Multi-target project support

CHANGELOG.md

@@ -11,6 +11,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
   - By @CoolCoderSuper https://github.com/razzmatazz/csharp-language-server/pull/226
 * Fix how doc strings are rendered
   - https://github.com/razzmatazz/csharp-language-server/pull/228
+* Implement (experimental) support for loading multi-tfm solutions
+  - https://github.com/razzmatazz/csharp-language-server/pull/205
 
 ## [0.17.0] - 2025-04-30 / Krokšlys
 * Upgrade Roslyn to 4.13.0

src/CSharpLanguageServer/Lsp/Server.fs

@@ -310,7 +310,8 @@ module Server =
         let serverCreator client =
             new CSharpLspServer(client, settings) :> ICSharpLspServer
 
-        let clientCreator = CSharpLspClient
+        let clientCreator =
+            fun (a, b) -> new CSharpLspClient(a, b)
 
         Ionide.LanguageServerProtocol.Server.start
             requestHandlings

src/CSharpLanguageServer/RoslynHelpers.fs

@@ -375,6 +375,73 @@ type CSharpLspHostServices () =
         let interceptor = WorkspaceServicesInterceptor()
         generator.CreateClassProxyWithTarget(services, interceptor)
 
+
+let loadProjectFilenamesFromSolution solutionPath =
+    let projectFilenames = new List<string>()
+
+    let solutionFile = Microsoft.Build.Construction.SolutionFile.Parse(solutionPath)
+    for project in solutionFile.ProjectsInOrder do
+        if project.ProjectType = Microsoft.Build.Construction.SolutionProjectType.KnownToBeMSBuildFormat then
+            projectFilenames.Add(project.AbsolutePath)
+
+    projectFilenames |> Set.ofSeq
+
+
+let resolveTargetFrameworkWorkspaceProps (logger: ILog) (projs: string seq) props =
+    let tfms = new List<string>()
+
+    for projectFilename in projs do
+        let projectCollection = new Microsoft.Build.Evaluation.ProjectCollection();
+        let props = new Dictionary<string, string>();
+
+        let buildProject = projectCollection.LoadProject(projectFilename, props, toolsVersion=null)
+
+        let noneIfEmpty s =
+            s |> Option.ofObj
+                |> Option.bind (fun s -> if String.IsNullOrEmpty(s) then None else Some s)
+
+        let targetFramework = buildProject.GetPropertyValue("TargetFramework") |> noneIfEmpty
+
+        match targetFramework with
+        | Some tfm ->
+            tfms.Add(tfm.Trim())
+        | _ -> ()
+
+        let targetFrameworks = buildProject.GetPropertyValue("TargetFrameworks") |> noneIfEmpty
+
+        match targetFrameworks with
+        | Some semicolonSeparatedTfms ->
+            for tfm in semicolonSeparatedTfms.Split(";") do
+                tfms.Add(tfm.Trim())
+        | _ -> ()
+
+        projectCollection.UnloadProject(buildProject)
+
+    let distinctTfms = tfms |> Set.ofSeq
+
+    logger.debug (
+        Log.setMessage "resolveDefaultWorkspaceProps: distinctTfms={distinctTfms}"
+        >> Log.addContext "distinctTfms" (string distinctTfms)
+    )
+
+    if distinctTfms.Count > 1 then
+        // select the highest tfm
+        let selectedTargetFramework =
+            distinctTfms
+            |> Seq.sortByDescending (fun s -> s)
+            |> Seq.head
+
+        props
+        |> Map.add "TargetFramework" selectedTargetFramework
+    else
+        props
+
+
+let resolveDefaultWorkspaceProps (logger: ILog) projs =
+    Map.empty
+    |> resolveTargetFrameworkWorkspaceProps logger projs
+
+
 let tryLoadSolutionOnPath
         (lspClient: ILspClient)
         (logger: ILog)
@@ -399,7 +466,16 @@ let tryLoadSolutionOnPath
             do! progress.Begin(beginMessage)
             do! logMessage beginMessage
 
-            let msbuildWorkspace = MSBuildWorkspace.Create(CSharpLspHostServices())
+            let projs = loadProjectFilenamesFromSolution solutionPath
+            let workspaceProps = resolveDefaultWorkspaceProps logger projs
+
+            if workspaceProps.Count > 0 then
+                logger.info (
+                    Log.setMessage "Will use these MSBuild props: {workspaceProps}"
+                    >> Log.addContext "workspaceProps" (string workspaceProps)
+                )
+
+            let msbuildWorkspace = MSBuildWorkspace.Create(workspaceProps, CSharpLspHostServices())
             msbuildWorkspace.LoadMetadataForReferencedProjects <- true
 
             let! solution = msbuildWorkspace.OpenSolutionAsync(solutionPath) |> Async.AwaitTask
@@ -436,8 +512,17 @@ let tryLoadSolutionFromProjectFiles
         do! progress.Begin($"Loading {projs.Length} project(s)...", false, $"0/{projs.Length}", 0u)
         let loadedProj = ref 0
 
-        let msbuildWorkspace = MSBuildWorkspace.Create(CSharpLspHostServices())
+        let workspaceProps = resolveDefaultWorkspaceProps logger projs
+
+        if workspaceProps.Count > 0 then
+            logger.info (
+                Log.setMessage "Will use these MSBuild props: {workspaceProps}"
+                >> Log.addContext "workspaceProps" (string workspaceProps)
+            )
+
+        let msbuildWorkspace = MSBuildWorkspace.Create(workspaceProps, CSharpLspHostServices())
         msbuildWorkspace.LoadMetadataForReferencedProjects <- true
+
         for file in projs do
             if projs.Length < 10 then
               do! logMessage (sprintf "loading project \"%s\".." file)

tests/CSharpLanguageServer.Tests/CSharpLanguageServer.Tests.fsproj

@@ -4,6 +4,7 @@
 
     <IsPackable>false</IsPackable>
     <GenerateProgramFile>false</GenerateProgramFile>
+    <NoWarn>FS0988</NoWarn>
   </PropertyGroup>
 
   <ItemGroup>

tests/CSharpLanguageServer.Tests/InitializationTests.fs

@@ -5,6 +5,25 @@ open NUnit.Framework
 open CSharpLanguageServer.Tests.Tooling
 open Ionide.LanguageServerProtocol.Types
 
+let assertHoverWorks (client: ClientController) file pos expectedMarkupContent =
+    use classFile = client.Open(file)
+
+    let hover0Params: HoverParams =
+        { TextDocument = { Uri = classFile.Uri }
+          Position = pos
+          WorkDoneToken = None
+        }
+
+    let hover0: Hover option = client.Request("textDocument/hover", hover0Params)
+
+    match hover0 with
+    | Some { Contents = U3.C1 markupContent; Range = None } ->
+        Assert.AreEqual(MarkupKind.Markdown, markupContent.Kind)
+        Assert.AreEqual(expectedMarkupContent, markupContent.Value)
+
+    | x -> failwithf "'{ Contents = U3.C1 markupContent; Range = None }' was expected but '%s' received" (string x)
+
+
 [<TestCase>]
 let testServerRegistersCapabilitiesWithTheClient () =
     use client = setupServerClient defaultClientProfile
@@ -120,11 +139,28 @@ let testServerRegistersCapabilitiesWithTheClient () =
 
 [<TestCase>]
 let testSlnxSolutionFileWillBeFoundAndLoaded () =
-    use client = setupServerClient defaultClientProfile
-                                   "TestData/testSlnx"
+    use client = setupServerClient defaultClientProfile "TestData/testSlnx"
     client.StartAndWaitForSolutionLoad()
 
     Assert.IsTrue(client.ServerMessageLogContains(fun m -> m.Contains "1 solution(s) found"))
 
     Assert.IsTrue(client.ServerDidRespondTo "initialize")
     Assert.IsTrue(client.ServerDidRespondTo "initialized")
+
+    assertHoverWorks
+        client
+        "Project/Class.cs" { Line = 2u; Character = 16u }
+        "```csharp\nvoid Class.MethodA(string arg)\n```"
+
+
+[<TestCase>]
+let testMultiTargetProjectLoads () =
+    use client = setupServerClient defaultClientProfile "TestData/testMultiTargetProjectLoads"
+    client.StartAndWaitForSolutionLoad()
+
+    Assert.IsTrue(client.ServerMessageLogContains(fun m -> m.Contains "loading project"))
+
+    assertHoverWorks
+        client
+        "Project/Class.cs" { Line = 2u; Character = 16u }
+        "```csharp\nvoid Class.Method(string arg)\n```"

tests/CSharpLanguageServer.Tests/TestData/testMultiTargetProjectLoads/Project/Class.cs

@@ -0,0 +1,6 @@
+class Class
+{
+    public void Method(string arg)
+    {
+    }
+}

tests/CSharpLanguageServer.Tests/TestData/testMultiTargetProjectLoads/Project/Project.csproj

@@ -0,0 +1,6 @@
+<Project Sdk="Microsoft.NET.Sdk">
+    <PropertyGroup>
+        <OutputType>Exe</OutputType>
+        <TargetFrameworks>net6.0;net8.0</TargetFrameworks>
+    </PropertyGroup>
+</Project>