How to test TextButton in flutter?

Question

I'mm testing a Textbutton in ListTile as trailing, but it throws an exception.

The finder "zero widgets with icon "IconData(U+0E1B9)" (ignoring offstage widgets)" (used in a call to "tap()") could not find any matching widgets.

This is my test:

 var findIcon=find.byIcon(Icons.delete);
   await tester.tap(findIcon);
   await tester.pump();

And this is the UI:

return ListView.separated(
                  itemCount: value.newusers.length,
                  itemBuilder: (context, index) {
                    return Container(
                      height:80,
                      decoration: BoxDecoration(
                          color: Colors.indigo,
                        borderRadius:BorderRadius.all(Radius.circular(20))
                      ),
                      child: Padding(
                        padding: EdgeInsets.all(10),
                        child: ListTile(
                          textColor: Colors.white,
                          title: Text(value.newusers[index].descriptioin!),
                         trailing:TextButton(
                             // key: Key('delete'),
                             onPressed: () {
                           setState(() {
                             value.removeData(index);
                           });
                         },
                         child: Icon(Icons.delete)),
                          leading: Text(value.newusers[index].title!),
                        ),

I've also tried using descendant but it also throws the same an exception.

Here is the code with descendant:

   final addButton=find.byType(ListTile);
   final findButton=find.descendant(of: addButton,
       matching:find.byType(TextButton));

   await tester.tap(findButton);
   await tester.pumpAndSettle();

   for(int index=0;index<provider.newusers.length;index++){
     expect(provider.removeData(index),findsNothing);
   }