Add a command to print the path of ocamllsp and ocamlformat executabl…

…es (#11243)

Signed-off-by: Sudha Parimala <sudharg247@gmail.com>

bin/tools/ocamlformat.ml

@@ -37,25 +37,42 @@ let build_dev_tool common =
      | Ok () -> ())
 ;;
 
-let term =
-  let+ builder = Common.Builder.term
-  and+ args = Arg.(value & pos_all string [] (info [] ~docv:"ARGS")) in
-  let common, config = Common.init builder in
-  Scheduler.go ~common ~config (fun () ->
-    let open Fiber.O in
-    let* () = Lock_dev_tool.lock_ocamlformat () |> Memo.run in
-    let+ () = build_dev_tool common in
-    run_dev_tool (Common.root common) ~args)
-;;
+module Exec = struct
+  let term =
+    let+ builder = Common.Builder.term
+    and+ args = Arg.(value & pos_all string [] (info [] ~docv:"ARGS")) in
+    let common, config = Common.init builder in
+    Scheduler.go ~common ~config (fun () ->
+      let open Fiber.O in
+      let* () = Lock_dev_tool.lock_ocamlformat () |> Memo.run in
+      let+ () = build_dev_tool common in
+      run_dev_tool (Common.root common) ~args)
+  ;;
 
-let info =
-  let doc =
-    {|Wrapper for running ocamlformat intended to be run automatically
-     by a text editor. All positional arguments will be passed to the
-     ocamlformat executable (pass flags to ocamlformat after the '--'
-     argument, such as 'dune ocamlformat -- --help').|}
-  in
-  Cmd.info "ocamlformat" ~doc
-;;
+  let info =
+    let doc =
+      {|Wrapper for running ocamlformat intended to be run automatically
+       by a text editor. All positional arguments will be passed to the
+       ocamlformat executable (pass flags to ocamlformat after the '--'
+       argument, such as 'dune ocamlformat -- --help').|}
+    in
+    Cmd.info "ocamlformat" ~doc
+  ;;
+
+  let command = Cmd.v info term
+end
+
+module Which = struct
+  let term =
+    let+ builder = Common.Builder.term in
+    let _ : Common.t * Dune_config_file.Dune_config.t = Common.init builder in
+    print_endline (Path.to_string exe_path)
+  ;;
+
+  let info =
+    let doc = {|Prints the path to the ocamlformat binary.|} in
+    Cmd.info "ocamlformat" ~doc
+  ;;
 
-let command = Cmd.v info term
+  let command = Cmd.v info term
+end

bin/tools/ocamlformat.mli

@@ -1,3 +1,9 @@
 open! Import
 
-val command : unit Cmd.t
+module Exec : sig
+  val command : unit Cmd.t
+end
+
+module Which : sig
+  val command : unit Cmd.t
+end

bin/tools/ocamllsp.ml

@@ -34,29 +34,46 @@ let is_in_dune_project builder =
   |> Result.is_ok
 ;;
 
-let term =
-  let+ builder = Common.Builder.term
-  and+ args = Arg.(value & pos_all string [] (info [] ~docv:"ARGS")) in
-  match is_in_dune_project builder with
-  | false ->
-    User_error.raise
-      [ Pp.textf
-          "Unable to run %s as a dev-tool because you don't appear to be inside a dune \
-           project."
-          ocamllsp_exe_name
-      ]
-  | true ->
-    let common, config = Common.init builder in
-    Scheduler.go ~common ~config (fun () ->
-      let open Fiber.O in
-      let* () = Lock_dev_tool.lock_ocamllsp () |> Memo.run in
-      let+ () = build_ocamllsp common in
-      run_ocamllsp (Common.root common) ~args)
-;;
+module Exec = struct
+  let term =
+    let+ builder = Common.Builder.term
+    and+ args = Arg.(value & pos_all string [] (info [] ~docv:"ARGS")) in
+    match is_in_dune_project builder with
+    | false ->
+      User_error.raise
+        [ Pp.textf
+            "Unable to run %s as a dev-tool because you don't appear to be inside a dune \
+             project."
+            ocamllsp_exe_name
+        ]
+    | true ->
+      let common, config = Common.init builder in
+      Scheduler.go ~common ~config (fun () ->
+        let open Fiber.O in
+        let* () = Lock_dev_tool.lock_ocamllsp () |> Memo.run in
+        let+ () = build_ocamllsp common in
+        run_ocamllsp (Common.root common) ~args)
+  ;;
 
-let info =
-  let doc = "Run ocamllsp, installing it as a dev tool if necessary." in
-  Cmd.info "ocamllsp" ~doc
-;;
+  let info =
+    let doc = "Run ocamllsp, installing it as a dev tool if necessary." in
+    Cmd.info "ocamllsp" ~doc
+  ;;
+
+  let command = Cmd.v info term
+end
+
+module Which = struct
+  let term =
+    let+ builder = Common.Builder.term in
+    let _ : Common.t * Dune_config_file.Dune_config.t = Common.init builder in
+    print_endline (Path.to_string ocamllsp_exe_path)
+  ;;
+
+  let info =
+    let doc = "Prints the path to the ocamllsp binary." in
+    Cmd.info "ocamllsp" ~doc
+  ;;
 
-let command = Cmd.v info term
+  let command = Cmd.v info term
+end

bin/tools/ocamllsp.mli

@@ -1,4 +1,13 @@
 open! Import
 
 (** Command to run ocamllsp, installing it if necessary *)
-val command : unit Cmd.t
+
+module Exec : sig
+  val command : unit Cmd.t
+end
+
+(** Command to print ocamllsp's path if exists *)
+
+module Which : sig
+  val command : unit Cmd.t
+end

bin/tools/tools.ml

@@ -3,9 +3,15 @@ open! Import
 module Exec = struct
   let doc = "Command group for running wrapped tools."
   let info = Cmd.info ~doc "exec"
-  let group = Cmd.group info [ Ocamlformat.command; Ocamllsp.command ]
+  let group = Cmd.group info [ Ocamlformat.Exec.command; Ocamllsp.Exec.command ]
+end
+
+module Which = struct
+  let doc = "Command group for printing the path to wrapped tools."
+  let info = Cmd.info ~doc "which"
+  let group = Cmd.group info [ Ocamlformat.Which.command; Ocamllsp.Which.command ]
 end
 
 let doc = "Command group for wrapped tools."
 let info = Cmd.info ~doc "tools"
-let group = Cmd.group info [ Exec.group ]
+let group = Cmd.group info [ Exec.group; Which.group ]

test/blackbox-tests/test-cases/pkg/dev-tools-which.t

@@ -0,0 +1,15 @@
+Tests for the `dune tools which` command.
+
+The ocamlformat case:
+  $ cat >dune-project <<EOF
+  > (lang dune 3.11)
+  > EOF
+  $ dune tools which ocamlformat
+  _build/_private/default/.dev-tool/ocamlformat/ocamlformat/target/bin/ocamlformat
+
+The ocamllsp case:
+  $ cat >dune-project <<EOF
+  > (lang dune 3.11)
+  > EOF
+  $ dune tools which ocamllsp
+  _build/_private/default/.dev-tool/ocaml-lsp-server/ocaml-lsp-server/target/bin/ocamllsp