output channel: new replaceAll API to improve output channel rendering

src/vs/vscode.proposed.d.ts

@@ -2833,4 +2833,19 @@ declare module 'vscode' {
 	}
 
 	//#endregion
+
+	//#region https://github.com/microsoft/vscode/issues/132183
+	export interface OutputChannel {
+
+		/*
+		 * Replaces the existing contents of the channel with the given value.
+		 *
+		 * *Note*: this method should only be used by extensions with smaller output
+		 * channel text sizes. Use of `append` methods is preferred.
+		 */
+		replaceAll(value: string): void;
+
+	}
+
+	//#endregion
 }

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

@@ -81,6 +81,14 @@ export class MainThreadOutputService extends Disposable implements MainThreadOut
 		return undefined;
 	}
 
+	public $replaceAll(channelId: string, till: number, value: string): Promise<void> | undefined {
+		const channel = this._getChannel(channelId);
+		if (channel) {
+			channel.replaceAll(till, value);
+		}
+		return undefined;
+	}
+
 	public $reveal(channelId: string, preserveFocus: boolean): Promise<void> | undefined {
 		const channel = this._getChannel(channelId);
 		if (channel) {

src/vs/workbench/api/common/extHost.protocol.ts

@@ -447,6 +447,7 @@ export interface MainThreadOutputServiceShape extends IDisposable {
 	$append(channelId: string, value: string): Promise<void> | undefined;
 	$update(channelId: string): Promise<void> | undefined;
 	$clear(channelId: string, till: number): Promise<void> | undefined;
+	$replaceAll(channelId: string, till: number, value: string): Promise<void> | undefined;
 	$reveal(channelId: string, preserveFocus: boolean): Promise<void> | undefined;
 	$close(channelId: string): Promise<void> | undefined;
 	$dispose(channelId: string): Promise<void> | undefined;

src/vs/workbench/api/common/extHostOutput.ts

@@ -12,6 +12,7 @@ import { VSBuffer } from 'vs/base/common/buffer';
 import { createDecorator } from 'vs/platform/instantiation/common/instantiation';
 import { IExtHostRpcService } from 'vs/workbench/api/common/extHostRpcService';
 import { IExtensionDescription } from 'vs/platform/extensions/common/extensions';
+import { checkProposedApiEnabled } from 'vs/workbench/services/extensions/common/extensions';
 
 export abstract class AbstractExtHostOutputChannel extends Disposable implements vscode.OutputChannel {
 
@@ -20,18 +21,20 @@ export abstract class AbstractExtHostOutputChannel extends Disposable implements
 	protected readonly _proxy: MainThreadOutputServiceShape;
 	private _disposed: boolean;
 	private _offset: number;
+	private _extension: IExtensionDescription | undefined;
 
 	protected readonly _onDidAppend: Emitter<void> = this._register(new Emitter<void>());
 	readonly onDidAppend: Event<void> = this._onDidAppend.event;
 
-	constructor(name: string, log: boolean, file: URI | undefined, extensionId: string | undefined, proxy: MainThreadOutputServiceShape) {
+	constructor(name: string, log: boolean, file: URI | undefined, extension: IExtensionDescription | undefined, proxy: MainThreadOutputServiceShape) {
 		super();
 
 		this._name = name;
 		this._proxy = proxy;
-		this._id = proxy.$register(this.name, log, file, extensionId);
+		this._id = proxy.$register(this.name, log, file, extension?.identifier.value);
 		this._disposed = false;
 		this._offset = 0;
+		this._extension = extension;
 	}
 
 	get name(): string {
@@ -58,6 +61,17 @@ export abstract class AbstractExtHostOutputChannel extends Disposable implements
 		this._id.then(id => this._proxy.$clear(id, till));
 	}
 
+	replaceAll(value: string): void {
+		if (this._extension) {
+			checkProposedApiEnabled(this._extension);
+		}
+
+		this.validate();
+		const till = this._offset;
+		this._offset += value ? VSBuffer.fromString(value).byteLength : 0;
+		this._id.then(id => this._proxy.$replaceAll(id, till, value));
+	}
+
 	show(columnOrPreserveFocus?: vscode.ViewColumn | boolean, preserveFocus?: boolean): void {
 		this.validate();
 		this._id.then(id => this._proxy.$reveal(id, !!(typeof columnOrPreserveFocus === 'boolean' ? columnOrPreserveFocus : preserveFocus)));
@@ -87,8 +101,8 @@ export abstract class AbstractExtHostOutputChannel extends Disposable implements
 
 export class ExtHostPushOutputChannel extends AbstractExtHostOutputChannel {
 
-	constructor(name: string, extensionId: string, proxy: MainThreadOutputServiceShape) {
-		super(name, false, undefined, extensionId, proxy);
+	constructor(name: string, extension: IExtensionDescription, proxy: MainThreadOutputServiceShape) {
+		super(name, false, undefined, extension, proxy);
 	}
 
 	override append(value: string): void {
@@ -125,6 +139,9 @@ export class LazyOutputChannel implements vscode.OutputChannel {
 	clear(): void {
 		this._channel.then(channel => channel.clear());
 	}
+	replaceAll(value: string): void {
+		this._channel.then(channel => channel.replaceAll(value));
+	}
 	show(columnOrPreserveFocus?: vscode.ViewColumn | boolean, preserveFocus?: boolean): void {
 		this._channel.then(channel => channel.show(columnOrPreserveFocus, preserveFocus));
 	}
@@ -154,7 +171,7 @@ export class ExtHostOutputService implements ExtHostOutputServiceShape {
 		if (!name) {
 			throw new Error('illegal argument `name`. must not be falsy');
 		}
-		return new ExtHostPushOutputChannel(name, extension.identifier.value, this._proxy);
+		return new ExtHostPushOutputChannel(name, extension, this._proxy);
 	}
 
 	createOutputChannelFromLogFile(name: string, file: URI): vscode.OutputChannel {

src/vs/workbench/api/node/extHostOutputService.ts

@@ -44,8 +44,8 @@ class ExtHostOutputChannelBackedByFile extends AbstractExtHostOutputChannel {
 
 	private _appender: OutputAppender;
 
-	constructor(name: string, appender: OutputAppender, extensionId: string, proxy: MainThreadOutputServiceShape) {
-		super(name, false, URI.file(appender.file), extensionId, proxy);
+	constructor(name: string, appender: OutputAppender, extension: IExtensionDescription, proxy: MainThreadOutputServiceShape) {
+		super(name, false, URI.file(appender.file), extension, proxy);
 		this._appender = appender;
 	}
 
@@ -55,6 +55,12 @@ class ExtHostOutputChannelBackedByFile extends AbstractExtHostOutputChannel {
 		this._onDidAppend.fire();
 	}
 
+	override replaceAll(value: string): void {
+		this._appender.append(value);
+		this._appender.flush();
+		super.replaceAll(value);
+	}
+
 	override update(): void {
 		this._appender.flush();
 		super.update();
@@ -116,11 +122,11 @@ export class ExtHostOutputService2 extends ExtHostOutputService {
 			const fileName = `${this._namePool++}-${name.replace(/[\\/:\*\?"<>\|]/g, '')}`;
 			const file = URI.file(join(outputDirPath, `${fileName}.log`));
 			const appender = await OutputAppender.create(fileName, file.fsPath);
-			return new ExtHostOutputChannelBackedByFile(name, appender, extension.identifier.value, this._proxy);
+			return new ExtHostOutputChannelBackedByFile(name, appender, extension, this._proxy);
 		} catch (error) {
 			// Do not crash if logger cannot be created
 			this.logService.error(error);
-			return new ExtHostPushOutputChannel(name, extension.identifier.value, this._proxy);
+			return new ExtHostPushOutputChannel(name, extension, this._proxy);
 		}
 	}
 }

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

@@ -52,6 +52,10 @@ class OutputChannel extends Disposable implements IOutputChannel {
 	clear(till?: number): void {
 		this.model.clear(till);
 	}
+
+	replaceAll(till: number, value: string): void {
+		this.model.replaceAll(till, value);
+	}
 }
 
 export class OutputService extends Disposable implements IOutputService, ITextModelContentProvider {

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

@@ -127,6 +127,11 @@ export interface IOutputChannel {
 	 */
 	clear(till?: number): void;
 
+	/**
+	 * Replaces the output of the channel.
+	 */
+	replaceAll(till: number, value: string): void;
+
 	/**
 	 * Disposes the output channel.
 	 */