flutter - 如何为 statefulwidget 创建小部件测试

Question

我有 3 个不同的文件/屏幕（主要、登录和注册），其中登录和注册是 statefulwidgtes。我想在屏幕上执行小部件测试，但是，似乎我无法在登录和注册下获取小部件，每次尝试我都会收到消息：

预期：小部件树中恰好有一个匹配节点实际：_WidgetTypeFinder：<零个类型为“ListView”的小部件（忽略后台小部件）>这意味着没有找到，但应该有一个

请注意，在上面的示例中，ListView 小部件确实存在，但没有被测试人员定位。

这是主要小部件的代码

import "package:flutter/material.dart";
import 'package:loginscreen/setup/login.dart';
import 'package:firebase_core/firebase_core.dart';
// void main() => runApp(MyApp());

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        theme: ThemeData(primarySwatch: Colors.blue), home: LoginPage());
  }
}

登录页面代码：

import 'package:flutter/material.dart';
import './signup.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:loginscreen/pages/home.dart';
import 'package:modal_progress_hud/modal_progress_hud.dart';

class LoginPage extends StatefulWidget {
  LoginPage({Key key}) : super(key: key);

  @override
  State<StatefulWidget> createState() => new _State();
}

class _State extends State<LoginPage> {
  TextEditingController nameController = TextEditingController();
  TextEditingController passwordController = TextEditingController();
  String email;
  String password;
  final _auth = FirebaseAuth.instance;
  bool showSpinner = false;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Sign In'),
      ),
      body: ModalProgressHUD(
        inAsyncCall: showSpinner,
        child: Padding(
          padding: EdgeInsets.all(10),
          child: ListView(
            children: <Widget>[
              Container(
                  alignment: Alignment.center,
                  padding: EdgeInsets.all(10),
                  child: Text(
                    'Firebase Authentication',
                    style: TextStyle(
                        color: Colors.blue,
                        fontWeight: FontWeight.w500,
                        fontSize: 30),
                  )),
              Container(
                padding: EdgeInsets.all(10),
                child: TextField(
                  keyboardType: TextInputType.emailAddress,
                  onChanged: (value) {
                    email = value;
                  },
                  controller: nameController,
                  decoration: InputDecoration(
                    border: OutlineInputBorder(),
                    labelText: 'Email Address',
                  ),
                ),
              ),
              Container(
                padding: EdgeInsets.fromLTRB(10, 10, 10, 0),
                child: TextField(
                  onChanged: (value) {
                    password = value;
                  },
                  obscureText: true,
                  controller: passwordController,
                  decoration: InputDecoration(
                    border: OutlineInputBorder(),
                    labelText: 'Password',
                  ),
                ),
              ),
              TextButton(
                onPressed: () {
                  //forgot password screen
                },
                // textColor: Colors.blue,
                child: Text('Forgot Password'),
              ),
              Container(
                height: 50,
                padding: EdgeInsets.fromLTRB(10, 0, 10, 0),
                // ignore: deprecated_member_use
                child: RaisedButton(
                  textColor: Colors.white,
                  color: Colors.blue,
                  child: Text('Login'),
                  onPressed: () async {
                    setState(() {
                      showSpinner = true;
                    });
                    try {
                      await _auth.signInWithEmailAndPassword(
                          email: email, password: password);
                      setState(() {
                        showSpinner = true;
                      });
                      Navigator.push(
                        context,
                        MaterialPageRoute(
                          builder: (context) => WelcomePage(),
                        ),
                      );
                    } on FirebaseAuthException catch (e) {
                      if (e.code == 'user-not-found') {
                        print('No user found for that email.');
                      } else if (e.code == 'wrong-password') {
                        print('Wrong password provided for that user.');
                      }
                    }
                  },
                ),
              ),
              Container(
                  child: Row(
                children: [
                  Text('Don\'t not have account?'),
                  // ignore: deprecated_member_use
                  FlatButton(
                    textColor: Colors.blue,
                    child: Text(
                      'Sign Up',
                      style: TextStyle(fontSize: 20),
                    ),
                    onPressed: () {
                      Navigator.push(
                        context,
                        MaterialPageRoute(builder: (context) => SignupPage()),
                      );
                    },
                  )
                ],
                mainAxisAlignment: MainAxisAlignment.center,
              ))
            ],
          ),
        ),
      ),
    );
  }
}

注册页面代码：

import 'package:flutter/material.dart';
import './login.dart';
import 'package:firebase_auth/firebase_auth.dart';
import 'package:loginscreen/pages/home.dart';
import 'package:modal_progress_hud/modal_progress_hud.dart';

class SignupPage extends StatefulWidget {
  @override
  State<StatefulWidget> createState() => new _State();
}

class _State extends State<SignupPage> {
  TextEditingController nameController = TextEditingController();
  TextEditingController passwordController = TextEditingController();
  final _auth = FirebaseAuth.instance;
  String email;
  String password;
  String repeatpassword;
  bool showSpinner = false;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: Text('Login Screen App'),
        ),
        body: ModalProgressHUD(
            inAsyncCall: showSpinner,
            child: Padding(
                padding: EdgeInsets.all(10),
                child: ListView(
                  children: <Widget>[
                    Container(
                        alignment: Alignment.center,
                        padding: EdgeInsets.all(10),
                        child: Text(
                          'Firebase Authentication',
                          style: TextStyle(
                              color: Colors.blue,
                              fontWeight: FontWeight.w500,
                              fontSize: 30),
                        )),
                    Container(
                      padding: EdgeInsets.all(10),
                      child: TextField(
                        keyboardType: TextInputType.emailAddress,
                        onChanged: (value) {
                          email = value;
                        },
                        controller: nameController,
                        decoration: InputDecoration(
                          border: OutlineInputBorder(),
                          labelText: 'Email Address',
                        ),
                      ),
                    ),
                    Container(
                      padding: EdgeInsets.fromLTRB(10, 10, 10, 0),
                      child: TextField(
                        onChanged: (value) {
                          password = value;
                        },
                        obscureText: true,
                        controller: passwordController,
                        decoration: InputDecoration(
                          border: OutlineInputBorder(),
                          labelText: 'Password (must be at least 6 characters)',
                        ),
                      ),
                    ),
                    Container(
                      padding: EdgeInsets.fromLTRB(10, 10, 10, 0),
                      child: TextField(
                        onChanged: (value) {
                          repeatpassword = value;
                        },
                        obscureText: true,
                        controller: passwordController,
                        decoration: InputDecoration(
                          border: OutlineInputBorder(),
                          labelText: 'Repeat Password',
                        ),
                      ),
                    ),
                    TextButton(
                      onPressed: () {
                        //forgot password screen
                      },
                      // textColor: Colors.blue,
                      child: Text('Forgot Password'),
                    ),
                    Container(
                      height: 50,
                      padding: EdgeInsets.fromLTRB(10, 0, 10, 0),
                      child: ElevatedButton(
                        // textColor: Colors.white,
                        // color: Colors.blue,
                        child: Text('Sign Up'),
                        onPressed: () async {
                          setState(() {
                            showSpinner = true;
                          });
                          try {
                            // UserCredential userCredential =
                            await _auth.createUserWithEmailAndPassword(
                                email: email, password: password);
                            setState(() {
                              showSpinner = false;
                            });
                            Navigator.push(
                              context,
                              MaterialPageRoute(
                                builder: (context) => WelcomePage(),
                              ),
                            );
                          } on FirebaseAuthException catch (e) {
                            if (e.code == 'weak-password') {
                              print('The password provided is too weak.');
                            } else if (e.code == 'email-already-in-use') {
                              print(
                                  'The account already exists for that email.');
                            }
                          } catch (e) {
                            print(e);
                          }
                        },
                      ),
                    ),
                    Container(
                        child: Row(
                      children: <Widget>[
                        Text('Already have an account?'),
                        // ignore: deprecated_member_use
                        FlatButton(
                          textColor: Colors.blue,
                          child: Text(
                            'Sign in',
                            style: TextStyle(fontSize: 20),
                          ),
                          onPressed: () {
                            Navigator.push(
                              context,
                              MaterialPageRoute(
                                  builder: (context) => LoginPage()),
                            );
                          },
                        )
                      ],
                      mainAxisAlignment: MainAxisAlignment.center,
                    ))
                  ],
                ))));
  }
}

登录页面小部件测试（这不起作用）：

import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:loginscreen/setup/login.dart';

void main() {
  testWidgets(' ', (WidgetTester tester) async {
    // add it to the widget tester
    await tester.pumpWidget(LoginPage());

    expect(find.byType(Text), findsOneWidget);
    
  });
}

所以我的问题是，如何测试登录和注册有状态小部件？如何在这些屏幕中获取小部件？流感