[folding] Cannot read property 'length' of undefined. Fixes #46171

extensions/html-language-features/server/src/modes/javascriptMode.ts

@@ -292,9 +292,9 @@ export function getJavascriptMode(documentRegions: LanguageModelCache<HTMLDocume
 				let endLine = curr.end.line;
 				if (startLine < endLine && startLine >= rangeStartLine && endLine < rangeEndLine) {
 					let foldingRange: FoldingRange = { startLine, endLine };
-					let match = document.getText(curr).match(/^\s*\/(\/\s*#(?:end)?region\b)|([\*\/])/);
+					let match = document.getText(curr).match(/^\s*\/(?:(\/\s*#(?:end)?region\b)|(\*|\/))/);
 					if (match) {
-						foldingRange.type = match[1].length ? FoldingRangeType.Region : FoldingRangeType.Comment;
+						foldingRange.type = match[1] ? FoldingRangeType.Region : FoldingRangeType.Comment;
 					}
 					ranges.push(foldingRange);
 				}

extensions/html-language-features/server/src/test/folding.test.ts

@@ -130,7 +130,7 @@ suite('Object Folding', () => {
 			/* 6*/'  };',
 			/* 7*/'</script>',
 			/* 8*/'<script>',
-			/* 9*/'  test(() => {',
+			/* 9*/'  test(() => { // hello',
 			/*10*/'    f();',
 			/*11*/'  });',
 			/*12*/'</script>',
@@ -206,7 +206,7 @@ suite('Object Folding', () => {
 			/*2*/'</div>',
 		];
 		assertRanges(input, [r(0, 1)]);
-	});	
+	});
 
 	test('Fold intersecting region', () => {
 		let input = [
@@ -218,7 +218,7 @@ suite('Object Folding', () => {
 			/*5*/'<!-- #endregion -->',
 		];
 		assertRanges(input, [r(0, 3)]);
-	});	
+	});
 
 
 	test('Test limit', () => {