[WIP] Lazy load projects

release/package.json

@@ -919,6 +919,11 @@
           "description": "Path to the directory or solution file that should be loaded as a workspace. If set, no workspace probing or discovery is done by Ionide at all.",
           "scope": "window",
           "type": "string"
+        },
+        "FSharp.lazyLoadWorkspace": {
+          "default": false,
+          "description": "Configures Ionide to not load any projects upfront but instead load them when .fs files are opened.",
+          "type": "boolean"
         }
       },
       "title": "F#",
@@ -1776,4 +1781,4 @@
     "url": "https://github.com/ionide/ionide-vscode-fsharp.git"
   },
   "version": "7.15.2"
-}
+}

src/Components/MSBuild.fs

@@ -469,7 +469,7 @@ module MSBuild =
         let unlessIgnored (path: string) f =
             if Project.isIgnored path then unbox () else f path
 
-        let initWorkspace _n = Project.initWorkspace ()
+        let initWorkspace _n = Project.initWorkspace context
 
         let solutionWatcher = workspace.createFileSystemWatcher (U2.Case1 "**/*.sln")
 

src/Components/SolutionExplorer.fs

@@ -257,7 +257,7 @@ module SolutionExplorer =
             setParentRef s result
             result
         | WorkspacePeekFound.Directory dir ->
-            let items = dir.Fsprojs |> Array.map getProjItem |> List.ofArray
+            let items = dir.Fsprojs |> Array.map (fun f -> getProjItem f.Path) |> List.ofArray
 
             let result = Workspace items
             setParentRefs items result
@@ -714,7 +714,7 @@ module SolutionExplorer =
         | PackageReference _
         | ProjectReference _ -> None
 
-    let newProject () =
+    let newProject (context: ExtensionContext) =
         promise {
             let! templates = LanguageService.dotnetNewList ()
 
@@ -777,7 +777,7 @@ module SolutionExplorer =
                             | _ ->
                                 //If it's the first project in the workspace we need to init the workspace
                                 if Project.getInWorkspace().IsEmpty then
-                                    do! Project.initWorkspace ()
+                                    do! Project.initWorkspace context
 
                         ()
                     | _ -> ()

src/Core/DTO.fs

@@ -271,12 +271,16 @@ module DTO =
 
     type WorkspacePeek = { Found: WorkspacePeekFound[] }
 
+    and WorkspacePeekFsproj =
+        { Path: string; CompileItems: string[] }
+
     and WorkspacePeekFound =
         | Directory of WorkspacePeekFoundDirectory
         | Solution of WorkspacePeekFoundSolution
 
     and WorkspacePeekFoundDirectory =
-        { Directory: string; Fsprojs: string[] }
+        { Directory: string
+          Fsprojs: WorkspacePeekFsproj[] }
 
     and WorkspacePeekFoundSolution =
         { Path: string

src/Core/Project.fs

@@ -58,6 +58,8 @@ module Project =
 
     let deepLevel = "FSharp.workspaceModePeekDeepLevel" |> Configuration.get 2 |> max 0
 
+    let lazyLoadWorkspace = "FSharp.lazyLoadWorkspace" |> Configuration.get false
+
     let isNetCoreApp (project: Project) =
         project.Info.TargetFramework :: project.Info.TargetFrameworks
         |> Seq.exists (fun tfm -> tfm = "net5.0" || tfm.StartsWith "netcoreapp")
@@ -106,8 +108,7 @@ module Project =
                 | Folder folder -> folder.Items |> Array.collect getProjs
 
             sln.Items |> Array.collect getProjs |> Array.toList
-        | Some(WorkspacePeekFound.Directory dir) -> dir.Fsprojs |> Array.toList
-
+        | Some(WorkspacePeekFound.Directory dir) -> dir.Fsprojs |> Array.map (fun f -> f.Path) |> Array.toList
 
     let getNotLoaded () =
         let lst =
@@ -250,7 +251,7 @@ module Project =
         let projs =
             match loadedWorkspace with
             | None -> Array.empty
-            | Some(WorkspacePeekFound.Directory dir) -> dir.Fsprojs
+            | Some(WorkspacePeekFound.Directory dir) -> dir.Fsprojs |> Array.map (fun f -> f.Path)
             | Some(WorkspacePeekFound.Solution sln) -> sln.Items |> Array.collect foldFsproj |> Array.map fst
 
         let loadingInProgress p =
@@ -545,7 +546,7 @@ module Project =
 
             let wdir =
                 { WorkspacePeekFoundDirectory.Directory = workspace.rootPath.Value
-                  Fsprojs = fsprojs |> Array.ofList }
+                  Fsprojs = fsprojs |> List.map (fun p -> { Path = p; CompileItems = [||] }) |> Array.ofList }
 
             return WorkspacePeekFound.Directory wdir
         }
@@ -642,30 +643,50 @@ module Project =
                 setAnyProjectContext true
         | None -> ()
 
-    let private initWorkspaceHelper x =
+    let private initWorkspaceHelper (context: ExtensionContext) x =
         clearLoadedProjects ()
         loadedWorkspace <- Some x
         workspaceChangedEmitter.fire x
 
         let projs =
             match x with
-            | WorkspacePeekFound.Directory dir -> dir.Fsprojs
-            | WorkspacePeekFound.Solution sln -> sln.Items |> Array.collect foldFsproj |> Array.map fst
+            | WorkspacePeekFound.Directory dir -> dir.Fsprojs |> Array.map (fun f -> (f.Path, f.CompileItems))
+            | WorkspacePeekFound.Solution sln -> sln.Items |> Array.collect foldFsproj |> Array.map (fun (p, _) -> (p, [||]))
 
         match x with
         | WorkspacePeekFound.Solution _ -> setAnyProjectContext true
         | WorkspacePeekFound.Directory _ when not (projs |> Array.isEmpty) -> setAnyProjectContext true
         | _ -> ()
 
-        projs |> List.ofArray |> LanguageService.workspaceLoad |> Promise.map ignore
+        if lazyLoadWorkspace then
+            //TODO: Register a file open event handler and load the project on demand
+            let fsFileToProj = Dictionary<string, string>()
+            for (proj, compileItems) in projs do
+                for compileItem in compileItems do
+                    fsFileToProj.[compileItem] <- proj
+
+            let openFileHandler (e: TextDocument) =
+
+                match tryFindInWorkspace e.uri.path with
+                | Some(ProjectLoadingState.Loaded _) -> ()
+                | Some(ProjectLoadingState.Loading _) -> ()
+                | _ -> LanguageService.workspaceLoad [ fsFileToProj[e.uri.path] ] |> ignore
+
+            // workspace.onDidOpenTextDocument $ (openFileHandler, (), context.subscriptions) |> ignore
+            workspace.onDidOpenTextDocument.Invoke(unbox openFileHandler)
+            |> context.Subscribe
+
+            Promise.lift ()
+        else
+            projs |> Array.map(fun (p, _) -> p) |> List.ofArray |> LanguageService.workspaceLoad |> Promise.map ignore
 
 
-    let initWorkspace () =
+    let initWorkspace (context: ExtensionContext) =
         getWorkspace ()
         |> Promise.bind (function
             | Some x -> Promise.lift x
             | None -> getWorkspaceForModeIonideSearch ())
-        |> Promise.bind (initWorkspaceHelper)
+        |> Promise.bind (initWorkspaceHelper context)
 
     module internal ProjectStatus =
         let mutable timer = None
@@ -744,7 +765,7 @@ module Project =
                 workspacePeek ()
                 |> Promise.bind (fun x -> pickFSACWorkspace x (CurrentWorkspaceConfiguration.get ()))
                 |> Promise.bind (function
-                    | Some w -> initWorkspaceHelper w
+                    | Some w -> initWorkspaceHelper context w
                     | None -> Promise.empty)
                 |> box
                 |> Some)
@@ -760,4 +781,4 @@ module Project =
         )
         |> context.Subscribe
 
-        initWorkspace ()
+        initWorkspace context

src/fsharp.fs

@@ -27,7 +27,7 @@ let private activateLanguageServiceRestart (context: ExtensionContext) =
             logger.Debug("Restarting F# language service")
             do! LanguageService.stop ()
             do! LanguageService.start context
-            do! Project.initWorkspace ()
+            do! Project.initWorkspace context
         }
 
     commands.registerCommand ("fsharp.restartLanguageService", restart |> objfy2)