Support JavaScript Project System (esproj files)

[hicksjacobp]

Describe the Enhancement

This build pack currently only supports discovering csproj, fsproj, and vbproj files (see source). Additionally, this build pack only detects the need for node/npm when it sees either referenced in a Target/Exec/Command XML element hierarchy (see source).

Microsoft / Visual Studio also has esproj files, which are used for JavaScript projects. esproj files also don't use a Target/Exec/Command structure because it's hidden behind the Microsoft.VisualStudio.JavaScript.Sdk SDK, and instead an esproj file looks like:

<Project Sdk="Microsoft.VisualStudio.JavaScript.Sdk/0.5.128-alpha">
  <PropertyGroup>
    <StartupCommand>npm run dev</StartupCommand>
    <JavaScriptTestRoot>src\</JavaScriptTestRoot>
    <JavaScriptTestFramework>Jest</JavaScriptTestFramework>
    <!-- Allows the build (or compile) script located on package.json to run on Build -->
    <ShouldRunBuildScript>false</ShouldRunBuildScript>
    <!-- Folder where production build objects will be placed -->
    <PublishAssetsDirectory>$(MSBuildProjectDirectory)\dist</PublishAssetsDirectory>
  </PropertyGroup>
</Project>

For reference of esproj files, please see:

• Property pages for React, Angular, and Vue projects in Visual Studio
• JavaScript and TypeScript in Visual Studio | Project templates
• MSBuild reference for the JavaScript Project System
• Tutorial: Create an ASP.NET Core app with React in Visual Studio

Possible Solutions

One, or a combination, of the following:

1. Look for esproj files in FindProjectFile

   A file extension by itself is not truly indicative of a dependency on node/npm, but fairly likely.

2. Look for usage of the Microsoft.VisualStudio.JavaScript.Sdk SDK in any project file?

   Usage of the SDK would be a better indicator of needing the node/npm commands.

3. Look for package.json files, similar to how the npm-install build pack detects its need (see source)?

   This may be a bit of a stretch for this build pack without a direct linkage to some .NET project / solution.

Motivation

With lack of support for esproj files, it requires developers to add unnecessary customizations to other project files in order for node/npm to be detected as being necessary and available during a build, similar to a MSBuild Target like what's in the Angular MSBuild .csproj file:

dotnet-publish/integration/testdata/angular_msbuild/angular_msbuild.csproj

Lines 24 to 32 in 982a8ad

	<Target Name="DebugEnsureNodeEnv" BeforeTargets="Build" Condition=" '$(Configuration)' == 'Debug' And !Exists('$(SpaRoot)node_modules') ">
	<!-- Ensure Node.js is installed -->
	<Exec Command="node --version" ContinueOnError="true">
	<Output TaskParameter="ExitCode" PropertyName="ErrorCode" />
	</Exec>
	<Error Condition="'$(ErrorCode)' != '0'" Text="Node.js is required to build and run this project. To continue, please install Node.js from https://nodejs.org/, and then restart your command prompt or IDE." />
	<Message Importance="high" Text="Restoring dependencies using 'npm'. This may take several minutes..." />
	<Exec WorkingDirectory="$(SpaRoot)" Command="npm install" />
	</Target>

. In the case of the ASP.NET React template, this would mean adding customizations to the server csproj file, in order for the client esproj to be built feasibly.