chore: Allow overriding the route filtering using a ctor param `route…

…Filter` (#95)

.github/workflows/ci.yml

@@ -32,6 +32,9 @@ jobs:
         working-directory: ./example
         run: flutter pub get
 
+      - name: Test
+        run: flutter test
+
       - name: Build iOS
         working-directory: ./example
         run: flutter build ios --simulator --no-codesign

CHANGELOG.md

@@ -1,5 +1,13 @@
 ## Next
 
+- chore: Allow overriding the route filtering using a ctor param `routeFilter` ([#95](https://github.com/PostHog/posthog-flutter/pull/95))
+
+```dart
+bool myRouteFilter(Route<dynamic>? route) =>
+        route is PageRoute || route is OverlayRoute;
+final observer = PosthogObserver(routeFilter: myRouteFilter);
+```
+
 ## 4.3.0
 
 - add PrivacyInfo ([#94](https://github.com/PostHog/posthog-flutter/pull/94))

lib/src/posthog.dart

@@ -4,7 +4,7 @@ class Posthog {
   static PosthogFlutterPlatformInterface get _posthog =>
       PosthogFlutterPlatformInterface.instance;
 
-  static final Posthog _instance = Posthog._internal();
+  static final _instance = Posthog._internal();
 
   factory Posthog() {
     return _instance;

lib/src/posthog_observer.dart

@@ -4,47 +4,76 @@ import 'posthog.dart';
 
 typedef ScreenNameExtractor = String? Function(RouteSettings settings);
 
+/// [PostHogRouteFilter] allows to filter out routes that should not be tracked.
+///
+/// By default, only [PageRoute]s are tracked.
+typedef PostHogRouteFilter = bool Function(Route<dynamic>? route);
+
 String? defaultNameExtractor(RouteSettings settings) => settings.name;
 
-class PosthogObserver extends RouteObserver<PageRoute<dynamic>> {
-  PosthogObserver({ScreenNameExtractor nameExtractor = defaultNameExtractor})
-      : _nameExtractor = nameExtractor;
+bool defaultPostHogRouteFilter(Route<dynamic>? route) => route is PageRoute;
+
+class PosthogObserver extends RouteObserver<ModalRoute<dynamic>> {
+  PosthogObserver(
+      {ScreenNameExtractor nameExtractor = defaultNameExtractor,
+      PostHogRouteFilter routeFilter = defaultPostHogRouteFilter})
+      : _nameExtractor = nameExtractor,
+        _routeFilter = routeFilter;
 
   final ScreenNameExtractor _nameExtractor;
 
-  void _sendScreenView(PageRoute<dynamic> route) {
-    String? screenName = _nameExtractor(route.settings);
-    if (screenName != null) {
+  final PostHogRouteFilter _routeFilter;
+
+  bool _isTrackeableRoute(String? name) {
+    return name != null && name.trim().isNotEmpty;
+  }
+
+  void _sendScreenView(Route<dynamic>? route) {
+    if (route == null) {
+      return;
+    }
+
+    var screenName = _nameExtractor(route.settings);
+    if (_isTrackeableRoute(screenName)) {
       // if the screen name is the root route, we send it as root ("/") instead of only "/"
       if (screenName == '/') {
         screenName = 'root (\'/\')';
       }
 
-      Posthog().screen(screenName: screenName);
+      Posthog().screen(screenName: screenName!);
     }
   }
 
   @override
   void didPush(Route<dynamic> route, Route<dynamic>? previousRoute) {
     super.didPush(route, previousRoute);
-    if (route is PageRoute) {
-      _sendScreenView(route);
+
+    if (!_routeFilter(route)) {
+      return;
     }
+
+    _sendScreenView(route);
   }
 
   @override
   void didReplace({Route<dynamic>? newRoute, Route<dynamic>? oldRoute}) {
     super.didReplace(newRoute: newRoute, oldRoute: oldRoute);
-    if (newRoute is PageRoute) {
-      _sendScreenView(newRoute);
+
+    if (!_routeFilter(newRoute)) {
+      return;
     }
+
+    _sendScreenView(newRoute);
   }
 
   @override
   void didPop(Route<dynamic> route, Route<dynamic>? previousRoute) {
     super.didPop(route, previousRoute);
-    if (previousRoute is PageRoute && route is PageRoute) {
-      _sendScreenView(previousRoute);
+
+    if (!_routeFilter(previousRoute)) {
+      return;
     }
+
+    _sendScreenView(previousRoute);
   }
 }

pubspec.yaml

@@ -18,7 +18,9 @@ dependencies:
   plugin_platform_interface: ^2.0.2
 
 dev_dependencies:
-  flutter_lints: ^2.0.0
+  flutter_lints: ^3.0.0
+  flutter_test:
+    sdk: flutter
 
 # For information on the generic Dart part of this file, see the
 # following page: https://dart.dev/tools/pub/pubspec

test/posthog_flutter_platform_interface_fake.dart

@@ -0,0 +1,13 @@
+import 'package:posthog_flutter/src/posthog_flutter_platform_interface.dart';
+
+class PosthogFlutterPlatformFake extends PosthogFlutterPlatformInterface {
+  String? screenName;
+
+  @override
+  Future<void> screen({
+    required String screenName,
+    Map<String, Object>? properties,
+  }) async {
+    this.screenName = screenName;
+  }
+}

test/posthog_observer_test.dart

@@ -0,0 +1,115 @@
+import 'package:flutter/widgets.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:posthog_flutter/src/posthog_flutter_io.dart';
+import 'package:posthog_flutter/src/posthog_flutter_platform_interface.dart';
+import 'package:posthog_flutter/src/posthog_observer.dart';
+
+import 'posthog_flutter_platform_interface_fake.dart';
+
+void main() {
+  PageRoute<dynamic> route(RouteSettings? settings) => PageRouteBuilder<void>(
+        pageBuilder: (_, __, ___) => Container(),
+        settings: settings,
+      );
+
+  final fake = PosthogFlutterPlatformFake();
+
+  setUp(() {
+    TestWidgetsFlutterBinding.ensureInitialized();
+    PosthogFlutterPlatformInterface.instance = fake;
+  });
+
+  tearDown(() {
+    fake.screenName = null;
+    PosthogFlutterPlatformInterface.instance = PosthogFlutterIO();
+  });
+
+  PosthogObserver getSut(
+      {ScreenNameExtractor nameExtractor = defaultNameExtractor,
+      PostHogRouteFilter routeFilter = defaultPostHogRouteFilter}) {
+    return PosthogObserver(
+        nameExtractor: nameExtractor, routeFilter: routeFilter);
+  }
+
+  test('returns current route name', () {
+    final currentRoute = route(const RouteSettings(name: 'Current Route'));
+
+    final sut = getSut();
+    sut.didPush(currentRoute, null);
+
+    expect(fake.screenName, 'Current Route');
+  });
+
+  test('returns overriden route name', () {
+    final currentRoute = route(const RouteSettings(name: 'Current Route'));
+
+    String? nameExtractor(RouteSettings settings) => 'overriden';
+
+    final sut = getSut(nameExtractor: nameExtractor);
+    sut.didPush(currentRoute, null);
+
+    expect(fake.screenName, 'overriden');
+  });
+
+  test('returns overriden root route name', () {
+    final currentRoute = route(const RouteSettings(name: '/'));
+
+    final sut = getSut();
+    sut.didPush(currentRoute, null);
+
+    expect(fake.screenName, 'root (\'/\')');
+  });
+
+  test('does not capture not named routes', () {
+    final currentRoute = route(const RouteSettings(name: null));
+
+    final sut = getSut();
+    sut.didPush(currentRoute, null);
+
+    expect(fake.screenName, null);
+  });
+
+  test('does not capture blank routes', () {
+    final currentRoute = route(const RouteSettings(name: '  '));
+
+    final sut = getSut();
+    sut.didPush(currentRoute, null);
+
+    expect(fake.screenName, null);
+  });
+
+  test('does not capture filtered routes', () {
+    // CustomOverlawRoute isn't a PageRoute
+    final overlayRoute = CustomOverlawRoute(
+      settings: const RouteSettings(name: 'Overlay Route'),
+    );
+
+    final sut = getSut();
+    sut.didPush(overlayRoute, null);
+
+    expect(fake.screenName, null);
+  });
+
+  test('allows overriding the route filter', () {
+    final overlayRoute = CustomOverlawRoute(
+      settings: const RouteSettings(name: 'Overlay Route'),
+    );
+
+    bool defaultPostHogRouteFilter(Route<dynamic>? route) =>
+        route is PageRoute || route is OverlayRoute;
+
+    final sut = getSut(routeFilter: defaultPostHogRouteFilter);
+    sut.didPush(overlayRoute, null);
+
+    expect(fake.screenName, 'Overlay Route');
+  });
+}
+
+class CustomOverlawRoute extends OverlayRoute {
+  CustomOverlawRoute({super.settings});
+
+  @override
+  Iterable<OverlayEntry> createOverlayEntries() {
+    return [];
+  }
+}