fix #76620

src/vs/base/test/node/stream/fixtures/file.css

-/*---------------------------------------------------------------------------------------------
- *  Copyright (c) Microsoft Corporation. All rights reserved.
- *  Licensed under the MIT License. See License.txt in the project root for license information.
- *--------------------------------------------------------------------------------------------*/
-
-/*----------------------------------------------------------
-The base color for this template is #5c87b2. If you'd like
-to use a different color start by replacing all instances of
-#5c87b2 with your new color.
-----------------------------------------------------------*/
-body
-{
-    background-color: #5c87b2;
-    font-size: .75em;
-    font-family: Segoe UI, Verdana, Helvetica, Sans-Serif;
-    margin: 8px;
-    padding: 0;
-    color: #696969;
-}
-
-h1, h2, h3, h4, h5, h6
-{
-    color: #000;
-    font-size: 40px;
-    margin: 0px;
-}
-
-textarea 
-{
-   font-family: Consolas
-}
-
-#results 
-{
-    margin-top: 2em;
-    margin-left: 2em;
-    color: black;
-    font-size: medium;
-}
-

src/vs/base/test/node/stream/stream.test.ts

-/*---------------------------------------------------------------------------------------------
- *  Copyright (c) Microsoft Corporation. All rights reserved.
- *  Licensed under the MIT License. See License.txt in the project root for license information.
- *--------------------------------------------------------------------------------------------*/
-
-import * as assert from 'assert';
-
-import * as stream from 'vs/base/node/stream';
-import { getPathFromAmdModule } from 'vs/base/common/amd';
-
-suite('Stream', () => {
-	test('readToMatchingString - ANSI', async () => {
-		const file = getPathFromAmdModule(require, './fixtures/file.css');
-
-		const result = await stream.readToMatchingString(file, '\n', 10, 100);
-
-		// \r may be present on Windows
-		assert.equal(result!.replace('\r', ''), '/*---------------------------------------------------------------------------------------------');
-	});
-
-	test('readToMatchingString - empty', async () => {
-		const file = getPathFromAmdModule(require, './fixtures/empty.txt');
-
-		const result = await stream.readToMatchingString(file, '\n', 10, 100);
-		assert.equal(result, null);
-	});
-});

src/vs/workbench/services/backup/node/backupFileService.ts

@@ -12,7 +12,6 @@ import { equals, deepClone } from 'vs/base/common/objects';
 import { ResourceQueue } from 'vs/base/common/async';
 import { IBackupFileService, IResolvedBackup } from 'vs/workbench/services/backup/common/backup';
 import { IFileService } from 'vs/platform/files/common/files';
-import { readToMatchingString } from 'vs/base/node/stream';
 import { ITextSnapshot } from 'vs/editor/common/model';
 import { createTextBufferFactoryFromStream, createTextBufferFactoryFromSnapshot } from 'vs/editor/common/model/textModel';
 import { keys, ResourceMap } from 'vs/base/common/map';
@@ -278,7 +277,7 @@ class BackupFileServiceImpl implements IBackupFileService {
 		const model = await this.ready;
 
 		const backups = await Promise.all(model.get().map(async fileBackup => {
-			const backupPreamble = await readToMatchingString(fileBackup.fsPath, BackupFileServiceImpl.PREAMBLE_END_MARKER, BackupFileServiceImpl.PREAMBLE_MAX_LENGTH / 5, BackupFileServiceImpl.PREAMBLE_MAX_LENGTH);
+			const backupPreamble = await this.readToMatchingString(fileBackup, BackupFileServiceImpl.PREAMBLE_END_MARKER, BackupFileServiceImpl.PREAMBLE_MAX_LENGTH);
 			if (!backupPreamble) {
 				return undefined;
 			}
@@ -298,6 +297,17 @@ class BackupFileServiceImpl implements IBackupFileService {
 		return coalesce(backups);
 	}
 
+	private async readToMatchingString(file: URI, matchingString: string, maximumBytesToRead: number): Promise<string> {
+		const contents = (await this.fileService.readFile(file, { length: maximumBytesToRead })).value.toString();
+
+		const newLineIndex = contents.indexOf(matchingString);
+		if (newLineIndex >= 0) {
+			return contents.substr(0, newLineIndex);
+		}
+
+		throw new Error(`Could not find ${matchingString} in first ${maximumBytesToRead} bytes of ${file}`);
+	}
+
 	async resolveBackupContent<T extends object>(backup: URI): Promise<IResolvedBackup<T>> {
 
 		// Metadata extraction