Example showing that Future.ignore() doesn't work as expected

future_ignore_wtf.dart

import 'dart:async';
import 'dart:developer';

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';

void main() {
  FlutterError.onError = (details) {
    log('FlutterError error: ${details.exception}');
    FlutterError.presentError(details);
  };
  PlatformDispatcher.instance.onError = (error, stack) {
    log('PlatformDispatcher error: $error');
    return true;
  };
  runApp(const MainApp());
}

Future<void> someFuture() => throw UnimplementedError();

class ButtonThatThrows extends StatelessWidget {
  const ButtonThatThrows({super.key});
  @override
  Widget build(BuildContext context) => ElevatedButton(
      onPressed: () async {
        log('before');
        someFuture().ignore();
        log('after');
      },
      child: const Text('Throw'));
}

class MainApp extends StatelessWidget {
  const MainApp({super.key});

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      home: Scaffold(
        body: Center(
          child: ButtonThatThrows(),
        ),
      ),
    );
  }
}