Make getResource return undefined

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

@@ -140,8 +140,8 @@ export class QuickOpenEntry {
 	 * A resource for this entry. Resource URIs can be used to compare different kinds of entries and group
 	 * them together.
 	 */
-	getResource(): URI | null {
-		return null;
+	getResource(): URI | undefined {
+		return undefined;
 	}
 
 	/**
@@ -245,7 +245,7 @@ export class QuickOpenEntryGroup extends QuickOpenEntry {
 		return this.entry ? this.entry.getDetail() : super.getDetail();
 	}
 
-	getResource(): URI | null {
+	getResource(): URI | undefined {
 		return this.entry ? this.entry.getResource() : super.getResource();
 	}
 

src/vs/workbench/browser/parts/editor/editorPicker.ts

@@ -18,6 +18,7 @@ import { IInstantiationService } from 'vs/platform/instantiation/common/instanti
 import { EditorInput, toResource, SideBySideEditor } from 'vs/workbench/common/editor';
 import { compareItemsByScore, scoreItem, ScorerCache, prepareQuery } from 'vs/base/parts/quickopen/common/quickOpenScorer';
 import { CancellationToken } from 'vs/base/common/cancellation';
+import { withNullAsUndefined } from 'vs/base/common/types';
 
 export class EditorPickerEntry extends QuickOpenEntryGroup {
 
@@ -32,7 +33,7 @@ export class EditorPickerEntry extends QuickOpenEntryGroup {
 
 	getLabelOptions(): IIconLabelValueOptions {
 		return {
-			extraClasses: getIconClasses(this.modelService, this.modeService, this.getResource() || undefined),
+			extraClasses: getIconClasses(this.modelService, this.modeService, this.getResource()),
 			italic: !this._group.isPinned(this.editor)
 		};
 	}
@@ -50,7 +51,7 @@ export class EditorPickerEntry extends QuickOpenEntryGroup {
 	}
 
 	getResource() {
-		return toResource(this.editor, { supportSideBySide: SideBySideEditor.MASTER });
+		return withNullAsUndefined(toResource(this.editor, { supportSideBySide: SideBySideEditor.MASTER }));
 	}
 
 	getAriaLabel(): string {

src/vs/workbench/browser/parts/quickopen/quickOpenController.ts

@@ -782,8 +782,8 @@ export class EditorHistoryEntry extends EditorQuickOpenEntry {
 		return this.description;
 	}
 
-	getResource(): URI | null {
-		return types.withUndefinedAsNull(this.resource);
+	getResource(): URI | undefined {
+		return this.resource;
 	}
 
 	getInput(): IEditorInput | IResourceInput {
@@ -848,7 +848,7 @@ export class RemoveFromEditorHistoryAction extends Action {
 
 			return <IHistoryPickEntry>{
 				input: h,
-				iconClasses: getIconClasses(this.modelService, this.modeService, types.withNullAsUndefined(entry.getResource())),
+				iconClasses: getIconClasses(this.modelService, this.modeService, entry.getResource()),
 				label: entry.getLabel(),
 				description: entry.getDescription()
 			};