Prototype. Add references to SLN files without including them in your Aspire solution

_readme.md

NOTE: Aspire does not yet support loading projects by path alone. This is for if/when it does...

1: Add a reference to this library from your AspireHost app 2: Make sure the reference in your csproj is in the following format

3: Right-click your AppHost project and select "Add -> Existing item" 4: Browse to find the SLN file you want to use, then select it 5: Click the drop-down icon at the right side of the Add button, select "Add As Link" 6: Click the added SLN file in your solution explorer 7: View the properties for that file (F4) 8: Set the Build Action to "C# analyzer additional file"

If the name of your solution is MicroService1 and it contains projects Web.Api.csproj and MyFunctions.csproj then you can do this in your AppHost Program.cs file

builder.AddProject<Solution_MicroService1.Web_Api>("some-unique-name"); builder.AddProject<Solution_MicroService1.MyFunctions>("some-unique-name");

// If you have added multiple sln files then you can use those too builder.AddProject<Solution_MicroService2.SomeOtherApp>("some-unique-name");

Morris.Extensions.Aspire.ExternalSolutionSupport.csproj

<Project Sdk="Microsoft.NET.Sdk">
    <PropertyGroup>
        <Title>Morris.Extensions.Aspire.ExternalSolutionSupport</Title>
        <PackageId>Morris.Extensions.Aspire.ExternalSolutionSupport</PackageId>
        <Description>Referenced Solutions support for Aspire</Description>
        <Nullable>enable</Nullable>
        <ImplicitUsings>true</ImplicitUsings>
        <IncludeBuildOutput>false</IncludeBuildOutput>
        <IsRoslynComponent>true</IsRoslynComponent>
        <TargetFramework>netstandard2.0</TargetFramework>
        <EnforceExtendedAnalyzerRules>true</EnforceExtendedAnalyzerRules>
        <LangVersion>11</LangVersion>
    </PropertyGroup>

    <PropertyGroup>
        <NoWarn>NU5118;NU5128</NoWarn>
    </PropertyGroup>

    <ItemGroup>
        <Compile Remove="bin\**" />
        <EmbeddedResource Remove="bin\**" />
        <None Remove="bin\**" />
    </ItemGroup>

    <ItemGroup>
        <PackageReference Include="Microsoft.CodeAnalysis.Analyzers" Version="3.3.4" PrivateAssets="all" />
        <PackageReference Include="Microsoft.CodeAnalysis.CSharp" Version="4.4.0" PrivateAssets="all" />
    </ItemGroup>

    <ItemGroup>
        <None Remove="bin\Debug\netstandard2.0\\Morris.Extensions.Aspire.ExternalSolutionSupport.dll" />
    </ItemGroup>

    <ItemGroup>
        <None Include="$(OutputPath)\$(AssemblyName).dll" Pack="true" PackagePath="analyzers/dotnet/cs" Visible="false" />
    </ItemGroup>

    <ItemGroup>
        <!-- Generator package dependencies -->
        <PackageReference Include="Microsoft.CSharp" Version="4.7.0" PrivateAssets="all" GeneratePathProperty="true" />
    </ItemGroup>

    <PropertyGroup>
        <GetTargetPathDependsOn>$(GetTargetPathDependsOn);GetDependencyTargetPaths</GetTargetPathDependsOn>
    </PropertyGroup>

    <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
        <DebugType>portable</DebugType>
        <Optimize>False</Optimize>
    </PropertyGroup>

    <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">
        <DebugType>portable</DebugType>
        <Optimize>True</Optimize>
    </PropertyGroup>
    <Target Name="GetDependencyTargetPaths">
        <ItemGroup>
            <TargetPathWithTargetPlatformMoniker Include="$(PKGMicrosoft_CSharp)\lib\netstandard2.0\Microsoft.CSharp.dll" IncludeRuntimeDependency="false" />
        </ItemGroup>
    </Target>
</Project>

RoslynIncrementalGenerator.cs

using Microsoft.CodeAnalysis;
using System.Text;
using System.Text.RegularExpressions;

namespace Morris.Extensions.Aspire.ExternalSolutionSupport;

[Generator]
public partial class RoslynIncrementalGenerator : IIncrementalGenerator
{
	private static char Tab = '\t';
	private static string Tab2 = "\t\t";

	private static readonly Regex ProjectRegex = new Regex(
		@"^\s*Project\(s*""{\w{8}-\w{4}-\w{4}-\w{4}-\w{12}}""\s*\)\s*=\s*""(.*?)""\s*,\s*""(.*?)""\s*,\s*""{\w{8}-\w{4}-\w{4}-\w{4}-\w{12}}""",
		RegexOptions.Multiline | RegexOptions.Compiled);

	public void Initialize(IncrementalGeneratorInitializationContext context)
	{
		IncrementalValuesProvider<KeyValuePair<string, string>> solutionsToScan =
			context
				.AdditionalTextsProvider
				.Where(static x => x.Path.EndsWith(".sln", StringComparison.OrdinalIgnoreCase))
				.Select((file, cancellationToken) =>
					new KeyValuePair<string, string>(
						key: file.Path,
						value: file.GetText(cancellationToken)!.ToString()
					)
				);

		context.RegisterSourceOutput(
			source: solutionsToScan,
			static (productionContext, input) =>
			{
				MatchCollection matches = ProjectRegex.Matches(input.Value);
				if (matches.Count == 0)
					return;

				string slnFileDirectoryPath = Path.GetDirectoryName(input.Key);
				string slnClassName = Path
					.GetFileNameWithoutExtension(input.Key)
					.Replace('.', '_');

				var builder = new StringBuilder();
				builder.AppendLine("namespace Projects;");
				builder.AppendLine();
				builder.AppendLine($"public static class Solution_{slnClassName}");
				builder.AppendLine("{");

				foreach (Match match in matches)
				{
					string projectRelativePath = match.Groups[2].Value;
					if (projectRelativePath.EndsWith(".csproj", StringComparison.InvariantCultureIgnoreCase))
					{
						string projectFileName = match.Groups[1].Value;
						string projectClassName = Path
							.GetFileName(projectFileName)
							.Replace('.', '_');

						builder.AppendLine($$"""{{Tab}}[global::System.Diagnostics.DebuggerDisplay("Type = {GetType().Name,nq}, ProjectPath = {ProjectPath}")]""");
						builder.AppendLine($$"""{{Tab}}public class {{projectClassName}} : global::Aspire.Hosting.IProjectMetadata""");
						builder.AppendLine($$"""{{Tab}}{""");
						builder.AppendLine($$""""{{Tab2}}public string ProjectPath => """{{slnFileDirectoryPath}}\{{projectRelativePath}}""";"""");
						builder.AppendLine($$"""{{Tab}}}""");
						builder.AppendLine();
					}
				}

				builder.AppendLine("}");

				productionContext.AddSource($"{slnClassName}.g.cs", builder.ToString());
			}
		);
	}
}