Add a way to associate inputs and outputs in FastUpToDate

Visual Studio Version: 16.4 Preview 2.0

Summary:

Linked ASP.NET Core issue: https://github.com/aspnet/AspNetCore/issues/13204

ASP.NET Core projects produce two compiled outputs: .cs files (et al) produce an App.dll, .cshtml files produce an App.Views.dll. When a cshtml file changes, App.dll remains unchanged, but a newer App.Views.dll needs to be compiled.

To allow a build to occur when cshtml files change, ASP.NET Core projects (via the Microsoft.NET.Sdk.Razor SDK), add cshtml files to UpToCheckInput. Fast UpToDateCheck is now aware of these files and rebuild when these files change. However doing so also leaves FastUpToDateCheck in an incosistent state - the input .cshtml file is always newer than the output MyApp.dll and consequently fast up to date check is broken until a user touches a cs file.

Feature request: The feature request was to have a way to associate inputs and outputs in FUTD. By default, everything would be associated with the default UpToDateCheckBuilt. However, Inputs would have a way to state that they specifically affect certain outputs. When FUTD runs, it correlates these and uses this to perform the dirty check.

[drewnoakes]

@rainersigwald thanks for the fix. Thankfully the horror will be contained within a local test project.

@pranavkm once the PR is up you’ll be able to F5 this repo to get the change into the Exp hive for further testing.

I asked @panopticoncentral about the difference between UpToDateCheckOutput and UpToDateCheckBuilt and the conclusion was that it’s historical. As part of the PR I’m preparing I’ll update our docs to improve our guidance on these features. I’ll be sure to include that information too, and suspect we can effectively deprecate UpToDateCheckOutput.

[rainersigwald]

It’s getting lucky 😦 (microsoft/msbuild#2835 for context)

@drewnoakes use something like this instead:

<Target Name="U2D" BeforeTargets="Compile">
  <ItemGroup>
    <UpToDateCheckInput Condition=" '%(Extension)' == '.cshtml' " Set="Views" />
    <UpToDateCheckBuilt Condition="$([System.String]::Copy(%(Identity)).EndsWith('.Views.dll'))" Set="Views" />
  </ItemGroup>
</Target>

(I know the String.Copy thing there is a horror: microsoft/msbuild#1155)