feat: expose shrinkWrap of CustomScrollView

- Add shrinkWrap property to InfiniteList widget
- Update documentation to reference CustomScrollView.shrinkWrap
- Add tests to ensure property gets proxied and defaults to false
- Update README with shrinkWrap documentation

Addresses feedback from PR VeryGoodOpenSource#71

Author: ablause

README.md

@@ -132,6 +132,12 @@ InfiniteList<String>(
   // Is set to `false` by default.
   reverse: false,
 
+  // Indicates if the extent of the ScrollView in the scrollDirection
+  // should be determined by the contents being viewed.
+  //
+  // Is set to `false` by default.
+  shrinkWrap: false,
+
   // The duration with which calls to [onFetchData] will be debounced.
   //
   // Is set to a duration of 100 milliseconds by default.

lib/src/infinite_list.dart

@@ -32,6 +32,7 @@ class InfiniteList extends StatelessWidget {
     this.cacheExtent,
     this.debounceDuration = defaultDebounceDuration,
     this.reverse = false,
+    this.shrinkWrap = false,
     this.isLoading = false,
     this.hasError = false,
     this.hasReachedMax = false,
@@ -77,6 +78,14 @@ class InfiniteList extends StatelessWidget {
   /// {@endtemplate}
   final bool reverse;
 
+  /// Indicates if the extent of the [ScrollView] in the [scrollDirection]
+  /// should be determined by the contents being viewed.
+  ///
+  /// See also:
+  ///
+  /// * [CustomScrollView.shrinkWrap], for more details about this flag.
+  final bool shrinkWrap;
+
   /// {@template item_count}
   /// The amount of items that need to be rendered by the [itemBuilder].
   ///
@@ -207,6 +216,7 @@ class InfiniteList extends StatelessWidget {
     return CustomScrollView(
       scrollDirection: scrollDirection,
       reverse: reverse,
+      shrinkWrap: shrinkWrap,
       controller: scrollController,
       physics: physics,
       cacheExtent: cacheExtent,

test/infinite_list_test.dart

@@ -406,6 +406,36 @@ void main() {
             tester.widget<CustomScrollView>(find.byType(CustomScrollView));
         expect(customScrollView.reverse, reverse);
       });
+
+      testWidgets('shrinkWrap', (tester) async {
+        const shrinkWrap = true;
+        await tester.pumpApp(
+          InfiniteList(
+            itemCount: 10,
+            onFetchData: emptyCallback,
+            itemBuilder: (_, i) => Text('$i'),
+            shrinkWrap: shrinkWrap,
+          ),
+        );
+
+        final customScrollView =
+            tester.widget<CustomScrollView>(find.byType(CustomScrollView));
+        expect(customScrollView.shrinkWrap, shrinkWrap);
+      });
+
+      testWidgets('shrinkWrap defaults to false', (tester) async {
+        await tester.pumpApp(
+          InfiniteList(
+            itemCount: 10,
+            onFetchData: emptyCallback,
+            itemBuilder: (_, i) => Text('$i'),
+          ),
+        );
+
+        final customScrollView =
+            tester.widget<CustomScrollView>(find.byType(CustomScrollView));
+        expect(customScrollView.shrinkWrap, false);
+      });
     });
 
     group('centralized properties', () {