Hot reload warning when adding new members

[mit-mit]

1. Create a new app
2. Replace main.dart with:

import 'package:flutter/material.dart';

void main() => runApp(new MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      home: new Scaffold(
        appBar: new AppBar(
          title: new Text('Hot reload test'),
        ),
        body: new Center(child: new Text('Foo')),
      ),
    );
  }
}

3. Add a new member to MyApp:

class MyApp extends StatelessWidget {
  var foo = 'foo';
  @override
  ...
}

4. Hot reload
   => get a warning that the new member wasn't reloaded?

Some program elements were changed during reload but did not run when the view was reassembled;
you may need to restart the app for the changes to have an effect.
• MyApp.foo (lib/main.dart:6)
• MyApp.foo= (lib/main.dart:6)

[mit-mit]

cc @rmacnak-google

[rmacnak-google]

The message doesn't claim the addition of foo wasn't loaded. It says that foo was added but no subsequently read nor written (getter and setter did not run). This change introduces dead code.

[mit-mit]

The message says some elements were changed, and then lists foo, which was changed, it was added. The message may technically be correct, but from a user point of view, it's very confusing.

[mit-mit]

Also, the following interaction where the code isn't dead still leads to the warning:

Launch this program:

import 'package:flutter/material.dart';

void main() => runApp(new MaterialApp(home: new MyHomePage(title: 'Hot reload')));

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => new _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  var foo = 12;

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: new Text(widget.title),
      ),
      body: new Center(
        child: new Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            new Text('$foo'),
            new Text('hello'),
          ],
        ),
      ),
    );
  }
}

Next:

1. add var bar = 42; below var foo = 12;
2. change new Text('hello') to new Text('hello $bar')
3. reload

=>

Some program elements were changed during reload but did not run when the view was reassembled;
you may need to restart the app for the changes to have an effect.
• _MyHomePageState.bar= (lib/main.dart:16)

And while we are at it, next:

1. change var foo = 12; to var foo = 42;
2. reload

=> no warning that foo was reinitialized, but that program change wasn't reloaded

[Hixie]

• _MyHomePageState.bar= (lib/main.dart:16)

Well technically that one is true, the setter wasn't called. :-)

But yeah, that's not useful.

[zoechi]

Can't reproduce both examples.

The only output is

Initializing hot reload...
Syncing files to device Android SDK built for x86...
Reloaded 1 of 421 libraries in 1,173ms.

[github-actions]

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