Convert undefined -> null in IOutputService

src/vs/workbench/api/browser/mainThreadOutputService.ts

@@ -38,7 +38,7 @@ export class MainThreadOutputService extends Disposable implements MainThreadOut
 
 		const setVisibleChannel = () => {
 			const panel = this._panelService.getActivePanel();
-			const visibleChannel: IOutputChannel | null = panel && panel.getId() === OUTPUT_PANEL_ID ? this._outputService.getActiveChannel() : null;
+			const visibleChannel = panel && panel.getId() === OUTPUT_PANEL_ID ? this._outputService.getActiveChannel() : undefined;
 			this._proxy.$setVisibleChannel(visibleChannel ? visibleChannel.id : null);
 		};
 		this._register(Event.any<any>(this._outputService.onActiveOutputChannel, this._panelService.onDidPanelOpen, this._panelService.onDidPanelClose)(() => setVisibleChannel()));
@@ -104,7 +104,7 @@ export class MainThreadOutputService extends Disposable implements MainThreadOut
 		return undefined;
 	}
 
-	private _getChannel(channelId: string): IOutputChannel | null {
+	private _getChannel(channelId: string): IOutputChannel | undefined {
 		return this._outputService.getChannel(channelId);
 	}
 }

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

@@ -27,7 +27,6 @@ import { ILifecycleService } from 'vs/platform/lifecycle/common/lifecycle';
 import { IContextKeyService } from 'vs/platform/contextkey/common/contextkey';
 import { CancellationToken } from 'vs/base/common/cancellation';
 import { IOutputChannelModel, IOutputChannelModelService } from 'vs/workbench/services/output/common/outputChannelModel';
-import { withUndefinedAsNull } from 'vs/base/common/types';
 
 const OUTPUT_ACTIVE_CHANNEL_KEY = 'output.activechannel';
 
@@ -67,7 +66,7 @@ export class OutputService extends Disposable implements IOutputService, ITextMo
 
 	private channels: Map<string, OutputChannel> = new Map<string, OutputChannel>();
 	private activeChannelIdInStorage: string;
-	private activeChannel: OutputChannel | null;
+	private activeChannel?: OutputChannel;
 
 	private readonly _onActiveOutputChannel = new Emitter<string>();
 	readonly onActiveOutputChannel: Event<string> = this._onActiveOutputChannel.event;
@@ -106,7 +105,7 @@ export class OutputService extends Disposable implements IOutputService, ITextMo
 		// Set active channel to first channel if not set
 		if (!this.activeChannel) {
 			const channels = this.getChannelDescriptors();
-			this.activeChannel = channels && channels.length > 0 ? this.getChannel(channels[0].id) : null;
+			this.activeChannel = channels && channels.length > 0 ? this.getChannel(channels[0].id) : undefined;
 		}
 
 		this._register(this.lifecycleService.onShutdown(() => this.dispose()));
@@ -141,15 +140,15 @@ export class OutputService extends Disposable implements IOutputService, ITextMo
 		return promise.then(() => this._onActiveOutputChannel.fire(id));
 	}
 
-	getChannel(id: string): OutputChannel | null {
-		return withUndefinedAsNull(this.channels.get(id));
+	getChannel(id: string): OutputChannel | undefined {
+		return this.channels.get(id);
 	}
 
 	getChannelDescriptors(): IOutputChannelDescriptor[] {
 		return Registry.as<IOutputChannelRegistry>(Extensions.OutputChannels).getChannels();
 	}
 
-	getActiveChannel(): IOutputChannel | null {
+	getActiveChannel(): IOutputChannel | undefined {
 		return this.activeChannel;
 	}
 
@@ -195,7 +194,7 @@ export class OutputService extends Disposable implements IOutputService, ITextMo
 		channel.model.onDispose(() => {
 			if (this.activeChannel === channel) {
 				const channels = this.getChannelDescriptors();
-				const channel = channels.length ? this.getChannel(channels[0].id) : null;
+				const channel = channels.length ? this.getChannel(channels[0].id) : undefined;
 				if (channel && this.isPanelShown()) {
 					this.showChannel(channel.id, true);
 				} else {

src/vs/workbench/contrib/output/common/output.ts

@@ -68,7 +68,7 @@ export interface IOutputService {
 	 * Given the channel id returns the output channel instance.
 	 * Channel should be first registered via OutputChannelRegistry.
 	 */
-	getChannel(id: string): IOutputChannel | null;
+	getChannel(id: string): IOutputChannel | undefined;
 
 	/**
 	 * Returns an array of all known output channels descriptors.
@@ -79,7 +79,7 @@ export interface IOutputService {
 	 * Returns the currently active channel.
 	 * Only one channel can be active at a given moment.
 	 */
-	getActiveChannel(): IOutputChannel | null;
+	getActiveChannel(): IOutputChannel | undefined;
 
 	/**
 	 * Show the channel with the passed id.