From c8a8fc7ddd03005a9b59d53deabff1ae4f699dc7 Mon Sep 17 00:00:00 2001
From: Johannes Rieken <johannes.rieken@gmail.com>
Date: Thu, 2 Nov 2017 11:04:49 +0100
Subject: [PATCH] fix #37484

---
 .../vscode-api-tests/src/commands.test.ts      | 18 +++++++++++++++++-
 src/vs/workbench/api/node/extHost.protocol.ts  |  2 +-
 src/vs/workbench/api/node/extHostCommands.ts   |  9 ++++++---
 3 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/extensions/vscode-api-tests/src/commands.test.ts b/extensions/vscode-api-tests/src/commands.test.ts
index 0d92795d241..28d727bc1ca 100644
--- a/extensions/vscode-api-tests/src/commands.test.ts
+++ b/extensions/vscode-api-tests/src/commands.test.ts
@@ -56,6 +56,22 @@ suite('commands namespace tests', () => {
 		});
 	});
 
+	test('command with return-value', function () {
+
+		let registration = commands.registerCommand('t1', function () {
+			return new Set<number>().add(1).add(2);
+		});
+
+		return commands.executeCommand('t1', 'start').then(value => {
+			registration.dispose();
+
+			assert.ok(value instanceof Set);
+			assert.equal((<Set<number>>value).size, 2);
+			assert.equal((<Set<number>>value).has(1), true);
+			assert.equal((<Set<number>>value).has(2), true);
+		});
+	});
+
 	test('editorCommand with extra args', function () {
 
 		let args: IArguments;
@@ -134,4 +150,4 @@ suite('commands namespace tests', () => {
 
 		return Promise.all([a, b, c, d]);
 	});
-});
\ No newline at end of file
+});
diff --git a/src/vs/workbench/api/node/extHost.protocol.ts b/src/vs/workbench/api/node/extHost.protocol.ts
index ea75a41995c..89e8011b409 100644
--- a/src/vs/workbench/api/node/extHost.protocol.ts
+++ b/src/vs/workbench/api/node/extHost.protocol.ts
@@ -429,7 +429,7 @@ export interface MainThreadWindowShape extends IDisposable {
 // -- extension host
 
 export interface ExtHostCommandsShape {
-	$executeContributedCommand<T>(id: string, ...args: any[]): Thenable<T>;
+	$executeContributedCommand<T>(id: string, ...args: any[]): Thenable<void>;
 	$getContributedCommandHandlerDescriptions(): TPromise<{ [id: string]: string | ICommandHandlerDescription }>;
 }
 
diff --git a/src/vs/workbench/api/node/extHostCommands.ts b/src/vs/workbench/api/node/extHostCommands.ts
index 774d71f8e26..ca82afcef48 100644
--- a/src/vs/workbench/api/node/extHostCommands.ts
+++ b/src/vs/workbench/api/node/extHostCommands.ts
@@ -74,7 +74,7 @@ export class ExtHostCommands implements ExtHostCommandsShape {
 		if (this._commands.has(id)) {
 			// we stay inside the extension host and support
 			// to pass any kind of parameters around
-			return this.$executeContributedCommand<T>(id, ...args);
+			return this._executeContributedCommand<T>(id, ...args);
 
 		} else {
 			// automagically convert some argument types
@@ -96,10 +96,9 @@ export class ExtHostCommands implements ExtHostCommandsShape {
 
 			return this._proxy.$executeCommand<T>(id, args);
 		}
-
 	}
 
-	$executeContributedCommand<T>(id: string, ...args: any[]): Thenable<T> {
+	private _executeContributedCommand<T>(id: string, ...args: any[]): Thenable<T> {
 		let command = this._commands.get(id);
 		if (!command) {
 			return TPromise.wrapError<T>(new Error(`Contributed command '${id}' does not exist.`));
@@ -133,6 +132,10 @@ export class ExtHostCommands implements ExtHostCommandsShape {
 		}
 	}
 
+	$executeContributedCommand<T>(id: string, ...args: any[]): Thenable<void> {
+		return this._executeContributedCommand(id, ...args).then(result => void 0);
+	}
+
 	getCommands(filterUnderscoreCommands: boolean = false): Thenable<string[]> {
 		return this._proxy.$getCommands().then(result => {
 			if (filterUnderscoreCommands) {