Add ability to set Msbuild properties for design time

[Krzysztof-Cieslak]

Details

Should add ability to change the global properties we pass to design time loading.

Old proof of concept in #1065

Checklist

• I have looked through existing issues to make sure that this feature has not been requested before
• I have provided a descriptive title for this issue
• I am aware that even valid feature requests may be rejected if they do not align with the project's goals
• I or my company would be willing to contribute this feature

[github-actions]

🤖 This is an automated response from Repo Assist.

Great to see this is being tracked as a fresh issue! The old proof-of-concept PR #1065 had a solid design that's worth building on directly.

Implementation sketch

Based on the work in #1065, here's the core set of changes needed:

1. src/FsAutoComplete.Core/Consts.fs — change globalProperties from a list to a Map(string,string):

let globalProperties =
  Map.ofList [ ProduceReferenceAssembly, "false" ]

2. src/FsAutoComplete/LspHelpers.fs — add a BuildOptions config type (similar to FSACConfig):

type BuildOptionsDto =
  { MsBuildProperties: Dictionary(string, string) option }

type BuildOptions =
  { MsBuildProperties: Map(string, string) }
  static member Default = { MsBuildProperties = Map.empty }
  static member FromDto(dto: BuildOptionsDto) = ...
  member this.AddDto(dto: BuildOptionsDto) = ...

Then thread BuildOptions through FSharpConfigDto / FSharpConfig in the same pattern as FSACConfig.

3. src/FsAutoComplete/LspServers/AdaptiveFSharpLspServer.fs — change workspaceLoader parameter to a factory Map(string,string) -> IWorkspaceLoader, then make the loader reactive:

let loader =
  aval {
    let! factory = loaderFactory
    and! config = config
    return factory config.BuildOptions.MsBuildProperties
  }

This way, changing BuildOptions.MsBuildProperties via workspace/didChangeConfiguration automatically recreates the loader — and hence reloads all projects with the new properties.

4. src/FsAutoComplete/Parser.fs — update the workspaceLoaderFactory closure to accept props and merge with globalProperties:

fun toolsPath props ->
  let mergedProps = Map.merge ProjectLoader.globalProperties props |> Map.toList
  if projectGraphEnabled then
    WorkspaceLoaderViaProjectGraph.Create(toolsPath, mergedProps)
  else
    WorkspaceLoader.Create(toolsPath, mergedProps)

5. Tests — a good integration test scenario is: start with a project that has a #if RELEASE conditional; verify FSAC reports the symbol not found; then push a config change setting Configuration=Release; verify the symbol is now visible.

The client-side change (how editors surface this, e.g. FSharp.buildOptions.msBuildProperties: { "Configuration": "Release" }) is out of scope for FSAC itself — that would be an Ionide/editor extension change.

Happy to help flesh out any part of this further!

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