make changeLanguage return a TextDocument, #1800

Author: jrieken

src/vs/vscode.proposed.d.ts

@@ -16,7 +16,7 @@ declare module 'vscode' {
 		/**
 		 *
 		 */
-		export function changeLanguage(document: TextDocument, languageId: string): Thenable<void>;
+		export function changeLanguage(document: TextDocument, languageId: string): Thenable<TextDocument>;
 	}
 
 	//#region Joh - read/write in chunks

src/vs/workbench/api/node/extHost.api.impl.ts

@@ -138,7 +138,7 @@ export function createApiFactory(
 	const extHostDialogs = new ExtHostDialogs(rpcProtocol);
 	const extHostStatusBar = new ExtHostStatusBar(rpcProtocol);
 	const extHostOutputService = new ExtHostOutputService(initData.logsLocation, rpcProtocol);
-	const extHostLanguages = new ExtHostLanguages(rpcProtocol);
+	const extHostLanguages = new ExtHostLanguages(rpcProtocol, extHostDocuments);
 
 	// Register an output channel for exthost log
 	extHostOutputService.createOutputChannelFromLogFile(localize('extensionsLog', "Extension Host"), extHostLogService.logFile);
@@ -269,7 +269,7 @@ export function createApiFactory(
 			getLanguages(): Thenable<string[]> {
 				return extHostLanguages.getLanguages();
 			},
-			changeLanguage(document: vscode.TextDocument, languageId: string): Thenable<void> {
+			changeLanguage(document: vscode.TextDocument, languageId: string): Thenable<vscode.TextDocument> {
 				checkProposedApiEnabled(extension);
 				return extHostLanguages.changeLanguage(document.uri, languageId);
 			},

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

@@ -6,21 +6,28 @@
 
 import { MainContext, MainThreadLanguagesShape, IMainContext } from './extHost.protocol';
 import * as vscode from 'vscode';
+import { ExtHostDocuments } from 'vs/workbench/api/node/extHostDocuments';
 
 export class ExtHostLanguages {
 
-	private _proxy: MainThreadLanguagesShape;
+	private readonly _proxy: MainThreadLanguagesShape;
+	private readonly _documents: ExtHostDocuments;
 
 	constructor(
-		mainContext: IMainContext
+		mainContext: IMainContext,
+		documents: ExtHostDocuments
 	) {
 		this._proxy = mainContext.getProxy(MainContext.MainThreadLanguages);
+		this._documents = documents;
 	}
 
 	getLanguages(): Thenable<string[]> {
 		return this._proxy.$getLanguages();
 	}
-	changeLanguage(documentUri: vscode.Uri, languageId: string): Thenable<void> {
-		return this._proxy.$changeLanguage(documentUri, languageId);
+
+	changeLanguage(uri: vscode.Uri, languageId: string): Thenable<vscode.TextDocument> {
+		return this._proxy.$changeLanguage(uri, languageId).then(() => {
+			return this._documents.getDocumentData(uri).document;
+		});
 	}
 }