Test try-catch on cachemanager.

main.dart

import 'dart:io';
import 'package:flutter/material.dart';
import 'package:flutter_cache_manager/flutter_cache_manager.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Demo',
      home: Scaffold(
        appBar: AppBar(title: Text('demo')),
        body: TestWidget(),
      ),
    );
  }
}

class TestWidget extends StatefulWidget {
  @override
  _TestWidgetState createState() => _TestWidgetState();
}

class _TestWidgetState extends State<TestWidget> {
  String imageName = "loading...";

  @override
  void initState() {
    getFile().then((file) {
      setState(() {
        if(file == null){
          imageName = 'loading failed';
        }else{
          imageName = file.path.split('/').last;
        }
      });
    });
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Center(
      child: Text(imageName),
    );
  }

  Future<File> getFile() async {
    var url = 'https://notworkingtesturl.com/not-an-image';
    try {
      var file = await DefaultCacheManager().getSingleFile(url);
      return file;
    } catch (e) {
      print(e);
      return null;
    }
  }
}