rephrased documentation and split up tests for web and mobile platform.

flutter/lib/src/sentry_flutter_options.dart

@@ -145,15 +145,15 @@ class SentryFlutterOptions extends SentryOptions {
 
   /// (Web only) Events only occurring on these Urls will be handled and sent to sentry.
   /// If an empty list is used, the SDK will send all errors.
-  /// To use regex add the `^` and the `$` to the string.
+  /// `allowUrls` uses regex for the matching.
   ///
   /// If used on a platform other than Web, this setting will be ignored.
   List<String> allowUrls = [];
 
   /// (Web only) Events occurring on these Urls will be ignored and are not sent to sentry.
   /// If an empty list is used, the SDK will send all errors.
+  /// `denyUrls` uses regex for the matching.
   /// In combination with `allowUrls` you can block subdomains of the domains listed in `allowUrls`.
-  /// To use regex add the `^` and the `$` to the string.
   ///
   /// If used on a platform other than Web, this setting will be ignored.
   List<String> denyUrls = [];

flutter/test/event_processor/url_filter/io_filter_event_processor_test.dart

@@ -0,0 +1,39 @@
+@TestOn('vm')
+library flutter_test;
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:sentry_flutter/sentry_flutter.dart';
+import 'package:sentry_flutter/src/event_processor/url_filter/url_filter_event_processor.dart';
+
+void main() {
+  group("ignore allowUrls and denyUrls for non Web", () {
+    late Fixture fixture;
+
+    setUp(() async {
+      fixture = Fixture();
+    });
+
+    test('returns the event and ignore allowUrls and denyUrls for non Web',
+        () async {
+      SentryEvent? event = SentryEvent(
+        request: SentryRequest(
+          url: 'another.url/for/a/special/test/testing/this-feature',
+        ),
+      );
+      fixture.options.allowUrls = ["^this.is/.*\$"];
+      fixture.options.denyUrls = ["special"];
+
+      var eventProcessor = fixture.getSut();
+      event = await eventProcessor.apply(event, Hint());
+
+      expect(event, isNotNull);
+    });
+  });
+}
+
+class Fixture {
+  SentryFlutterOptions options = SentryFlutterOptions();
+  UrlFilterEventProcessor getSut() {
+    return UrlFilterEventProcessor(options);
+  }
+}

flutter/test/event_processor/url_filter/web_url_filter_event_processor_test.dart

@@ -0,0 +1,149 @@
+@TestOn('browser')
+library flutter_test;
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:sentry_flutter/sentry_flutter.dart';
+import 'package:sentry_flutter/src/event_processor/url_filter/url_filter_event_processor.dart';
+
+// can be tested on command line with
+// `flutter test --platform=chrome test/event_processor/url_filter/web_url_filter_event_processor_test.dart`
+void main() {
+  group(UrlFilterEventProcessor, () {
+    late Fixture fixture;
+
+    setUp(() {
+      fixture = Fixture();
+    });
+
+    test('returns event if no allowUrl and no denyUrl is set', () async {
+      SentryEvent? event = SentryEvent(
+        request: SentryRequest(
+          url: 'foo.bar',
+        ),
+      );
+
+      var eventProcessor = fixture.getSut();
+      event = await eventProcessor.apply(event, Hint());
+
+      expect(event, isNotNull);
+    });
+
+    test('returns null if allowUrl is set and does not match with url',
+        () async {
+      SentryEvent? event = SentryEvent(
+        request: SentryRequest(
+          url: 'foo.bar',
+        ),
+      );
+      fixture.options.allowUrls = ["another.url"];
+
+      var eventProcessor = fixture.getSut();
+      event = await eventProcessor.apply(event, Hint());
+
+      expect(event, isNull);
+    });
+
+    test('returns event if allowUrl is set and does partially match with url',
+        () async {
+      SentryEvent? event = SentryEvent(
+        request: SentryRequest(
+          url: 'foo.bar',
+        ),
+      );
+      fixture.options.allowUrls = ["bar"];
+
+      var eventProcessor = fixture.getSut();
+      event = await eventProcessor.apply(event, Hint());
+
+      expect(event, isNotNull);
+    });
+
+    test('returns event if denyUrl is set and does not match with url',
+        () async {
+      SentryEvent? event = SentryEvent(
+        request: SentryRequest(
+          url: 'foo.bar',
+        ),
+      );
+      fixture.options.denyUrls = ["another.url"];
+
+      var eventProcessor = fixture.getSut();
+      event = await eventProcessor.apply(event, Hint());
+
+      expect(event, isNotNull);
+    });
+
+    test('returns null if denyUrl is set and partially matches with url',
+        () async {
+      SentryEvent? event = SentryEvent(
+        request: SentryRequest(
+          url: 'foo.bar',
+        ),
+      );
+      fixture.options.denyUrls = ["bar"];
+
+      var eventProcessor = fixture.getSut();
+      event = await eventProcessor.apply(event, Hint());
+
+      expect(event, isNull);
+    });
+
+    test(
+        'returns null if it is part of the allowed domain, but blocked for subdomain',
+        () async {
+      SentryEvent? event = SentryEvent(
+        request: SentryRequest(
+          url: 'this.is/a/special/url/for-testing/this-feature',
+        ),
+      );
+      fixture.options.allowUrls = ["^this.is/.*\$"];
+      fixture.options.denyUrls = ["special"];
+
+      var eventProcessor = fixture.getSut();
+      event = await eventProcessor.apply(event, Hint());
+
+      expect(event, isNull);
+    });
+
+    test(
+        'returns event if it is part of the allowed domain, and not of the blocked for subdomain',
+        () async {
+      SentryEvent? event = SentryEvent(
+        request: SentryRequest(
+          url: 'this.is/a/test/url/for-testing/this-feature',
+        ),
+      );
+      fixture.options.allowUrls = ["^this.is/.*\$"];
+      fixture.options.denyUrls = ["special"];
+
+      var eventProcessor = fixture.getSut();
+      event = await eventProcessor.apply(event, Hint());
+
+      expect(event, isNotNull);
+    });
+
+    test(
+        'returns null if it is not part of the allowed domain, and not of the blocked for subdomain',
+        () async {
+      SentryEvent? event = SentryEvent(
+        request: SentryRequest(
+          url: 'another.url/for/a/test/testing/this-feature',
+        ),
+      );
+      fixture.options.allowUrls = ["^this.is/.*\$"];
+      fixture.options.denyUrls = ["special"];
+
+      var eventProcessor = fixture.getSut();
+      event = await eventProcessor.apply(event, Hint());
+
+      expect(event, isNull);
+    });
+  });
+}
+
+class Fixture {
+  SentryFlutterOptions options = SentryFlutterOptions();
+  UrlFilterEventProcessor getSut() {
+    return UrlFilterEventProcessor(options);
+  }
+}