Customizable dotnet watch behavior

[Juulsn]

Background and Motivation

The dotnet watch command is an essential tool, especially for people working with non VS IDEs.
However, currently there is no way to modify the command arguments, which do start the process with the dotnet watch command if the DOTNET_WATCH env var is set, but also includes the --no-hot-reload option.
(Added in #515)

Introducing an annotation-based configuration would streamline the process, allowing developers to specify the dotnet watch behavior, especially the hot-reload option.

Proposed API

+ public sealed class DotnetWatchAnnotation(bool enableHotReload) : IResourceAnnotation
+ {
+     public bool EnableHotReload { get; } = enableHotReload;
+ }

Usage Examples

appBuilder.AddProject<Projects.WebProject>("webfrontend")
            .WithAnnotation(new DotnetWatchAnnotation(enableHotReload: true));

Alternative Designs

The .WithArgs() method could be overloaded, to allow to override the default options.
Currently the arguments just get appended at the end of the command.

Risks

The API change would not introduce any breaking changes

[Juulsn]

See #4846

[Juulsn]

hey @mitchdenny any news on this?

[mitchdenny]

No news. Thanks for submitting the API design proposal. One of the factors impacting this is that we are starting to look at adding the ability to stop and restart resources within the app model (where applicable). I can imagine that this will have impacts on things like hot reload.

So, this will likely be in a holding pattern until we figure that out. It might render this unnecessary and its best not to have two ways of doing things if we can avoid it.

[davidfowl]

First class dotnet watch support is coming, track the issue dotnet/sdk#36971