Components solution does not build due to missing .npmproj

[rynowak]

This is failing after the recent changes to fix the build of our node-related projects.

VS doesn't appear to support adding projects with arbitrary .*proj file extensions (not an option in the UI, and the commandline dotnet sln add rejects it).

If I use my l33t hacker skills to edit the sln by hand then I get errors like:

36>C:\git\aspnet\AspNetCore\src\Components\test\testassets\BasicTestApp\BasicTestApp.csproj : error NU1105: Unable to find project information for 'C:\git\aspnet\AspNetCore\src\Components\Web.JS\Microsoft.AspNetCore.Components.Web.JS.npmproj'. Inside Visual Studio, this may be because the project is unloaded or not part of current solution so please run a restore from command-line. Otherwise the project file may be invalid or missing targets required for restore.
36>Done building project "BasicTestApp.csproj" -- FAILED.

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I think we either need to make these project conditional based on VS - or we need to change them to .msbuildproj - which is the file extension for general-purpose msbuild-based projects.

[dougbu]

Hmm, @Pilchie and @pranavkm our AspNetCore.sln file does not contain any *.npmproj projects nor any *.javaproj projects. In fact there are no matches for "src\\.*[^c][^s]proj" in the solution file at all. Won't that break people who just run .\restore.cmd from the command line and attempt to build many of our filtered solutions❔

[pranavkm]

I don't think sln files can include npmproj files. Projects that depend on the build output of npmproj files manually build them e.g. https://github.com/dotnet/aspnetcore/blob/master/src/Components/Server/src/Microsoft.AspNetCore.Components.Server.csproj#L31-L37

[dougbu]

@pranavkm should special cases like that work when building in VS❔ Or, are users required to build the *.npmproj projects before building in VS❔

[dougbu]

/ping @pranavkm

[pranavkm]

We require users to build the project from the command line before launching in VS. We've tried automating the npm reference and that does not work.

[dougbu]

@captainsafia this issue indicates a gap in the src/Components/README.md file. That file should indicate that executing src/Components/build.cmd before opening Visual Studio is strongly suggested because otherwise the NPM projects will not be up-to-date and the .NET SDK or runtimes may be missing.

[captainsafia]

@dougbu Done in #27833.