Allowing remote LSP connection in vscode API

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## [0.1.4] Next release
 
 ### Added
+- Support for connecting to the LSP server remotely (TCP only) [#102](https://github.com/OCamlPro/superbol-studio-oss/pull/102)
 - Support for Symbol Renaming command [#351](https://github.com/OCamlPro/superbol-studio-oss/pull/351)
 - Show documentation comments on hover information [#350](https://github.com/OCamlPro/superbol-studio-oss/pull/350)
 - Completion for more grammar constructs [#322](https://github.com/OCamlPro/superbol-studio-oss/pull/322)

opam/vscode-languageclient-js-stubs.opam

@@ -49,6 +49,7 @@ depends: [
   "dune" {>= "2.8.0"}
   "vscode-js-stubs" {= version}
   "promise_jsoo" {>= "0.3.1" & < "1.0.0"}
+  "node-js-stubs" {= version}
   "jsonoo" {>= "0.2.1" & < "1.0.0"}
   "js_of_ocaml" {>= "4"}
   "interop-js-stubs" {= version}

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 +1,10 @@
+.. remote-lsp
+
+You can simulate a remote LSP with the following script:
+```
+$ mkfifo /tmp/somewhere # possibly in a directory resulting from `mktemp -d`
+$ nc -l 8000 < /tmp/somewhere | superbol-free lsp > /tmp/somewhere
+```
+
+Once this is running, you can enter `tcp://localhost:8000` in the `superbol.lsp-path` configuration setting. SuperBOL Studio will then rely on this LSP server instead of a binary that is bundled in the extension.
+Note: this "made up" remote server terminates once the first connection is closed.

src/lsp/superbol_free_lib/vscode_extension.ml

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

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

@@ -156,6 +156,9 @@ module Net : sig
   module Socket : sig
     type t
 
+    val t_of_js : Ojs.t -> t
+    val t_to_js : t -> Ojs.t
+
     val make : unit -> t
 
     val isPaused : t -> bool

src/vendor/vscode-ocaml-platform/src-bindings/vscode_languageclient/package.toml

@@ -59,6 +59,7 @@ js_of_ocaml = ">=4"
 jsonoo = "0.2.1"
 promise_jsoo = "0.3.1"
 vscode-js-stubs = "version"
+node-js-stubs = "version"
 
 # package tools dependencies
 [tools]

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 -> Node.Net.Socket.t [@@js.get]
+
+    val reader : t -> Node.Net.Socket.t [@@js.get]
+
+    val detached : t -> bool option [@@js.get]
+
+    val create :
+         writer: Node.Net.Socket.t
+      -> reader: Node.Net.Socket.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 from_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 -> Node.Net.Socket.t [@@js.get]
+
+  val reader : t -> Node.Net.Socket.t [@@js.get]
+
+  val detached : t -> bool option [@@js.get]
+
+  val create :
+    writer: Node.Net.Socket.t
+    -> reader: Node.Net.Socket.t
+    -> ?detached:bool
+    -> unit
+    -> t
+         [@@js.builder]
+end
+
 module LanguageClient : sig
   include Js.T
 
@@ -179,6 +197,12 @@ module LanguageClient : sig
     -> unit
     -> t
 
+  val from_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

@@ -20,9 +20,16 @@ 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
+let subscribe_disposable { context; _ } disposable =
+  Vscode.ExtensionContext.subscribe context ~disposable
 
 let stop_language_server t =
   match t.language_client with
@@ -39,16 +46,31 @@ let start_language_server ({ context; _ } as t) =
   let open Promise.Syntax in
   let* () = stop_language_server t 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 Superbol_languageclient.server_access ~context with
+    | Sub_process serverOptions ->
+        LanguageClient.make () ~id ~name ~serverOptions
+          ~clientOptions:(Superbol_languageclient.client_options ())
+    | TCP { host; port } ->
+        LanguageClient.from_stream ~id ~name begin fun () ->
+          let socket = Node.Net.Socket.(connect (make ())) ~host ~port in
+          Node.Net.Socket.on socket @@ `Connect begin fun () ->
+            subscribe_disposable t @@
+            Vscode.Window.setStatusBarMessage ()
+              ~text:(Printf.sprintf "SuperBOL LSP client successfully connected \
+                                     to %s on port %u" host port)
+              ~hide:(`AfterTimeout 10000)
+          end;
+          Promise.return @@
+          Vscode_languageclient.StreamInfo.create ()
+            ~writer:socket
+            ~reader:socket
+        end
   in
   let+ () = LanguageClient.start client in
   t.language_client <- Some client
 
 
+
 let current_document_uri ?text_editor () =
   match
     match text_editor with None -> Vscode.Window.activeTextEditor () | e -> e

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

@@ -16,6 +16,7 @@ type t
 type client = Vscode_languageclient.LanguageClient.t
 
 val make: context:Vscode.ExtensionContext.t -> t
+val subscribe_disposable: t -> Vscode.Disposable.t -> unit
 
 val stop_language_server: t -> unit Promise.t
 val start_language_server: t -> unit Promise.t

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

@@ -14,6 +14,10 @@
 
 module LSP = Vscode_languageclient
 
+type server_access =
+  | Sub_process of LSP.ServerOptions.t
+  | TCP of { host: string; port: int }
+
 
 (* Helpers to find the bundled superbol executable *)
 let rec find_existing = function
@@ -48,7 +52,26 @@ let find_superbol root =
   ]
 
 
-let server_options ~context =
+let scan_host_and_port url =
+  let fail () = Format.ksprintf failwith "Invalid %S" url in
+  match String.split_on_char ':' url with
+  | [host; port] ->
+      (try TCP { host; port = int_of_string port }
+       with Invalid_argument _ -> fail ())
+  | _ ->
+      fail ()
+
+let scan_server_command cmd =
+  let prefix = "tcp://" 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 (scan_host_and_port url)
+  else
+    None
+
+
+let server_command ~context ?cmd () =
   let root_uri = Vscode.ExtensionContext.extensionUri context
   and storage_uri =
     (* Use the global state URI as the server stores caches on a per-project
@@ -59,7 +82,7 @@ let server_options ~context =
     else None
   in
   let command =
-    match Superbol_workspace.superbol_exe () with
+    match cmd with
     | Some cmd ->
         cmd
     | None ->
@@ -85,8 +108,17 @@ let server_options ~context =
      | None -> []
      | Some uri -> ["--storage-directory"; Vscode.Uri.fsPath uri])
   in
-  LSP.ServerOptions.create ()
-    ~options ~command ~args
+  Sub_process (LSP.ServerOptions.create ~options ~command ~args ())
+
+
+let server_access ~context =
+  match Superbol_workspace.superbol_exe () with
+  | None ->
+      server_command ~context ()
+  | Some cmd ->
+      match scan_server_command cmd with
+      | Some access -> access
+      | None -> server_command ~context ~cmd ()
 
 
 let client_options () =

src/vscode/superbol-vscode-platform/superbol_languageclient.mli

@@ -12,9 +12,13 @@
 (*                                                                        *)
 (**************************************************************************)
 
-val server_options
+type server_access =
+  | Sub_process of Vscode_languageclient.ServerOptions.t
+  | TCP of { host: string; port: int }
+
+val server_access
   : context: Vscode.ExtensionContext.t
-  -> Vscode_languageclient.ServerOptions.t
+  -> server_access
 
 val client_options
   : unit

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

@@ -12,20 +12,20 @@
 (*                                                                        *)
 (**************************************************************************)
 
-let lsp_server_autorestarter instance : Vscode.Disposable.t =
+let start_lsp_server_autorestarter instance =
+  Superbol_instance.subscribe_disposable instance @@
   Vscode.Workspace.onDidChangeConfiguration ()
     ~listener:begin fun config_change ->
       if Superbol_languageclient.server_needs_restart_after ~config_change
-      then
-        let _ =
-          Vscode.Window.setStatusBarMessage ()
-            ~text:"Restarting SuperBOL Language Server…"
-            ~hide:(`AfterTimeout 2000)
-        in
-        let _: unit Promise.t =
+      then begin
+        Superbol_instance.subscribe_disposable instance @@
+        Vscode.Window.setStatusBarMessage ()
+          ~text:"Restarting SuperBOL Language Server…"
+          ~hide:(`AfterTimeout 2000);
+        let _ : unit Promise.t =
           Superbol_instance.start_language_server instance
         in ()
-      else ()
+      end;
     end
 
 (* --- *)
@@ -36,15 +36,11 @@ let activate (extension: Vscode.ExtensionContext.t) =
   let instance = Superbol_instance.make ~context:extension in
   current_instance := Some instance;
 
-  let task =
-    Vscode.Tasks.registerTaskProvider
-      ~type_:Superbol_tasks.type_
-      ~provider:(Superbol_tasks.provider instance)
-  in
-  Vscode.ExtensionContext.subscribe extension ~disposable:task;
-
-  Vscode.ExtensionContext.subscribe extension
-    ~disposable:(lsp_server_autorestarter instance);
+  Superbol_instance.subscribe_disposable instance @@
+  Vscode.Tasks.registerTaskProvider
+    ~type_:Superbol_tasks.type_
+    ~provider:(Superbol_tasks.provider instance);
+  start_lsp_server_autorestarter instance;
 
   Superbol_commands.register_all extension instance;
   Superbol_instance.start_language_server instance