fix #65412

src/vs/editor/contrib/snippet/snippetParser.ts

@@ -930,7 +930,7 @@ export class SnippetParser {
 
 			let escaped: string;
 			if (escaped = this._accept(TokenType.Backslash, true)) {
-				escaped = this._accept(TokenType.Forwardslash, true) || escaped;
+				escaped = this._accept(TokenType.Backslash, true) || this._accept(TokenType.Forwardslash, true) || escaped;
 				transform.appendChild(new Text(escaped));
 				continue;
 			}

src/vs/editor/contrib/snippet/test/snippetParser.test.ts

@@ -748,4 +748,10 @@ suite('SnippetParser', () => {
 		let [, , clone] = snippet.children;
 		assertParent(clone);
 	});
+
+	test('Backspace can\'t be escaped in snippet variable transforms #65412', function () {
+
+		let snippet = new SnippetParser().parse('namespace ${TM_DIRECTORY/[\\/]/\\\\/g};');
+		assertMarker(snippet, Text, Variable, Text);
+	});
 });