Null Children Should be Allowed

[agrosner]

Steps to Reproduce

class AppBuildInfoItem extends StatelessWidget {
  final BuildInfo buildInfo;

  AppBuildInfoItem(this.buildInfo);

  @override
  Widget build(BuildContext context) {
    return new ListTile(
        title: Padding(
            padding: EdgeInsets.fromLTRB(0.0, 0.0, 0.0, 8.0),
            child: Text("Build ${buildInfo.displayName}")),
        subtitle: Text(buildInfo.getDisplayTime()),
        trailing: Row(children: <Widget>[
          buildInfo.result != "SUCCESS" ? Text(buildInfo.result) : null,
          Platform.isAndroid ? null : Icon(Icons.chevron_right),
        ]));
  }
}

flutter: Another exception was thrown: 'package:flutter/src/widgets/framework.dart': Failed assertion: line 1648 pos 14: '!children.any((Widget child) => child == null)': is not true.

We should be able to return null items in a Widget[] and the framework should just globally filter those out. This is useful coming from React, where this is completely valid.

Flutter Doctor

Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel dev, v0.3.3, on Mac OS X 10.13.4 17E199, locale en-US)
[✓] Android toolchain - develop for Android devices (Android SDK 27.0.3)
[✓] iOS toolchain - develop for iOS devices (Xcode 9.3)
[✓] Android Studio (version 3.0)
✗ Flutter plugin not installed; this adds Flutter specific functionality.
✗ Dart plugin not installed; this adds Dart specific functionality.
[✓] Android Studio (version 3.1)
✗ Flutter plugin not installed; this adds Flutter specific functionality.
✗ Dart plugin not installed; this adds Dart specific functionality.
[✓] IntelliJ IDEA Ultimate Edition (version 2018.1.1)
[✓] Connected devices (3 available)

• No issues found!

[StokeMasterJack]

Agreed. This makes a lot of coding scenarios easier. Which is why React works this way.

[lyquocnam]

hope this will done soon !

[zoechi]

Closing as dup of #17862.
This one is older but the other has more discussion and upvotes.

[github-actions]

This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of flutter doctor -v and a minimal reproduction of the issue.