determine whether reload-on-save should trigger for all files and file types

[lukef]

I'm sure there are valid reasons for this...
If you're editing your README.md, CHANGELOG, etc then hot reload will fire on each save. It might make sense to exclude certain top-level files or make it specific to .dart files?

[pq]

/cc @devoncarew

[devoncarew]

Hi @lukef!

We did get some feedback from UX on an earlier version of this feature, which did do something similar to what you suggested. It reloaded either on dart project files, or whether there was an actual change to a file. What we found was that it was difficult to reason for the user about when a save would reload, and the mental model they formed was more that cmd-S was the keybinding for reload.

This is currently working as intended, but we're definitely happy to get feedback about how well its working, or ideas for improvements.

[lukef]

Hey @devoncarew. What if there was an exclude option in the project settings? That way if you have assets, documentation, etc then they won't trigger reloads? By default, nothing could be excluded.

[devoncarew]

Hmm, currently we'd trigger even if there was no file open. If we didn't - or filtered on some specific project files or file types - then the user may not always understand why cmd-s reloads some of the times but not others. I.e. they'd need a more sophisticated mental modal than 'cmd-s == reload', it would need to be something like 'cmd-s == reload, if there's a file open, and the file is essentially an asset of your app'.

I'm curious what the issue is that you're running into? Unexpected or undesired reloads when editing project documentation?

cc'ing @InMatrix for thoughts about what would be successful here

[lukef]

I guess, to be totally fair, I could just stop the app while editing certain files. It just seems weird / bad / unpredictable to have the app hot reloading in the background when I'm editing a file that is not associated directly with the compilation process.

I'm curious what users would really be confused that hot reload wasn't working when hitting ctrl+s while editing a support / non-dart file. i.e.: README.md. I would think that it would be expected that editing README.md would not trigger a reload.

It's honestly not a big deal at the EOD, however, I would be annoyed if I went to edit the README and then find that the app has changed state, a test that i'm running has been affected, or something like that. To me that seems a poor experience.

[lukef]

VS code has an option like this for file watcher (not sure if the dart plugin observes it):

"files.watcherExclude": {
    "**/.git/objects/**": true,
    "**/.git/subtree-cache/**": true,
    "**/node_modules/*/**": true
}

I was wondering if it's possible to add something like that on a workspace/per project basis?

[DanTup]

FWIW, in VS Code we hook the save event for hot reload (which means if VS Code decides there's nothing to save, it won't trigger, even if you're hitting the Save shortcut key). Then we check:

• flutterHotReloadOnSave is enabled
• The file is in the an open workspace folder
• The file extension of the save is .dart
• There are no diagnostics of type Error in the problems list for that file

If we get past all that, we set a 200ms timer to reload (and reset that 200ms timer if additional events come through - this is basically to stop multiple hot-reloads if the user hits Save All with multiple dirty files).

It might make sense to align these, though I'm not sure if I could reliably catch the Save short-cut key in a way that would fire when there are no changes (we could bind to Cmd+S, but the user can re-bind this or save using the file menu, etc.).