Support running terminals in background

Part of #72518

src/vs/vscode.proposed.d.ts

@@ -1254,6 +1254,16 @@ declare module 'vscode' {
 
 	//#region Terminal
 
+	export interface TerminalOptions {
+		/**
+		 * When enabled the terminal will run the process as normal but not be surfaced
+		 * to the user until `Terminal.show` is called. The typical usage for this
+		 * is when you need to run something that may need interactivity but only
+		 * want to tell the user about it when interaction is needed.
+		 */
+		runInBackground?: boolean;
+	}
+
 	/**
 	 * An [event](#Event) which fires when a [Terminal](#Terminal)'s dimensions change.
 	 */

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

@@ -62,7 +62,7 @@ export class MainThreadTerminalService implements MainThreadTerminalServiceShape
 		// when the extension host process goes down ?
 	}
 
-	public $createTerminal(name?: string, shellPath?: string, shellArgs?: string[] | string, cwd?: string | UriComponents, env?: { [key: string]: string }, waitOnExit?: boolean, strictEnv?: boolean): Promise<{ id: number, name: string }> {
+	public $createTerminal(name?: string, shellPath?: string, shellArgs?: string[] | string, cwd?: string | UriComponents, env?: { [key: string]: string }, waitOnExit?: boolean, strictEnv?: boolean, runInBackground?: boolean): Promise<{ id: number, name: string }> {
 		const shellLaunchConfig: IShellLaunchConfig = {
 			name,
 			executable: shellPath,
@@ -71,7 +71,8 @@ export class MainThreadTerminalService implements MainThreadTerminalServiceShape
 			waitOnExit,
 			ignoreConfigurationCwd: true,
 			env,
-			strictEnv
+			strictEnv,
+			runInBackground
 		};
 		const terminal = this.terminalService.createTerminal(shellLaunchConfig);
 		return Promise.resolve({

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

@@ -390,7 +390,7 @@ export interface MainThreadProgressShape extends IDisposable {
 }
 
 export interface MainThreadTerminalServiceShape extends IDisposable {
-	$createTerminal(name?: string, shellPath?: string, shellArgs?: string[] | string, cwd?: string | UriComponents, env?: { [key: string]: string | null }, waitOnExit?: boolean, strictEnv?: boolean): Promise<{ id: number, name: string }>;
+	$createTerminal(name?: string, shellPath?: string, shellArgs?: string[] | string, cwd?: string | UriComponents, env?: { [key: string]: string | null }, waitOnExit?: boolean, strictEnv?: boolean, runInBackground?: boolean): Promise<{ id: number, name: string }>;
 	$createTerminalRenderer(name: string): Promise<number>;
 	$dispose(terminalId: number): void;
 	$hide(terminalId: number): void;

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

@@ -114,9 +114,10 @@ export class ExtHostTerminal extends BaseExtHostTerminal implements vscode.Termi
 		cwd?: string | URI,
 		env?: { [key: string]: string | null },
 		waitOnExit?: boolean,
-		strictEnv?: boolean
+		strictEnv?: boolean,
+		runInBackground?: boolean
 	): void {
-		this._proxy.$createTerminal(this._name, shellPath, shellArgs, cwd, env, waitOnExit, strictEnv).then(terminal => {
+		this._proxy.$createTerminal(this._name, shellPath, shellArgs, cwd, env, waitOnExit, strictEnv, runInBackground).then(terminal => {
 			this._name = terminal.name;
 			this._runQueuedRequests(terminal.id);
 		});
@@ -308,7 +309,7 @@ export class ExtHostTerminalService implements ExtHostTerminalServiceShape {
 
 	public createTerminalFromOptions(options: vscode.TerminalOptions): vscode.Terminal {
 		const terminal = new ExtHostTerminal(this._proxy, options.name);
-		terminal.create(options.shellPath, options.shellArgs, options.cwd, options.env, /*options.waitOnExit*/ undefined, options.strictEnv);
+		terminal.create(options.shellPath, options.shellArgs, options.cwd, options.env, /*options.waitOnExit*/ undefined, options.strictEnv, options.runInBackground);
 		this._terminals.push(terminal);
 		return terminal;
 	}

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

@@ -50,6 +50,14 @@ export abstract class TerminalService extends CommonTerminalService implements I
 	}
 
 	public createTerminal(shell: IShellLaunchConfig = {}): ITerminalInstance {
+		if (shell.runInBackground) {
+			// TODO: When show is triggered, create a TerminalTab for this instance
+			return this.createInstance(this._terminalFocusContextKey,
+				this.configHelper,
+				undefined,
+				shell,
+				true);
+		}
 		const terminalTab = this._instantiationService.createInstance(TerminalTab,
 			this._terminalFocusContextKey,
 			this.configHelper,

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

@@ -192,6 +192,14 @@ export interface IShellLaunchConfig {
 	 * provided as nothing will be inherited from the process or any configuration.
 	 */
 	strictEnv?: boolean;
+
+	/**
+	 * When enabled the terminal will run the process as normal but not be surfaced to the user
+	 * until `Terminal.show` is called. The typical usage for this is when you need to run something
+	 * that may need interactivity but only want to tell the user about it when interaction is
+	 * needed.
+	 */
+	runInBackground?: boolean;
 }
 
 export interface ITerminalService {