RunCommand prints "Building..." by default if it needs to build

[epidemicz]

When dotnet run needs to build the project it will now print the Building... message by default unless dotnetRunMessages is set to false.

• added test project that has dotnetRunMessages set to false
• added a test to ensure it is printed when dotnetRunMessage is true
• added a test to ensure it isn't printed when dotnetRunMessage is false
• changed test to ensure it is printed by default/no launch settings

I found it confusing that certain project templates would print the Building... message and others wouldn't.

It seems more consistent to have dotnet run print Building... by default. This also mirrors the behavior of dotnet watch

[epidemicz]

@dotnet-policy-service agree

[KalleOlaviNiemitalo]

Whether documentation would have to be updated if this PR were merged:

• I can't find any official documentation for dotnetRunMessages in Development and launchSettings.json, nor anywhere else in https://github.com/dotnet/AspNetCore.Docs/, https://github.com/dotnet/docs, or https://github.com/MicrosoftDocs/visualstudio-docs.
• dotnetRunMessages is documented in https://json.schemastore.org/launchsettings.json aka https://github.com/SchemaStore/schemastore/blob/f6487009667910b8f791c95ecfba3f7201255991/src/schemas/json/launchsettings.json#L201-L205, since Update launchsettings.json SchemaStore/schemastore#2507. However, this documentation is already wrong: it claims "type": "boolean" even though the values are strings in .NET SDK test cases at least.

The dotnetRunMessages setting was originally added in #12581 to fix #12227.

[KalleOlaviNiemitalo]

Outputting the "Building..." message by default could be a breaking change for users who use dotnet run on a console application, redirect the standard output, and expect it to contain only the output of the application itself. If a user hits that problem, I think they're likely to look in https://learn.microsoft.com/dotnet/core/tools/dotnet-run for a solution, so it could be useful to mention dotnetRunMessages there. On the other hand, perhaps those users should instead run dotnet build separately and then dotnet run --no-build; this avoids the "Building..." message as well as any MSBuild messages.

[baronfel]

Dotnet run should not show any build messages by default - specifically because users use this command as a shorthand for actually invoking their applications. This differs greatly from watch in intent.

[epidemicz]

You're right, I don't want to break anybody. Well a little, but it's probably not for the best. Thanks for the feedback, I think I will look into a PR to add some information about dotnetRunMessages, I think it could use it. Thanks again.