DartPad autorun generates an incorrect UI on 'Building user interfaces with Flutter' page

[syedaniq]

Page URL

https://docs.flutter.dev/ui/

Page source

https://github.com/flutter/website/tree/main/src/content/ui/index.md

Describe the problem

When visiting this page, the code runner output window displays a "hello $i" loop printing 10 times, even though the code on the left side is a centered text widget. However, when the "Run" button is pressed, the correct output is displayed.

Expected fix

Output window should be empty like the other ones below.

Additional context

I'm on macOS 14.5, this behavior occured in Firefox and Microsoft Edge.

I would like to fix this problem.

• I will try and fix this problem on docs.flutter.dev.

[johnpryan]

This is an issue with the auto-run feature (dart-lang/dart-pad#2985). It works if you press "Run" again.

[sfshaza2]

For me, there IS no run button. @RedBrogdon says: "That's fascinating. It only affects the frame that's onscreen when loaded. There must be some kind of race going on with firing off the compilation request and injecting the code into the editor."

@parlough, can you look into this?

[johnpryan]

For me, there IS no run button.

That's... concerning. Could you post a screenshot?

[sfshaza2]

@johnpryan, I thought I posted a screenshot. But here it is:

[johnpryan]

Ah, thanks. The Run button will only show when you select the "Code" tab. Filed an issue to track: dart-lang/dart-pad#2998