Breakpoint is ignored after code is edited (no reload).

[turnidge]

Steps to reproduce:

1. Create a new flutter application with the demo app.
2. Set a breakpoint on the line with "_counter++;"

3. Debug "main.dart.
4. Add 6 lines of comments above the breakpoint. Do not save or reload.

5. Click the (+) button in the demo app.

EXPECTED: Program stops at breakpoint in the original, unedited source code. This source code is known to the vm and is available through the vm service.
ACTUAL: Breakpoint is apparently ignored.

cc'ing @johnmccutchan

[johnmccutchan]

cc @mit-mit

[mit-mit]

@pq is this the same as #305 even though there is no reload in this case?

[johnmccutchan]

@mit-mit This is a different issue. It appears that as the programmer modifies their source code the plugin is telling the VM to move breakpoints. This confuses the VM because it is running the unmodified source code. The plugin must always update source code + breakpoints atomically.

[mit-mit]

It appears that as the programmer modifies their source code the plugin is telling the VM to move breakpoints. This confuses the VM because it is running the unmodified source code. The plugin must always update source code + breakpoints atomically.

I agree this is unexpected. The plugin should not push breakpoint updates until the developer pushes code changes to target (i.e., when the developer hits reload or restart) -- I believe this is #305.

EXPECTED: Program stops at breakpoint in the original, unedited source code. This source code is known to the vm and is available through the vm service.

I am not convinced this is expected. I think it would be perfectly find to have the program stop at counter++ still showing the comment lines that were added above.

[pq]

@skybrian : while you're looking at debugging in general, could you take a poke at this updating the status of this one?

[skybrian]

This is looking tricky. IDEA doesn't do this for other languages and the debugger code isn't entirely under our control - it's split between the Flutter plugin, Dart plugin, and the IDEA framework. So we're probably going to put this off.

Instead, I think we should show some kind of warning when the code is out of date, maybe with a button for the user to hot reload. (Not sure about the UI, though.)

[johnmccutchan]

@skybrian Can you please document your findings and recommendation and then we can discuss it at tomorrow's devtools meeting?

[skybrian]

Sure. I don't see this meeting on my calendar. Could you send me an invite?

[johnmccutchan]

@skybrian You've been invited.

[skybrian]

I don't believe anything has changed. As I'll be on leave, unassigning for triage.

[stevemessick]

Closing this since it now works as it should: stops at the breakpoint in the edited code.