Strict null work

src/vs/base/parts/quickopen/browser/quickOpenViewer.ts

@@ -33,7 +33,7 @@ export class DataSource implements IDataSource {
 
 	hasChildren(tree: ITree, element: any): boolean {
 		const model = this.modelProvider.getModel();
-		return model && model === element && model.entries.length > 0;
+		return !!(model && model === element && model.entries.length > 0);
 	}
 
 	getChildren(tree: ITree, element: any): Promise<any[]> {

src/vs/base/parts/tree/browser/treeView.ts

@@ -1286,8 +1286,8 @@ export class TreeView extends HeightMap {
 				element = this.model!.getInput();
 				position = DOM.getDomNodePagePosition(this.inputItem.element);
 			} else {
-				let id = this.context.dataSource.getId(this.context.tree, element);
-				let viewItem = this.items[id];
+				const id = this.context.dataSource.getId(this.context.tree, element);
+				const viewItem = this.items[id!];
 				position = DOM.getDomNodePagePosition(viewItem.element);
 			}
 

src/vs/workbench/contrib/extensions/electron-browser/extensionsList.ts

@@ -34,7 +34,7 @@ export interface ITemplateData {
 	ratings: HTMLElement;
 	author: HTMLElement;
 	description: HTMLElement;
-	extension: IExtension;
+	extension: IExtension | null;
 	disposables: IDisposable[];
 	extensionDisposables: IDisposable[];
 	actionbar: ActionBar;

src/vs/workbench/contrib/extensions/electron-browser/extensionsWidgets.ts

@@ -142,7 +142,7 @@ export class RatingsWidget extends ExtensionWidget {
 
 export class RecommendationWidget extends ExtensionWidget {
 
-	private element: HTMLElement;
+	private element?: HTMLElement;
 	private disposables: IDisposable[] = [];
 
 	constructor(
@@ -161,7 +161,7 @@ export class RecommendationWidget extends ExtensionWidget {
 		if (this.element) {
 			this.parent.removeChild(this.element);
 		}
-		this.element = null;
+		this.element = undefined;
 		this.disposables = dispose(this.disposables);
 	}
 
@@ -232,6 +232,9 @@ export class RemoteBadgeWidget extends ExtensionWidget {
 			append(this.element, $('span.octicon.octicon-file-symlink-directory'));
 
 			const applyBadgeStyle = () => {
+				if (!this.element) {
+					return;
+				}
 				const bgColor = this.themeService.getTheme().getColor(STATUS_BAR_HOST_NAME_BACKGROUND);
 				const fgColor = this.workspaceContextService.getWorkbenchState() === WorkbenchState.EMPTY ? this.themeService.getTheme().getColor(STATUS_BAR_NO_FOLDER_FOREGROUND) : this.themeService.getTheme().getColor(STATUS_BAR_FOREGROUND);
 				this.element.style.backgroundColor = bgColor ? bgColor.toString() : '';
@@ -241,7 +244,11 @@ export class RemoteBadgeWidget extends ExtensionWidget {
 			this.themeService.onThemeChange(applyBadgeStyle, this, this.disposables);
 			this.workspaceContextService.onDidChangeWorkbenchState(applyBadgeStyle, this, this.disposables);
 
-			const updateTitle = () => this.element.title = localize('remote extension title', "Extension in {0}", this.labelService.getHostLabel());
+			const updateTitle = () => {
+				if (this.element) {
+					this.element.title = localize('remote extension title', "Extension in {0}", this.labelService.getHostLabel());
+				}
+			};
 			this.labelService.onDidChangeFormatters(() => updateTitle(), this, this.disposables);
 			updateTitle();
 		}