change to static function

dart/lib/src/sentry_exception_factory.dart

@@ -58,12 +58,11 @@ class SentryExceptionFactory {
       }
     }
 
-    final stackTraceUtils = StackTraceUtils(throwable.toString());
     // if --obfuscate feature is enabled, 'type' won't be human readable.
     // https://flutter.dev/docs/deployment/obfuscate#caveat
     return SentryException(
       type: (throwable.runtimeType).toString(),
-      value: stackTraceUtils.removeStackStraceLines(),
+      value: StackTraceUtils.removeStackStraceLines(throwable.toString()),
       mechanism: mechanism,
       stackTrace: sentryStackTrace,
       throwable: throwable,

dart/lib/src/utils/stack_trace_utils.dart

@@ -2,19 +2,15 @@ import 'package:meta/meta.dart';
 
 @internal
 class StackTraceUtils {
-  StackTraceUtils(this.input);
-
-  final String input;
-
-  late final _stackStackTrace =
+  static final _stackStackTrace =
       RegExp(r'^#\d+.*\.dart:\d+:\d+\)$', multiLine: true);
-  late final _flutterStackTrace =
+  static final _flutterStackTrace =
       RegExp(r'^flutter:\s#\d+.*\.dart:\d+:\d+\)$', multiLine: true);
-  late final _obfuscatedStackTrace =
+  static final _obfuscatedStackTrace =
       RegExp(r'^#\d+.*\+0x\w+$', multiLine: true);
-  late final _multipleNewlines = RegExp(r'\n+');
+  static final _multipleNewlines = RegExp(r'\n+');
 
-  String removeStackStraceLines() {
+  static String removeStackStraceLines(String input) {
     return input
         .replaceAll(_stackStackTrace, '')
         .replaceAll(_flutterStackTrace, '')

dart/test/utils/stack_trace_utils_test.dart

@@ -2,12 +2,6 @@ import 'package:sentry/src/utils/stack_trace_utils.dart';
 import 'package:test/test.dart';
 
 void main() {
-  late Fixture fixture;
-
-  setUp(() {
-    fixture = Fixture();
-  });
-
   final dartStackTrace = '''
 randomPrefix
 #0      main (file:///Users/denis/Repos/other/dart-stacktrace/main.dart:2:20)
@@ -53,28 +47,22 @@ randomSuffix
   final cleanedUp = 'randomPrefix\nrandomSuffix';
 
   test('removes dart stack trace', () {
-    final sut = fixture.getSut(dartStackTrace);
-    expect(sut.removeStackStraceLines(), cleanedUp);
+    expect(StackTraceUtils.removeStackStraceLines(dartStackTrace), cleanedUp);
   });
 
   test('removes flutter stack trace', () {
-    final sut = fixture.getSut(flutterStackTrace);
-    expect(sut.removeStackStraceLines(), cleanedUp);
+    expect(
+        StackTraceUtils.removeStackStraceLines(flutterStackTrace), cleanedUp);
   });
 
   test('removes flutter obfuscated stack trace', () {
-    final sut = fixture.getSut(flutterObfuscatedStackTrace);
-    expect(sut.removeStackStraceLines(), cleanedUp);
+    expect(StackTraceUtils.removeStackStraceLines(flutterObfuscatedStackTrace),
+        cleanedUp);
   });
 
   test('removes stack trace with asynchronous suspension', () {
-    final sut = fixture.getSut(stackTraceWithAsyncSuspension);
-    expect(sut.removeStackStraceLines(), cleanedUp);
+    expect(
+        StackTraceUtils.removeStackStraceLines(stackTraceWithAsyncSuspension),
+        cleanedUp);
   });
 }
-
-class Fixture {
-  StackTraceUtils getSut(String input) {
-    return StackTraceUtils(input);
-  }
-}