: boolean;
+}
+
 export class SqlSessionManager implements nb.SessionManager {
 	private static _sessions: nb.ISession[] = [];
 
@@ -162,8 +182,8 @@ class SqlKernel extends Disposable implements nb.IKernel {
 	private _currentConnectionProfile: ConnectionProfile;
 	static kernelId: number = 0;
 
-	private _id: string;
+	private _id: string | undefined;
-	private _future: SQLFuture;
+	private _future: SQLFuture | undefined;
 	private _executionCount: number = 0;
 	private _magicToExecutorMap = new Map<string, ExternalScriptMagic>();
 	private _connectionPath: string;
@@ -301,7 +321,7 @@ class SqlKernel extends Disposable implements nb.IKernel {
 		}
 
 		// TODO should we  cleanup old future? I don't think we need to
-		return this._future;
+		return <nb.IFuture>this._future;
 	}
 
 	private getCodeWithoutCellMagic(content: nb.IExecuteRequest): string {
@@ -377,9 +397,9 @@ class SqlKernel extends Disposable implements nb.IKernel {
 }
 
 export class SQLFuture extends Disposable implements FutureInternal {
-	private _msg: nb.IMessage = undefined;
+	private _msg: nb.IMessage | undefined;
-	private ioHandler: nb.MessageHandler<nb.IIOPubMessage>;
+	private ioHandler: nb.MessageHandler<nb.IIOPubMessage> | undefined;
-	private doneHandler: nb.MessageHandler<nb.IShellMessage>;
+	private doneHandler: nb.MessageHandler<nb.IShellMessage> | undefined;
 	private doneDeferred = new Deferred<nb.IShellMessage>();
 	private configuredMaxRows: number = MAX_ROWS;
 	private _outputAddedPromises: Promise<void>[] = [];
@@ -387,13 +407,13 @@ export class SQLFuture extends Disposable implements FutureInternal {
 	private _errorOccurred: boolean = false;
 	private _stopOnError: boolean = true;
 	constructor(
-		private _queryRunner: QueryRunner,
+		private _queryRunner: QueryRunner | undefined,
 		private _executionCount: number | undefined,
 		configurationService: IConfigurationService,
 		private readonly logService: ILogService
 	) {
 		super();
-		let config = configurationService.getValue(NotebookConfigSectionName);
+		let config: NotebookConfig = configurationService.getValue(NotebookConfigSectionName);
 		if (config) {
 			let maxRows = config[MaxTableRowsConfigName] ? config[MaxTableRowsConfigName] : undefined;
 			if (maxRows && maxRows > 0) {
@@ -404,14 +424,16 @@ export class SQLFuture extends Disposable implements FutureInternal {
 	}
 
 	get inProgress(): boolean {
-		return this._queryRunner && !this._queryRunner.hasCompleted;
+		return this._queryRunner ? !this._queryRunner.hasCompleted : false;
 	}
+
 	set inProgress(val: boolean) {
 		if (this._queryRunner && !val) {
 			this._queryRunner.cancelQuery().catch(err => onUnexpectedError(err));
 		}
 	}
-	get msg(): nb.IMessage {
+
+	get msg(): nb.IMessage | undefined {
 		return this._msg;
 	}
 
@@ -468,9 +490,11 @@ export class SQLFuture extends Disposable implements FutureInternal {
 					message = this.convertToDisplayMessage(msg);
 				}
 			}
+			if (message) {
 				this.ioHandler.handle(message);
 			}
 		}
+	}
 
 	public handleBatchEnd(batch: BatchSummary): void {
 		if (this.ioHandler) {
@@ -545,7 +569,7 @@ export class SQLFuture extends Disposable implements FutureInternal {
 			metadata: undefined,
 			parent_header: undefined
 		};
-		this.ioHandler.handle(msg);
+		this.ioHandler?.handle(msg);
 		this._querySubsetResultMap.delete(resultSet.id);
 	}
 
@@ -605,7 +629,7 @@ export class SQLFuture extends Disposable implements FutureInternal {
 		return htmlStringArr;
 	}
 
-	private convertToDisplayMessage(msg: IResultMessage | string): nb.IIOPubMessage {
+	private convertToDisplayMessage(msg: IResultMessage | string): nb.IIOPubMessage | undefined {
 		if (msg) {
 			let msgData = typeof msg === 'string' ? msg : msg.message;
 			return {
@@ -627,7 +651,7 @@ export class SQLFuture extends Disposable implements FutureInternal {
 		return undefined;
 	}
 
-	private convertToError(msg: IResultMessage | string): nb.IIOPubMessage {
+	private convertToError(msg: IResultMessage | string): nb.IIOPubMessage | undefined {
 		this._errorOccurred = true;
 
 		if (msg) {