null safety migration

lib/paging.dart

@@ -24,9 +24,9 @@ class Pagination<T> extends StatefulWidget {
   ///
   /// The arguments [pageBuilder], [itemBuilder] must not be null.
   Pagination({
-    Key key,
-    @required this.pageBuilder,
-    @required this.itemBuilder,
+    Key? key,
+    required this.pageBuilder,
+    required this.itemBuilder,
     this.scrollDirection = Axis.vertical,
     this.progress,
     this.onError,
@@ -56,30 +56,30 @@ class Pagination<T> extends StatefulWidget {
   final Axis scrollDirection;
 
   /// When non-null [progress] widget is called to show loading progress
-  final Widget progress;
+  final Widget? progress;
 
   /// Handle error returned by the Future implemented in [pageBuilder]
-  final Function(dynamic error) onError;
+  final Function(dynamic error)? onError;
 
   final bool reverse;
-  final ScrollController controller;
-  final bool primary;
-  final ScrollPhysics physics;
+  final ScrollController? controller;
+  final bool? primary;
+  final ScrollPhysics? physics;
   final bool shrinkWrap = false;
-  final EdgeInsetsGeometry padding;
-  final double itemExtent;
+  final EdgeInsetsGeometry? padding;
+  final double? itemExtent;
   final bool addAutomaticKeepAlives = true;
   final bool addRepaintBoundaries = true;
   final bool addSemanticIndexes = true;
-  final double cacheExtent;
-  final int semanticChildCount;
+  final double? cacheExtent;
+  final int? semanticChildCount;
 
   @override
   _PaginationState<T> createState() => _PaginationState<T>();
 }
 
 class _PaginationState<T> extends State<Pagination<T>> {
-  final List<T> _list = List();
+  final List<T> _list = List.empty();
   bool _isLoading = false;
   bool _isEndOfList = false;
 
@@ -100,7 +100,7 @@ class _PaginationState<T> extends State<Pagination<T>> {
         });
         print(error);
         if (widget.onError != null) {
-          widget.onError(error);
+          widget.onError!(error);
         }
       });
     }
@@ -134,7 +134,7 @@ class _PaginationState<T> extends State<Pagination<T>> {
           fetchMore();
           return widget.progress ?? defaultLoading();
         }
-        return null;
+        return const SizedBox.shrink();
       },
     );
   }

pubspec.lock

@@ -1,34 +1,55 @@
 # Generated by pub
-# See https://www.dartlang.org/tools/pub/glossary#lockfile
+# See https://dart.dev/tools/pub/glossary#lockfile
 packages:
   async:
     dependency: transitive
     description:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.8"
+    version: "2.8.1"
   boolean_selector:
     dependency: transitive
     description:
       name: boolean_selector
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.4"
+    version: "2.1.0"
+  characters:
+    dependency: transitive
+    description:
+      name: characters
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.1.0"
   charcode:
     dependency: transitive
     description:
       name: charcode
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.2"
+    version: "1.3.1"
+  clock:
+    dependency: transitive
+    description:
+      name: clock
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.1.0"
   collection:
     dependency: transitive
     description:
       name: collection
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.14.11"
+    version: "1.15.0"
+  fake_async:
+    dependency: transitive
+    description:
+      name: fake_async
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "1.2.0"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -45,28 +66,21 @@ packages:
       name: matcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.3+1"
+    version: "0.12.10"
   meta:
     dependency: transitive
     description:
       name: meta
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.6"
+    version: "1.7.0"
   path:
     dependency: transitive
     description:
       name: path
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.6.2"
-  quiver:
-    dependency: transitive
-    description:
-      name: quiver
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.0.1"
+    version: "1.8.0"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -78,55 +92,55 @@ packages:
       name: source_span
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.4.1"
+    version: "1.8.1"
   stack_trace:
     dependency: transitive
     description:
       name: stack_trace
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.9.3"
+    version: "1.10.0"
   stream_channel:
     dependency: transitive
     description:
       name: stream_channel
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.6.8"
+    version: "2.1.0"
   string_scanner:
     dependency: transitive
     description:
       name: string_scanner
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.4"
+    version: "1.1.0"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.1"
+    version: "1.2.0"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.1"
+    version: "0.4.2"
   typed_data:
     dependency: transitive
     description:
       name: typed_data
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.6"
+    version: "1.3.0"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.8"
+    version: "2.1.0"
 sdks:
-  dart: ">=2.0.0 <3.0.0"
+  dart: ">=2.12.0 <3.0.0"

pubspec.yaml

@@ -5,7 +5,7 @@ author: Joshua Matta<[email protected]>
 homepage: https://github.com/joshmatta/paging_library
 
 environment:
-  sdk: ">=2.0.0-dev.68.0 <3.0.0"
+  sdk: '>=2.12.0 <3.0.0'
 
 dependencies:
   flutter: