`projectMapping` doesn't work for the first opened file

[khaledh]

I noticed that the first file I open in VSCode creates a nimsuggest process for that specific file, not the associated project file. When I later open other files, their nimsuggest instance uses the associated project file correctly.

// settings.json
{
  "nim.projectMapping": [
    {
        "projectFile": "src/kernel/main.nim",
        "fileRegex": "src/(kernel|common)/.*\\.nim"
    }
  ]
}

DBG Starting nimlangserver                     version=1.10.0 params="(clientProcessId: none(int), transport: some(stdio), port: 0)"
DBG Starting stdio server                     
DBG [Processsing Message]                      request="\"initialize\""
DBG Initialize received...                    
DBG Registering monitor for process            pid=84584
DBG Initialize completed. Trying to start nimsuggest instances
DBG Trying to start nimsuggest instances done 
DBG [Processsing Message]                      request="\"initialized\""
DBG Requesting configuration from the client  
DBG [Processsing Message]                      request="\"textDocument/didOpen\""
DBG New document opened for URI:               uri=file:///Users/khaled/src/khaledh/fusion/src/common/segtree.nim
DBG Auto-guessing project file for             file=/Users/khaled/src/khaledh/fusion/src/common/segtree.nim
DBG getProjectFile                             project=/Users/khaled/src/khaledh/fusion/src/common/segtree.nim fileUri=/Users/khaled/src/khaledh/fusion/src/common/segtree.nim

Notice that it says Auto-guessing project file, when it should rely on the project mapping config. The next file I open gets associated with the project file correctly:

DBG [Processsing Message]                      request="\"textDocument/didOpen\""
DBG New document opened for URI:               uri=file:///Users/khaled/src/khaledh/fusion/src/common/pagetables.nim
DBG ShowMessage                                message="RegEx matched `src/(kernel|common)/.*\\.nim` for file `/Users/khaled/src/khaledh/fusion/src/common/pagetables.nim`"
DBG Document associated with the following projectFile uri=file:///Users/khaled/src/khaledh/fusion/src/common/pagetables.nim projectFile=/Users/khaled/src/khaledh/fusion/src/kernel/main.nim

I looked at the langserver code, but it's not clear to me what might be the issue. I have a feeling it has to do with waiting on the workspace configuration future, which leads to this comment in getWorkspaceConfiguration:

    #this is the root of a lot a problems as there are multiple race conditions here.
    #since most request doenst really rely on the configuration, we can just go ahead and 
    #return a default one until we have the right one. 
    #TODO review and handle project specific confs when received instead of reliying in this func