Fixes #22655.

extensions/gulp/src/main.ts

@@ -73,7 +73,8 @@ function getGulpTasks(): Thenable<vscode.TaskSet> {
 						if (line.length === 0) {
 							continue;
 						}
-						result.tasks.push(new vscode.ShellTask(`gulp ${line}`, `gulp ${line}`));
+						let task = new vscode.ShellTask(`gulp ${line}`, `gulp ${line}`);
+						result.tasks.push(task);
 						let lowerCaseLine = line.toLowerCase();
 						if (lowerCaseLine === 'build') {
 							buildTask = { id: line, rank: 2 };

src/vs/vscode.proposed.d.ts

@@ -256,6 +256,11 @@ declare module 'vscode' {
 		 * Defaults to `RevealKind.Always`.
 		 */
 		reveal?: RevealKind;
+
+		/**
+		 * Controls whether the command is echoed in the terminal or not.
+		 */
+		echo?: boolean;
 	}
 
 
@@ -331,24 +336,26 @@ declare module 'vscode' {
 		readonly process: string;
 
 		/**
-		 * The arguments passed to the process. Can be omitted.
+		 * The arguments passed to the process. Defaults to an empty array.
 		 */
-		args?: string[];
+		args: string[];
 
 		/**
-		 * The process options used when the process is executed. Can be omitted.
+		 * The process options used when the process is executed.
+		 * Defaults to an empty object literal.
 		 */
-		options?: ProcessOptions;
+		options: ProcessOptions;
 
 		/**
-		 * The terminal options. Can be omitted.
+		 * The terminal options. Defaults to an empty object literal.
 		 */
-		terminal?: TerminalBehaviour;
+		terminal: TerminalBehaviour;
 
 		/**
-		 * The problem matchers attached to the task.
+		 * The problem matchers attached to the task. Defaults to an empty
+		 * array.
 		 */
-		readonly problemMatchers?: ProblemMatcher[];
+		problemMatchers: ProblemMatcher[];
 	}
 
 	export interface ShellOptions {
@@ -422,19 +429,21 @@ declare module 'vscode' {
 		readonly commandLine: string;
 
 		/**
-		 * The shell options used when the shell is executed. Can be omitted.
+		 * The shell options used when the shell is executed. Defaults to an
+		 * empty object literal.
 		 */
-		options?: ShellOptions;
+		options: ShellOptions;
 
 		/**
-		 * The terminal options. Can be omitted.
+		 * The terminal options. Defaults to an empty object literal.
 		 */
-		terminal?: TerminalBehaviour;
+		terminal: TerminalBehaviour;
 
 		/**
-		 * The problem matchers attached to the task.
+		 * The problem matchers attached to the task. Defaults to an empty
+		 * array.
 		 */
-		readonly problemMatchers?: ProblemMatcher[];
+		problemMatchers: ProblemMatcher[];
 	}
 
 	export type Task = ProcessTask | ShellTask;

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

@@ -208,11 +208,11 @@ namespace RevealKind {
 }
 
 namespace TerminalBehaviour {
-	export function from(value: vscode.TerminalBehaviour): { showOutput: TaskSystem.ShowOutput } {
+	export function from(value: vscode.TerminalBehaviour): { showOutput: TaskSystem.ShowOutput, echo: boolean } {
 		if (value === void 0 || value === null) {
-			return { showOutput: TaskSystem.ShowOutput.Always };
+			return { showOutput: TaskSystem.ShowOutput.Always, echo: false };
 		}
-		return { showOutput: RevealKind.from(value.reveal) };
+		return { showOutput: RevealKind.from(value.reveal), echo: !!value.echo };
 	}
 }
 
@@ -303,13 +303,14 @@ namespace Tasks {
 		if (command === void 0) {
 			return undefined;
 		}
-		let outputChannel = TerminalBehaviour.from(task.terminal);
+		let behaviour = TerminalBehaviour.from(task.terminal);
+		command.echo = behaviour.echo;
 		let result: TaskSystem.Task = {
 			_id: uuidMap.getUUID(task.identifier),
 			name: task.name,
 			identifier: task.identifier,
 			command: command,
-			showOutput: outputChannel.showOutput,
+			showOutput: behaviour.showOutput,
 			isBackground: !!task.isBackground,
 			suppressTaskName: true,
 			problemMatchers: ProblemMatcher.from(task.problemMatchers)

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

@@ -992,28 +992,68 @@ export class BaseTask {
 
 	private _name: string;
 	private _problemMatchers: vscode.ProblemMatcher[];
-
-	public isBackground: boolean;
-	public identifier: string;
-	public terminal: vscode.TerminalBehaviour;
+	private _identifier: string;
+	private _isBackground: boolean;
+	private _terminal: vscode.TerminalBehaviour;
 
 	constructor(name: string, problemMatchers: vscode.ProblemMatcher[]) {
 		if (typeof name !== 'string') {
 			throw illegalArgument('name');
 		}
 		this._name = name;
-		this.identifier = name;
-		this._problemMatchers = problemMatchers;
-		this.isBackground = false;
+		this._identifier = name;
+		this._problemMatchers = problemMatchers || [];
+		this._isBackground = false;
+		this._terminal = Object.create(null);
+	}
+
+	get identifier(): string {
+		return this._identifier;
+	}
+
+	set identifier(value: string) {
+		if (typeof name !== 'string') {
+			throw illegalArgument('identifier');
+		}
+		this._identifier = value;
 	}
 
 	get name(): string {
 		return this._name;
 	}
 
+	get isBackground(): boolean {
+		return this._isBackground;
+	}
+
+	set isBackground(value: boolean) {
+		if (value !== true && value !== false) {
+			value = false;
+		}
+		this._isBackground = value;
+	}
+
+	get terminal(): vscode.TerminalBehaviour {
+		return this._terminal;
+	}
+
+	set terminal(value: vscode.TerminalBehaviour) {
+		if (value === void 0 || value === null) {
+			value = Object.create(null);
+		}
+		this._terminal = value;
+	}
+
 	get problemMatchers(): vscode.ProblemMatcher[] {
 		return this._problemMatchers;
 	}
+
+	set problemMatchers(value: vscode.ProblemMatcher[]) {
+		if (!Array.isArray(value)) {
+			value = [];
+		}
+		this._problemMatchers = value;
+	}
 }
 
 namespace ProblemMatcher {
@@ -1027,9 +1067,8 @@ namespace ProblemMatcher {
 export class ProcessTask extends BaseTask {
 
 	private _process: string;
-
-	public args: string[];
-	public options: vscode.ProcessOptions;
+	private _args: string[];
+	private _options: vscode.ProcessOptions;
 
 	private static parseArguments(restArgs: any[]): { args: string[]; options: vscode.ProcessOptions; problemMatchers: vscode.ProblemMatcher[] } {
 		let args: string[] = [];
@@ -1066,20 +1105,41 @@ export class ProcessTask extends BaseTask {
 		let { args, options, problemMatchers } = ProcessTask.parseArguments(rest);
 		super(name, problemMatchers);
 		this._process = process;
-		this.args = args;
-		this.options = options;
+		this._args = args;
+		this._options = options || Object.create(null);
 	}
 
 	get process(): string {
 		return this._process;
 	}
+
+	get args(): string[] {
+		return this._args;
+	}
+
+	set args(value: string[]) {
+		if (!Array.isArray(value)) {
+			value = [];
+		}
+		this._args = value;
+	}
+
+	get options(): vscode.ProcessOptions {
+		return this._options;
+	}
+
+	set options(value: vscode.ProcessOptions) {
+		if (value === void 0 || value === null) {
+			value = Object.create(null);
+		}
+		this._options = value;
+	}
 }
 
 export class ShellTask extends BaseTask {
 
 	private _commandLine: string;
-
-	public options: vscode.ShellOptions;
+	private _options: vscode.ShellOptions;
 
 	private static parseArguments(restArgs: any[]): { options: vscode.ShellOptions; problemMatchers: vscode.ProblemMatcher[] } {
 		let options: vscode.ShellOptions = undefined;
@@ -1109,10 +1169,21 @@ export class ShellTask extends BaseTask {
 
 		super(name, problemMatchers);
 		this._commandLine = commandLine;
-		this.options = options;
+		this._options = options || Object.create(null);
 	}
 
 	get commandLine(): string {
 		return this._commandLine;
 	}
+
+	get options(): vscode.ShellOptions {
+		return this._options;
+	}
+
+	set options(value: vscode.ShellOptions) {
+		if (value === void 0 || value === null) {
+			value = Object.create(null);
+		}
+		this._options = value;
+	}
 }
\ No newline at end of file

src/vs/workbench/parts/tasks/electron-browser/terminalTaskSystem.ts

@@ -370,6 +370,9 @@ export class TerminalTaskSystem extends EventEmitter implements ITaskSystem {
 			});
 			shellArgs.push(commandLine);
 			shellLaunchConfig.args = Platform.isWindows ? shellArgs.join(' ') : shellArgs;
+			if (task.command.echo) {
+				shellLaunchConfig.initialText = `> ${commandLine}`;
+			}
 		} else {
 			let cwd = options && options.cwd ? options.cwd : process.cwd();
 			// On Windows executed process must be described absolute. Since we allowed command without an
@@ -381,6 +384,18 @@ export class TerminalTaskSystem extends EventEmitter implements ITaskSystem {
 				args,
 				waitOnExit
 			};
+			if (task.command.echo) {
+				let getArgsToEcho = (args: string | string[]): string => {
+					if (!args || args.length === 0) {
+						return '';
+					}
+					if (Types.isString(args)) {
+						return args;
+					}
+					return args.join(' ');
+				};
+				shellLaunchConfig.initialText = `> ${shellLaunchConfig.executable} ${getArgsToEcho(shellLaunchConfig.args)}`;
+			}
 		}
 		if (options.cwd) {
 			shellLaunchConfig.cwd = options.cwd;