Add nuvigator maybeOf (#117)

* Add Nuvigator.maybeOf

* Change initialArguments type

* Fix example

* Add 2.0.0-beta.5 changelog

Author: raapperez

CHANGELOG.md

@@ -1,5 +1,10 @@
 # CHANGELOG
 
+## 2.0.0-beta.5
+- [BREAKING] Update dart SDK to `>=2.17 < 4.0.0`
+- [BREAKING] Split the `Nuvigator.of` nullOk's logic in two methods: `Nuvigator.of` and `Nuvigator.maybeOf`
+- [BREAKING] Change Nuvigator's `initialArguments` type to `Map<String, dynamic>?`
+
 ## 2.0.0-beta.4
 - [FIX] Fix nullability check when there are no path parameters to be extracted
 

example/lib/samples/screens/home_screen.dart

@@ -36,7 +36,7 @@ class HomeScreen extends StatelessWidget {
                   onPressed: () {
                     // final r = NuRouter.of<OldFriendRequestRouter>(context);
                     // r.toListRequests();
-                    nuvigator?.open<void>(
+                    nuvigator.open<void>(
                       'exapp://friend-requests?numberOfRequests=10',
                     );
                   },
@@ -46,7 +46,7 @@ class HomeScreen extends StatelessWidget {
                   onPressed: () async {
                     String? text;
 
-                    text = await nuvigator?.open<String>(
+                    text = await nuvigator.open<String>(
                       'exapp://composer/text?initialText=Hello+deep+link%21',
                       screenType: cupertinoDialogScreenType,
                     );

lib/src/nuvigator.dart

@@ -79,7 +79,7 @@ class _NuvigatorInner<T extends INuRouter> extends Navigator {
   _NuvigatorInner({
     required this.router,
     required String initialDeepLink,
-    Map<String, Object>? initialArguments,
+    Map<String, dynamic>? initialArguments,
     Key? key,
     List<NavigatorObserver> observers = const [],
     this.screenType = materialScreenType,
@@ -133,7 +133,7 @@ class _NuvigatorInner<T extends INuRouter> extends Navigator {
 class NuvigatorState<T extends INuRouter> extends NavigatorState
     with WidgetsBindingObserver {
   NuvigatorState get rootNuvigator =>
-      Nuvigator.of(context, rootNuvigator: true) ?? this;
+      Nuvigator.maybeOf(context, rootNuvigator: true) ?? this;
 
   List<NuvigatorState> nestedNuvigators = [];
 
@@ -174,7 +174,7 @@ class NuvigatorState<T extends INuRouter> extends NavigatorState
 
   @override
   void initState() {
-    parent = Nuvigator.of(context, nullOk: true);
+    parent = Nuvigator.maybeOf(context);
     if (isNested) {
       parent!.nestedNuvigators.add(this);
     }
@@ -549,35 +549,49 @@ class Nuvigator<T extends INuRouter?> extends StatelessWidget {
   final List<ObserverBuilder> inheritableObservers;
   final List<NavigatorObserver> observers;
   final Key? _innerKey;
-  final Map<String, Object>? initialArguments;
+  final Map<String, dynamic>? initialArguments;
   final ShouldRebuildFn? shouldRebuild;
 
-  /// Fetches a [NuvigatorState] from the current BuildContext.
-  static NuvigatorState<T>? of<T extends INuRouter>(
+  /// Maybe fetches a [NuvigatorState] from the current BuildContext.
+  static NuvigatorState<T>? maybeOf<T extends INuRouter>(
     BuildContext context, {
     bool rootNuvigator = false,
-    bool nullOk = false,
   }) {
     if (rootNuvigator) {
       return context.findRootAncestorStateOfType<NuvigatorState<T>>();
     } else {
       final closestNuvigator =
           context.findAncestorStateOfType<NuvigatorState<T>>();
       if (closestNuvigator != null) return closestNuvigator;
-      assert(() {
-        if (!nullOk) {
-          throw FlutterError(
-              'Nuvigator operation requested with a context that does not include a Nuvigator.\n'
-              'The context used to push or pop routes from the Nuvigator must be that of a '
-              'widget that is a descendant of a Nuvigator widget.'
-              'Also check if the provided Router [T] type exists withing a the Nuvigator context.');
-        }
-        return true;
-      }());
+
       return null;
     }
   }
 
+  /// Fetches a [NuvigatorState] from the current BuildContext, or throws an
+  /// error if doesn't find it
+  static NuvigatorState<T> of<T extends INuRouter>(
+    BuildContext context, {
+    bool rootNuvigator = false,
+  }) {
+    final nuvigatorState =
+        Nuvigator.maybeOf<T>(context, rootNuvigator: rootNuvigator);
+
+    assert(() {
+      if (nuvigatorState == null) {
+        throw FlutterError(
+            'Nuvigator operation requested with a context that does not include a Nuvigator.\n'
+            'The context used to push or pop routes from the Nuvigator must be that of a '
+            'widget that is a descendant of a Nuvigator widget.'
+            'Also check if the provided Router [T] type exists withing a the Nuvigator context.');
+      }
+
+      return true;
+    }());
+
+    return nuvigatorState!;
+  }
+
   /// Helper method that allows passing a Nuvigator to a builder function
   Nuvigator call(BuildContext context, [Widget? child]) {
     return this;