Allowing remote LSP connection in vscode API

sphinx/index.rst

@@ -21,6 +21,7 @@ Welcome to SuperBOL Studio OSS
    commands
    API doc <https://ocamlpro.github.io/superbol-studio-oss/doc>
    license
+   remote-lsp
 
    Sources and Issues on Github <https://github.com/ocamlpro/superbol-studio-oss>
 

sphinx/remote-lsp.rst

@@ -0,0 +1,25 @@
+.. remote-lsp
+
+You can simulate a remote LSP with the following scripts:
+
+Start a server on any port (here I chose 8000):
+`$ nc -k -l localhost 8000 > test.nc`
+
+Then, use the following script to read on a file:
+```
+touch $1
+inotifywait -m -e modify $1 | while read line
+do
+    if [ ! -s $1 ]; then
+       echo 'Waiting for content'
+    else
+	cat $1 | superbol lsp > superbol.log
+	> $1
+    fi
+done
+```
+
+and call it with `test.nc`.
+
+TODO: this script only receives information, but does not send it back to
+VSCODE; it only writes it in superbol.log. It should answer to the client.

src/lsp/superbol_free_lib/vscode_extension.ml

@@ -70,6 +70,7 @@ let package =
       "vscode-languageclient", "8.0.2";
       "polka", "^1.0.0-next.22";
       "sirv", "^2.0.2";
+      "ws", "^8.14.2";
 
       (* for the debug extension: *)
       "n-readlines", "^1.0.0";

src/vendor/vscode-ocaml-platform/src-bindings/node/node.ml

@@ -198,6 +198,8 @@ module Net = struct
   module Socket = struct
     include Class.Make ()
 
+    let to_ojs (t : t) : Ojs.t = (t :> Ojs.t)
+
     include
       [%js:
       val make : unit -> t [@@js.new "net.Socket"]

src/vendor/vscode-ocaml-platform/src-bindings/node/node.mli

@@ -156,6 +156,8 @@ module Net : sig
   module Socket : sig
     type t
 
+    val to_ojs : t -> Ojs.t
+
     val make : unit -> t
 
     val isPaused : t -> bool

src/vendor/vscode-ocaml-platform/src-bindings/vscode_languageclient/vscode_languageclient.ml

@@ -190,6 +190,26 @@ module StaticFeature = struct
       [@@js.builder]]
 end
 
+module StreamInfo = struct
+  include Interface.Make ()
+
+  include
+    [%js:
+    val writer : t -> Ojs.t [@@js.get]
+
+    val reader : t -> Ojs.t [@@js.get]
+
+    val detached : t -> bool option [@@js.get]
+
+    val create :
+         writer:Ojs.t
+      -> reader:Ojs.t
+      -> ?detached:bool
+      -> unit
+      -> t
+      [@@js.builder]]
+end
+
 module DidChangeConfiguration = struct
   include Interface.Make ()
 
@@ -211,6 +231,13 @@ module LanguageClient = struct
       -> t
       [@@js.new "vscode_languageclient.LanguageClient"]
 
+    val make_stream :
+         id:string
+      -> name:string
+      -> (unit -> StreamInfo.t Promise.t)
+      -> t
+      [@@js.new "vscode_languageclient.LanguageClient"]
+
     val start : t -> unit Promise.t [@@js.call]
 
     val isRunning : t -> bool [@@js.call]

src/vendor/vscode-ocaml-platform/src-bindings/vscode_languageclient/vscode_languageclient.mli

@@ -167,6 +167,24 @@ module DidChangeConfiguration : sig
   val create : settings:Ojs.t -> unit -> t
 end
 
+module StreamInfo: sig
+  include Js.T
+
+  val writer : t -> Ojs.t [@@js.get]
+
+  val reader : t -> Ojs.t [@@js.get]
+
+  val detached : t -> bool option [@@js.get]
+
+  val create :
+    writer:Ojs.t
+    -> reader:Ojs.t
+    -> ?detached:bool
+    -> unit
+    -> t
+         [@@js.builder]
+end
+
 module LanguageClient : sig
   include Js.T
 
@@ -179,6 +197,12 @@ module LanguageClient : sig
     -> unit
     -> t
 
+  val make_stream :
+    id:string
+    -> name:string
+    -> (unit -> StreamInfo.t Promise.t)
+    -> t
+
   val start : t -> unit Promise.t
 
   val isRunning : t -> bool

src/vendor/vscode-ocaml-platform/src-bindings/vscode_languageclient/vscode_languageclient_stub.js

@@ -1 +1,2 @@
 joo_global_object.vscode_languageclient = require("vscode-languageclient");
+// joo_global_object.webSocket = require("ws");

src/vscode/superbol-vscode-platform/superbol_instance.ml

@@ -20,6 +20,11 @@ type t = {
 }
 type client = LanguageClient.t
 
+
+let id = "superbol-free-lsp"
+
+let name = "SuperBOL Language Server"
+
 let make ~context = { context; language_client = None }
 
 let client { language_client; _ } = language_client
@@ -35,15 +40,47 @@ let stop_language_server t =
       else
         Promise.return ()
 
+let is_remote_lsp =
+  let prefix = "tcp://" in
+  fun serverOpt ->
+    let cmd = Executable.command serverOpt in
+    if String.starts_with ~prefix cmd then
+      let l = String.length prefix in
+      let url = String.sub cmd l (String.length cmd - l) in
+      Some url
+    else
+      None
+
+let host_and_port url =
+  let fail () = Format.ksprintf failwith "Invalid %S" url in
+  match String.split_on_char ':' url with
+  | [] | [_] -> fail ()
+  | host :: port :: _ ->
+    try host, int_of_string port with Invalid_argument _ -> fail ()
+
 let start_language_server ({ context; _ } as t) =
   let open Promise.Syntax in
   let* () = stop_language_server t in
+  let serverOptions =
+    Superbol_languageclient.server_options ~context
+  in
   let client =
-    LanguageClient.make ()
-      ~id: "superbol-free-lsp"
-      ~name: "SuperBOL Language Server"
-      ~serverOptions:(Superbol_languageclient.server_options ~context)
-      ~clientOptions:(Superbol_languageclient.client_options ())
+    match is_remote_lsp serverOptions with
+    | Some url ->
+      let host, port = host_and_port url in
+      LanguageClient.make_stream ~id ~name begin fun () ->
+        let socket =
+          (* Vscode_languageclient.StreamInfo.njs_stream_of_socket @@ *)
+          Node.Net.Socket.(to_ojs (connect (make ()) ~host ~port))
+        in
+        Promise.return @@
+        Vscode_languageclient.StreamInfo.create ()
+          ~writer:socket
+          ~reader:socket
+      end
+    | None ->
+      let clientOptions = Superbol_languageclient.client_options () in
+      LanguageClient.make () ~id ~name ~serverOptions ~clientOptions
   in
   let+ () = LanguageClient.start client in
   t.language_client <- Some client