IActionItemProvider should return undefined instead of null

#70020

src/vs/base/browser/contextmenu.ts

@@ -25,7 +25,7 @@ export class ContextSubMenu extends SubmenuAction {
 export interface IContextMenuDelegate {
 	getAnchor(): HTMLElement | { x: number; y: number; width?: number; height?: number; };
 	getActions(): Array<IAction | ContextSubMenu>;
-	getActionItem?(action: IAction): IActionItem | null;
+	getActionItem?(action: IAction): IActionItem | undefined;
 	getActionsContext?(event?: IContextMenuEvent): any;
 	getKeyBinding?(action: IAction): ResolvedKeybinding | undefined;
 	getMenuClassName?(): string;

src/vs/base/browser/ui/actionbar/actionbar.ts

@@ -364,7 +364,7 @@ export interface ActionTrigger {
 }
 
 export interface IActionItemProvider {
-	(action: IAction): IActionItem | null;
+	(action: IAction): IActionItem | undefined;
 }
 
 export interface IActionBarOptions {
@@ -609,7 +609,7 @@ export class ActionBar extends Disposable implements IActionRunner {
 				e.stopPropagation();
 			}));
 
-			let item: IActionItem | null = null;
+			let item: IActionItem | undefined;
 
 			if (this.options.actionItemProvider) {
 				item = this.options.actionItemProvider(action);

src/vs/base/browser/ui/dropdown/dropdown.ts

@@ -247,7 +247,7 @@ export class DropdownMenu extends BaseDropdown {
 			getAnchor: () => this.element,
 			getActions: () => this.actions,
 			getActionsContext: () => this.menuOptions ? this.menuOptions.context : null,
-			getActionItem: action => this.menuOptions && this.menuOptions.actionItemProvider ? this.menuOptions.actionItemProvider(action) : null,
+			getActionItem: action => this.menuOptions && this.menuOptions.actionItemProvider ? this.menuOptions.actionItemProvider(action) : undefined,
 			getKeyBinding: action => this.menuOptions && this.menuOptions.getKeyBinding ? this.menuOptions.getKeyBinding(action) : undefined,
 			getMenuClassName: () => this.menuClassName,
 			onHide: () => this.onHide(),

src/vs/base/browser/ui/toolbar/toolbar.ts

@@ -75,10 +75,10 @@ export class ToolBar extends Disposable {
 					);
 					this.toggleMenuActionItem!.setActionContext(this.actionBar.context);
 
-					return this.toggleMenuActionItem || null;
+					return this.toggleMenuActionItem;
 				}
 
-				return options.actionItemProvider ? options.actionItemProvider(action) : null;
+				return options.actionItemProvider ? options.actionItemProvider(action) : undefined;
 			}
 		}));
 	}

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

@@ -300,8 +300,8 @@ class NoActionProvider implements IActionProvider {
 		return null;
 	}
 
-	getActionItem(tree: ITree, element: any, action: Action): IActionItem | null {
-		return null;
+	getActionItem(tree: ITree, element: any, action: Action): IActionItem | undefined {
+		return undefined;
 	}
 }
 

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

@@ -736,5 +736,5 @@ export interface IActionProvider {
 	/**
 	 * Returns an action item to render an action.
 	 */
-	getActionItem(tree: ITree, element: any, action: IAction): IActionItem | null;
+	getActionItem(tree: ITree, element: any, action: IAction): IActionItem | undefined;
 }

src/vs/workbench/browser/actions.ts

@@ -130,7 +130,7 @@ export class ContributableActionProvider implements IActionProvider {
 		return prepareActions(actions);
 	}
 
-	getActionItem(tree: ITree, element: any, action: Action): BaseActionItem | null {
+	getActionItem(tree: ITree, element: any, action: Action): BaseActionItem | undefined {
 		const contributors = this.registry.getActionBarContributors(Scope.VIEWER);
 		const context = this.toContext(tree, element);
 
@@ -143,7 +143,7 @@ export class ContributableActionProvider implements IActionProvider {
 			}
 		}
 
-		return null;
+		return undefined;
 	}
 }
 

src/vs/workbench/browser/composite.ts

@@ -166,11 +166,11 @@ export abstract class Composite extends Component implements IComposite {
 	/**
 	 * For any of the actions returned by this composite, provide an IActionItem in
 	 * cases where the implementor of the composite wants to override the presentation
-	 * of an action. Returns null to indicate that the action is not rendered through
+	 * of an action. Returns undefined to indicate that the action is not rendered through
 	 * an action item.
 	 */
-	getActionItem(action: IAction): IActionItem | null {
-		return null;
+	getActionItem(action: IAction): IActionItem | undefined {
+		return undefined;
 	}
 
 	/**

src/vs/workbench/browser/parts/compositeBar.ts

@@ -50,7 +50,7 @@ export class CompositeBar extends Widget implements ICompositeBar {
 
 	private compositeSwitcherBar: ActionBar;
 	private compositeOverflowAction: CompositeOverflowActivityAction | null;
-	private compositeOverflowActionItem: CompositeOverflowActivityActionItem | null;
+	private compositeOverflowActionItem: CompositeOverflowActivityActionItem | undefined;
 
 	private model: CompositeBarModel;
 	private visibleComposites: string[];
@@ -345,7 +345,7 @@ export class CompositeBar extends Widget implements ICompositeBar {
 			if (this.compositeOverflowActionItem) {
 				this.compositeOverflowActionItem.dispose();
 			}
-			this.compositeOverflowActionItem = null;
+			this.compositeOverflowActionItem = undefined;
 		}
 
 		// Pull out composites that overflow or got hidden

src/vs/workbench/browser/parts/compositePart.ts

@@ -432,14 +432,14 @@ export abstract class CompositePart<T extends Composite> extends Part {
 		this.titleLabel.updateStyles();
 	}
 
-	protected actionItemProvider(action: Action): IActionItem | null {
+	protected actionItemProvider(action: Action): IActionItem | undefined {
 
 		// Check Active Composite
 		if (this.activeComposite) {
 			return this.activeComposite.getActionItem(action);
 		}
 
-		return null;
+		return undefined;
 	}
 
 	protected actionsContextProvider(): any {

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

@@ -39,7 +39,6 @@ import { Themable } from 'vs/workbench/common/theme';
 import { IExtensionService } from 'vs/workbench/services/extensions/common/extensions';
 import { AnchorAlignment } from 'vs/base/browser/ui/contextview/contextview';
 import { IFileService } from 'vs/platform/files/common/files';
-import { withUndefinedAsNull } from 'vs/base/common/types';
 
 export interface IToolbarActions {
 	primary: IAction[];
@@ -155,18 +154,18 @@ export abstract class TitleControl extends Themable {
 		}));
 	}
 
-	private actionItemProvider(action: Action): IActionItem | null {
+	private actionItemProvider(action: Action): IActionItem | undefined {
 		const activeControl = this.group.activeControl;
 
 		// Check Active Editor
-		let actionItem: IActionItem | null = null;
+		let actionItem: IActionItem | undefined = undefined;
 		if (activeControl instanceof BaseEditor) {
 			actionItem = activeControl.getActionItem(action);
 		}
 
 		// Check extensions
 		if (!actionItem) {
-			actionItem = withUndefinedAsNull(createActionItem(action, this.keybindingService, this.notificationService, this.contextMenuService));
+			actionItem = createActionItem(action, this.keybindingService, this.notificationService, this.contextMenuService);
 		}
 
 		return actionItem;

src/vs/workbench/browser/parts/notifications/notificationsViewer.ts

@@ -227,7 +227,7 @@ export class NotificationRenderer implements IListRenderer<INotificationViewItem
 						return item;
 					}
 
-					return null;
+					return undefined;
 				},
 				actionRunner: this.actionRunner
 			}

src/vs/workbench/browser/parts/views/customView.ts

@@ -87,8 +87,8 @@ export class CustomTreeViewPanel extends ViewletPanel {
 		return [...this.treeView.getSecondaryActions()];
 	}
 
-	getActionItem(action: IAction): IActionItem | null {
-		return action instanceof MenuItemAction ? new ContextAwareMenuItemActionItem(action, this.keybindingService, this.notificationService, this.contextMenuService) : null;
+	getActionItem(action: IAction): IActionItem | undefined {
+		return action instanceof MenuItemAction ? new ContextAwareMenuItemActionItem(action, this.keybindingService, this.notificationService, this.contextMenuService) : undefined;
 	}
 
 	getOptimalWidth(): number {
@@ -378,7 +378,7 @@ export class CustomTreeView extends Disposable implements ITreeView {
 	}
 
 	private createTree() {
-		const actionItemProvider = (action: IAction) => action instanceof MenuItemAction ? this.instantiationService.createInstance(ContextAwareMenuItemActionItem, action) : null;
+		const actionItemProvider = (action: IAction) => action instanceof MenuItemAction ? this.instantiationService.createInstance(ContextAwareMenuItemActionItem, action) : undefined;
 		const menus = this._register(this.instantiationService.createInstance(TreeMenus, this.id));
 		this.treeLabels = this._register(this.instantiationService.createInstance(ResourceLabels, this));
 		const dataSource = this.instantiationService.createInstance(TreeDataSource, this, <T>(task: Promise<T>) => this.progressService.withProgress({ location: this.viewContainer.id }, () => task));
@@ -814,7 +814,7 @@ class TreeController extends WorkbenchTreeController {
 				if (keybinding) {
 					return new ActionItem(action, action, { label: true, keybinding: keybinding.getLabel() });
 				}
-				return null;
+				return undefined;
 			},
 
 			onHide: (wasCancelled?: boolean) => {

src/vs/workbench/browser/parts/views/panelViewlet.ts

@@ -174,8 +174,8 @@ export abstract class ViewletPanel extends Panel implements IView {
 		return [];
 	}
 
-	getActionItem(action: IAction): IActionItem | null {
-		return null;
+	getActionItem(action: IAction): IActionItem | undefined {
+		return undefined;
 	}
 
 	getActionsContext(): any {
@@ -282,7 +282,7 @@ export class PanelViewlet extends Viewlet {
 		return [];
 	}
 
-	getActionItem(action: IAction): IActionItem | null {
+	getActionItem(action: IAction): IActionItem | undefined {
 		if (this.isSingleView()) {
 			return this.panelItems[0].panel.getActionItem(action);
 		}

src/vs/workbench/common/composite.ts

@@ -35,7 +35,7 @@ export interface IComposite {
 	/**
 	 * Returns the action item for a specific action.
 	 */
-	getActionItem(action: IAction): IActionItem | null;
+	getActionItem(action: IAction): IActionItem | undefined;
 
 	/**
 	 * Returns the underlying control of this composite.

src/vs/workbench/contrib/debug/browser/debugToolbar.ts

@@ -95,7 +95,7 @@ export class DebugToolbar extends Themable implements IWorkbenchContribution {
 					return new MenuItemActionItem(action, this.keybindingService, this.notificationService, contextMenuService);
 				}
 
-				return null;
+				return undefined;
 			}
 		}));
 

src/vs/workbench/contrib/debug/browser/debugViewlet.ts

@@ -129,7 +129,7 @@ export class DebugViewlet extends ViewContainerViewlet {
 		return [this.selectAndStartAction, this.configureAction, this.toggleReplAction];
 	}
 
-	getActionItem(action: IAction): IActionItem | null {
+	getActionItem(action: IAction): IActionItem | undefined {
 		if (action.id === StartAction.ID) {
 			this.startDebugActionItem = this.instantiationService.createInstance(StartDebugActionItem, null, action);
 			return this.startDebugActionItem;
@@ -141,7 +141,7 @@ export class DebugViewlet extends ViewContainerViewlet {
 			return new MenuItemActionItem(action, this.keybindingService, this.notificationService, this.contextMenuService);
 		}
 
-		return null;
+		return undefined;
 	}
 
 	focusView(id: string): void {

src/vs/workbench/contrib/debug/browser/repl.ts

@@ -309,12 +309,12 @@ export class Repl extends Panel implements IPrivateReplService, IHistoryNavigati
 		this.replInput.focus();
 	}
 
-	getActionItem(action: IAction): IActionItem | null {
+	getActionItem(action: IAction): IActionItem | undefined {
 		if (action.id === SelectReplAction.ID) {
 			return this.instantiationService.createInstance(SelectReplActionItem, this.selectReplAction);
 		}
 
-		return null;
+		return undefined;
 	}
 
 	getActions(): IAction[] {

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

@@ -254,7 +254,7 @@ export class ExtensionEditor extends BaseEditor {
 				if (action instanceof ExtensionEditorDropDownAction) {
 					return action.createActionItem();
 				}
-				return null;
+				return undefined;
 			}
 		});
 

src/vs/workbench/contrib/markers/browser/markersPanel.ts

@@ -628,7 +628,7 @@ export class MarkersPanel extends Panel implements IMarkerFilterController {
 				if (keybinding) {
 					return new ActionItem(action, action, { label: true, keybinding: keybinding.getLabel() });
 				}
-				return null;
+				return undefined;
 			},
 			onHide: (wasCancelled?: boolean) => {
 				if (wasCancelled) {
@@ -670,7 +670,7 @@ export class MarkersPanel extends Panel implements IMarkerFilterController {
 		return this.tree.getFocus()[0];
 	}
 
-	public getActionItem(action: IAction): IActionItem | null {
+	public getActionItem(action: IAction): IActionItem | undefined {
 		if (action.id === MarkersFilterAction.ID) {
 			this.filterInputActionItem = this.instantiationService.createInstance(MarkersFilterActionItem, this.filterAction, this);
 			return this.filterInputActionItem;

src/vs/workbench/contrib/markers/browser/markersTreeViewer.ts

@@ -253,7 +253,7 @@ class MarkerWidget extends Disposable {
 	) {
 		super();
 		this.actionBar = this._register(new ActionBar(dom.append(parent, dom.$('.actions')), {
-			actionItemProvider: (action) => action.id === QuickFixAction.ID ? instantiationService.createInstance(QuickFixActionItem, action) : null
+			actionItemProvider: (action) => action.id === QuickFixAction.ID ? instantiationService.createInstance(QuickFixActionItem, action) : undefined
 		}));
 		this.icon = dom.append(parent, dom.$('.icon'));
 		this.multilineActionbar = this._register(new ActionBar(dom.append(parent, dom.$('.multiline-actions'))));

src/vs/workbench/contrib/output/browser/outputPanel.ts

@@ -75,7 +75,7 @@ export class OutputPanel extends AbstractTextResourceEditor {
 		return this.actions;
 	}
 
-	public getActionItem(action: Action): IActionItem | null {
+	public getActionItem(action: Action): IActionItem | undefined {
 		if (action.id === SwitchOutputAction.ID) {
 			return this.instantiationService.createInstance(SwitchOutputActionItem, action);
 		}

src/vs/workbench/contrib/preferences/browser/keybindingsEditor.ts

@@ -376,7 +376,7 @@ export class KeybindingsEditor extends BaseEditor implements IKeybindingsEditor
 				if (action.id === this.recordKeysAction.id) {
 					return new CheckboxActionItem(null, action);
 				}
-				return null;
+				return undefined;
 			}
 		}));
 

src/vs/workbench/contrib/preferences/browser/preferencesWidgets.ts

@@ -424,7 +424,7 @@ export class FolderSettingsActionItem extends BaseActionItem {
 		this.contextMenuService.showContextMenu({
 			getAnchor: () => this.container,
 			getActions: () => this.getDropdownMenuActions(),
-			getActionItem: () => null,
+			getActionItem: () => undefined,
 			onHide: () => {
 				this.anchorElement.blur();
 			}
@@ -495,7 +495,7 @@ export class SettingsTargetsWidget extends Widget {
 			orientation: ActionsOrientation.HORIZONTAL,
 			ariaLabel: localize('settingsSwitcherBarAriaLabel', "Settings Switcher"),
 			animated: false,
-			actionItemProvider: (action: Action) => action.id === 'folderSettings' ? this.folderSettings : null
+			actionItemProvider: (action: Action) => action.id === 'folderSettings' ? this.folderSettings : undefined
 		}));
 
 		this.userSettings = new Action('userSettings', localize('userSettings', "User Settings"), '.settings-tab', true, () => this.updateTarget(ConfigurationTarget.USER));

src/vs/workbench/contrib/scm/browser/dirtydiffDecorator.ts

@@ -294,9 +294,9 @@ class DirtyDiffWidget extends PeekViewWidget {
 		};
 	}
 
-	getActionItem(action: IAction): IActionItem | null {
+	getActionItem(action: IAction): IActionItem | undefined {
 		if (!(action instanceof MenuItemAction)) {
-			return null;
+			return undefined;
 		}
 
 		return new DiffMenuItemActionItem(action, this.keybindingService, this.notificationService, this.contextMenuService);

src/vs/workbench/contrib/scm/browser/scmViewlet.ts

@@ -918,9 +918,9 @@ export class RepositoryPanel extends ViewletPanel {
 		return this.menus.getTitleSecondaryActions();
 	}
 
-	getActionItem(action: IAction): IActionItem | null {
+	getActionItem(action: IAction): IActionItem | undefined {
 		if (!(action instanceof MenuItemAction)) {
-			return null;
+			return undefined;
 		}
 
 		return new ContextAwareMenuItemActionItem(action, this.keybindingService, this.notificationService, this.contextMenuService);
@@ -1221,9 +1221,9 @@ export class SCMViewlet extends ViewContainerViewlet implements IViewModel {
 		}
 	}
 
-	getActionItem(action: IAction): IActionItem | null {
+	getActionItem(action: IAction): IActionItem | undefined {
 		if (!(action instanceof MenuItemAction)) {
-			return null;
+			return undefined;
 		}
 
 		return new ContextAwareMenuItemActionItem(action, this.keybindingService, this.notificationService, this.contextMenuService);

src/vs/workbench/contrib/terminal/browser/terminalPanel.ts

@@ -161,7 +161,7 @@ export class TerminalPanel extends Panel {
 		return this._contextMenuActions;
 	}
 
-	public getActionItem(action: Action): IActionItem | null {
+	public getActionItem(action: Action): IActionItem | undefined {
 		if (action.id === SwitchTerminalAction.ID) {
 			return this._instantiationService.createInstance(SwitchTerminalActionItem, action);
 		}