Support file-based apps with `dotnet watch`

[DamianEdwards]

We should consider updating dotnet watch to support file-based apps so that one can do dotnet watch app.cs.

[willdean]

Knowing that I am the old man shouting at clouds, can still I express a contrary opinion here? From the outside, dotnet watch as a product looks woefully under-resourced, seems terribly prone to breakage when asked to support new stuff and has performance and quality problems which appear intractable, despite heroic efforts by a very small number of individuals.

Breaking it to add Aspire support was kind-of understandable, because Aspire and dotnet watch have a similar sort of audience of people with complicated long-running applications.

Breaking it again to support single-file scripts would just be an insult to those of us whose apps take years to write and ages to restart.

[jjonescz]

Breaking it again to support single-file scripts

I don't think adding support for file-based apps could break dotnet watch support for existing scenarios, if that's what you mean. Especially considering that file-based apps use "normal" project files behind the scenes which dotnet watch already supports.

[DamianEdwards]

@willdean it was indeed unfortunate that dotnet watch scenarios have regressed a number of times over recently releases as the feature underwent some major refactorings and in some cases rewrites. The team is aware of this and is working to improve the regression testing coverage so that major breaks are less likely to happen in the future. In this case, as @jjonescz says, adding support for file-based apps is likely only a minor update with very low chance of causing issues in other scenarios.

[willdean]

Thanks @DamianEdwards - I guess my concern is that there could be a perception at MS that watch took a dip around NET9 release but that's all resolved, and so there's now spare resource to work on adding new features to it.

I don't think that this lot really supports that position.

Anyway, I have high hopes for the benefits of the better testing.