fixup! TF-4224 Reduce ReDoS vulnerability

core/lib/presentation/utils/html_transformer/base/dom_transformer.dart

@@ -2,6 +2,7 @@
 import 'package:core/data/network/dio_client.dart';
 import 'package:core/utils/app_logger.dart';
 import 'package:dartz/dartz.dart';
+import 'package:flutter/widgets.dart' show visibleForTesting;
 import 'package:html/dom.dart';
 
 /// Transforms the HTML DOM.
@@ -11,6 +12,9 @@ abstract class DomTransformer {
 
   static final _backgroundImageRegex = RegExp(r'''\bbackground-image\s*:\s*url\(\s*['"]?([^' ")]+)['"]?\s*\)''');
 
+  @visibleForTesting
+  static RegExp get backgroundImageRegex => _backgroundImageRegex;
+
   /// Uses the `DOM` [document] to transform the `document`.
   ///
   /// All changes will be visible to subsequent transformers.

core/lib/presentation/utils/html_transformer/dom/normalize_line_height_in_style_transformer.dart

@@ -1,6 +1,7 @@
 import 'package:core/data/network/dio_client.dart';
 import 'package:core/presentation/utils/html_transformer/base/dom_transformer.dart';
 import 'package:core/utils/app_logger.dart';
+import 'package:flutter/widgets.dart' show visibleForTesting;
 import 'package:html/dom.dart';
 
 class NormalizeLineHeightInStyleTransformer extends DomTransformer {
@@ -15,6 +16,9 @@ class NormalizeLineHeightInStyleTransformer extends DomTransformer {
     caseSensitive: false,
   );
 
+  @visibleForTesting
+  static RegExp get lineHeightPattern => _lineHeightPattern;
+
   @override
   Future<void> process({
     required Document document,