feat(language-server): use a config variable to store configuration

changes

When using for example the neovim language server client, the contextive
language server does not acquire the proper settings sent by the client
in the `OnStarted` handler. However, the settings are passed correctly
using the `OnDidChangeConfiguration` handler.

This change introduces a scoped variable in the server start function to
hold a mutable field for the Contextive path configuration. The
configuration variable is initialized with the default path for
Contextive definitions introduced in commit 23f9049.

If the language configuration does not have a config value, it will use
the value from the configuration variable instead. This works the same
way as it did previously, but the source is now a parameter of the
function.

src/language-server/Contextive.LanguageServer/Configuration.fs

@@ -1,13 +1,18 @@
 module Contextive.LanguageServer.Configuration
 
 open System.Threading.Tasks
+open OmniSharp.Extensions.LanguageServer.Protocol.Models
 
 let resolvedPathGetter configGetter pathResolver () =
     async {
         let! path = configGetter ()
         return pathResolver path
     }
 
-let handler (definitionsLoader: Definitions.Reloader) _ =
+type Config = { mutable Path: string option }
+
+let handler (config: Config) (definitionsLoader: Definitions.Reloader) (configParams: DidChangeConfigurationParams) =
+    let path = configParams.Settings.Item("contextive").Item("path")
+    config.Path <- Some(path.ToString())
     definitionsLoader ()
     Task.CompletedTask

src/language-server/Contextive.LanguageServer/Definitions.fs

@@ -136,9 +136,7 @@ module private Handle =
         let matchOpenFileUri = matchGlobs findMsg.OpenFileUri
 
         let foundContexts =
-            state.Definitions.Contexts
-            |> Seq.filter matchOpenFileUri
-            |> findMsg.Filter
+            state.Definitions.Contexts |> Seq.filter matchOpenFileUri |> findMsg.Filter
 
         findMsg.ReplyChannel.Reply foundContexts
         state

src/language-server/Contextive.LanguageServer/Server.fs

@@ -25,7 +25,7 @@ let version =
         .GetCustomAttribute<AssemblyInformationalVersionAttribute>()
         .InformationalVersion
 
-let private getConfig (s: ILanguageServer) section key =
+let private getConfig (s: ILanguageServer) (contextiveConfig: Configuration.Config) section key =
     async {
         Log.Logger.Information $"Getting {section} {key} config..."
 
@@ -38,7 +38,7 @@ let private getConfig (s: ILanguageServer) section key =
         let value =
             if System.String.IsNullOrEmpty configValue then
                 match key with
-                | key when key = pathKey -> Some defaultContextiveDefinitionsPath
+                | key when key = pathKey -> contextiveConfig.Path
                 | _ -> None
             else
                 Some configValue
@@ -89,11 +89,13 @@ let private showSurveyPrompt (s: ILanguageServer) =
 let private onStartupShowSurveyPrompt =
     OnLanguageServerStartedDelegate(fun (s: ILanguageServer) _cancellationToken -> showSurveyPrompt (s))
 
-let private onStartupConfigureServer definitions =
+let private onStartupConfigureServer definitions config =
     OnLanguageServerStartedDelegate(fun (s: ILanguageServer) _cancellationToken ->
         async {
             s.Window.LogInfo $"Starting {name} v{version}..."
-            let configGetter () = getConfig s configSection pathKey
+
+            let configGetter () =
+                getConfig s config configSection pathKey
             // Not sure if this is needed to ensure configuration is loaded, or allow a task/context switch
             // Either way, if it's not here, then getWorkspaceFolder returns null
             let! _ = configGetter ()
@@ -122,15 +124,16 @@ let private onStartupConfigureServer definitions =
         |> Async.StartAsTask
         :> Task)
 
-
 let private configureServer (input: Stream) (output: Stream) (opts: LanguageServerOptions) =
     let definitions = Definitions.create ()
 
+    let contextiveConfig: Configuration.Config =
+        { Path = Some defaultContextiveDefinitionsPath }
+
     opts
         .WithInput(input)
         .WithOutput(output)
-
-        .OnStarted(onStartupConfigureServer definitions)
+        .OnStarted(onStartupConfigureServer definitions contextiveConfig)
         .OnStarted(onStartupShowSurveyPrompt)
         .WithConfigurationSection(configSection) // Add back in when implementing didConfigurationChanged handling
         .ConfigureLogging(fun z ->
@@ -141,7 +144,7 @@ let private configureServer (input: Stream) (output: Stream) (opts: LanguageServ
             |> ignore)
         .WithServerInfo(ServerInfo(Name = name, Version = version))
 
-        .OnDidChangeConfiguration(Configuration.handler <| Definitions.loader definitions)
+        .OnDidChangeConfiguration((Configuration.handler (contextiveConfig)) <| Definitions.loader definitions)
         .OnCompletion(
             Completion.handler <| Definitions.find definitions <| TextDocument.findToken,
             Completion.registrationOptions