[Bug report] BuildContext isn't returnable from a 'Widget?' function in itemBuilder

[renanyoy]

Version

1.26.3

Platforms

macOS

Device Model

android

flutter info

blah..

How to reproduce?

The returned type 'BuildContext' isn't returnable from a 'Widget?' function, as required by the closure's context.dartreturn_of_invalid_type_from_closure

              SliverList.builder(
                itemCount: epub!.spine.length,
                itemBuilder: (context, i) =>
                    _sliverListContext = context; // <= error here, can't assign class var with context
                    BookChapter(epub: epub!, chapter: epub!.spine[i]),
              ),

Logs

Example code (optional)

Contact

No response

[LinXunFeng]

SliverList.builder(
  itemCount: epub!.spine.length,
-   itemBuilder: (context, i) =>
-       _sliverListContext = context; // <= error here, can't assign class var with context
-       BookChapter(epub: epub!, chapter: epub!.spine[i]),
+   itemBuilder: (context, i) {
+     _sliverListContext = context; 
+     return BookChapter(epub: epub!, chapter: epub!.spine[i]);
  },
),

This is a Dart syntax issue rather than a bug in the package