From 0c44fb83b526169757fdf07916d6d4ec715f40e0 Mon Sep 17 00:00:00 2001
From: Hyeseong Kim <hey@hyeseong.kim>
Date: Mon, 4 Sep 2023 22:31:56 +0900
Subject: [PATCH 1/4] add support rescript.json

---
 jscomp/bsb/bsb_build_util.ml           | 15 +++++-----
 jscomp/bsb/bsb_config_load.ml          | 25 +++++++++++++++++
 jscomp/bsb/bsb_config_load.mli         |  2 ++
 jscomp/bsb/bsb_config_parse.ml         | 30 ++++++++++----------
 jscomp/bsb/bsb_config_parse.mli        |  2 +-
 jscomp/bsb/bsb_config_types.ml         |  2 ++
 jscomp/bsb/bsb_ninja_regen.ml          |  6 ++--
 jscomp/bsb/bsb_ninja_regen.mli         |  1 +
 jscomp/bsb/bsb_world.ml                |  3 +-
 jscomp/bsb_exe/rescript_main.ml        | 21 ++++++++++----
 jscomp/ext/ext_path.ml                 | 29 +++++++++++---------
 jscomp/ext/ext_path.mli                | 20 +++++++-------
 jscomp/ext/literals.ml                 |  2 ++
 jscomp/gentype/GenTypeConfig.ml        | 14 ++++++----
 jscomp/gentype/Paths.ml                | 16 +++++++----
 jscomp/runtime/release.ninja           |  6 ++--
 jscomp/syntax/src/reactjs_jsx_ppx.mli  |  2 +-
 jscomp/syntax/src/res_multi_printer.ml | 38 +++++++++++++++-----------
 rescript                               | 20 +++++++++-----
 19 files changed, 161 insertions(+), 93 deletions(-)
 create mode 100644 jscomp/bsb/bsb_config_load.ml
 create mode 100644 jscomp/bsb/bsb_config_load.mli

diff --git a/jscomp/bsb/bsb_build_util.ml b/jscomp/bsb/bsb_build_util.ml
index 8d49c183fe..9982b5b65b 100644
--- a/jscomp/bsb/bsb_build_util.ml
+++ b/jscomp/bsb/bsb_build_util.ml
@@ -17,7 +17,7 @@
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU Lesser General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU Lesser General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *)
@@ -101,7 +101,7 @@ let resolve_bsb_magic_file ~cwd ~desc p : result =
 
 (** converting a file from Linux path format to Windows *)
 
-(** 
+(**
    {[
      mkp "a/b/c/d";;
      mkp "/a/b/c/d"
@@ -155,9 +155,8 @@ let extract_pinned_dependencies (map : Ext_json_types.t Map_string.t) : Set_stri
 
 let rec walk_all_deps_aux (visited : string Hash_string.t) (paths : string list)
     ~(top : top) (dir : string) (queue : _ Queue.t) ~pinned_dependencies =
-  let bsconfig_json = dir // Literals.bsconfig_json in
-  match Ext_json_parse.parse_json_from_file bsconfig_json with
-  | Obj { map; loc } ->
+  match Bsb_config_load.load_json ~per_proj_dir:dir ~warn_legacy_config:false with
+  | _, Obj { map; loc } ->
       let cur_package_name =
         match Map_string.find_opt map Bsb_build_schemas.name with
         | Some (Str { str; loc }) ->
@@ -183,7 +182,7 @@ let rec walk_all_deps_aux (visited : string Hash_string.t) (paths : string list)
       else
         let explore_deps (deps : string) pinned_dependencies =
           map
-          |? ( deps,                
+          |? ( deps,
                `Arr
                  (fun (new_packages : Ext_json_types.t array) ->
                    Ext_array.iter new_packages (fun js ->
@@ -205,8 +204,8 @@ let rec walk_all_deps_aux (visited : string Hash_string.t) (paths : string list)
         | Expect_name n when Set_string.mem pinned_dependencies n -> true
         | _ -> false
         in
-        let pinned_dependencies = match is_pinned with 
-        | true -> 
+        let pinned_dependencies = match is_pinned with
+        | true ->
           let transitive_pinned_dependencies = extract_pinned_dependencies map
           in
           Set_string.union transitive_pinned_dependencies pinned_dependencies
diff --git a/jscomp/bsb/bsb_config_load.ml b/jscomp/bsb/bsb_config_load.ml
new file mode 100644
index 0000000000..e947c920ed
--- /dev/null
+++ b/jscomp/bsb/bsb_config_load.ml
@@ -0,0 +1,25 @@
+let ( // ) = Ext_path.combine
+
+let load_json ~(per_proj_dir : string) ~(warn_legacy_config : bool)
+    : string * Ext_json_types.t =
+  let filename, abs, in_chan =
+    let filename = Literals.rescript_json in
+    let abs = (per_proj_dir // filename) in
+    match open_in abs
+    with
+    | in_chan -> (filename, abs, in_chan)
+    | exception e ->
+      let filename = Literals.bsconfig_json in
+      let abs = (per_proj_dir // filename) in
+      match open_in abs
+      with
+      | in_chan -> (filename, abs, in_chan)
+      | exception _ -> raise e (* forward error from rescript.json *)
+  in
+  if warn_legacy_config && filename = Literals.bsconfig_json then
+    (* TODO: warn legacy config *)
+    ();
+  match Ext_json_parse.parse_json_from_chan abs in_chan
+  with
+  | v -> close_in in_chan ; (filename, v)
+  | exception e -> close_in in_chan ; raise e
diff --git a/jscomp/bsb/bsb_config_load.mli b/jscomp/bsb/bsb_config_load.mli
new file mode 100644
index 0000000000..7e8cd97857
--- /dev/null
+++ b/jscomp/bsb/bsb_config_load.mli
@@ -0,0 +1,2 @@
+val load_json :
+  per_proj_dir:string -> warn_legacy_config:bool -> string * Ext_json_types.t
diff --git a/jscomp/bsb/bsb_config_parse.ml b/jscomp/bsb/bsb_config_parse.ml
index 0ef2c2da33..1a6f654ba7 100644
--- a/jscomp/bsb/bsb_config_parse.ml
+++ b/jscomp/bsb/bsb_config_parse.ml
@@ -70,10 +70,10 @@ let extract_package_name_and_namespace (map : json_map) : string * string option
    - the running bsb need delete stale build artifacts
       (kinda check npm upgrade)
 
-      Note if the setup is correct: 
+      Note if the setup is correct:
       the running compiler and node_modules/rescript
-      should be the same version, 
-      The exact check is that the running compiler should have a 
+      should be the same version,
+      The exact check is that the running compiler should have a
       compatible runtime version installed, the location of the
       compiler is actually not relevant.
       We disable the check temporarily
@@ -235,9 +235,9 @@ let extract_js_post_build (map : json_map) cwd : string option =
   |> ignore;
   !js_post_build_cmd
 
-(** ATT: make sure such function is re-entrant. 
+(** ATT: make sure such function is re-entrant.
     With a given [cwd] it works anywhere*)
-let interpret_json ~(package_kind : Bsb_package_kind.t) ~(per_proj_dir : string)
+let interpret_json ~(package_kind : Bsb_package_kind.t) ~(per_proj_dir : string) ~(warn_legacy_config : bool)
     : Bsb_config_types.t =
   (* we should not resolve it too early,
       since it is external configuration, no {!Bsb_build_util.convert_and_resolve_path}
@@ -254,9 +254,9 @@ let interpret_json ~(package_kind : Bsb_package_kind.t) ~(per_proj_dir : string)
      2. we need store it so that we can call ninja correctly
   *)
   match
-    Ext_json_parse.parse_json_from_file (per_proj_dir // Literals.bsconfig_json)
+    Bsb_config_load.load_json ~per_proj_dir ~warn_legacy_config
   with
-  | Obj { map } -> (
+  | filename, Obj { map } -> (
       let package_name, namespace = extract_package_name_and_namespace map in
       let gentype_config = extract_gentype_config map in
 
@@ -349,17 +349,19 @@ let interpret_json ~(package_kind : Bsb_package_kind.t) ~(per_proj_dir : string)
             (match package_kind with
             | Toplevel -> extract_uncurried map
             | Pinned_dependency x | Dependency x -> x.uncurried);
+            filename;
           }
       | None ->
-          Bsb_exception.invalid_spec "no sources specified in bsconfig.json")
-  | _ -> Bsb_exception.invalid_spec "bsconfig.json expect a json object {}"
+          Bsb_exception.invalid_spec ("no sources specified in " ^ filename))
+  | filename, _ -> Bsb_exception.invalid_spec (filename ^ " expect a json object {}")
 
 let deps_from_bsconfig () =
-  let json = Ext_json_parse.parse_json_from_file Literals.bsconfig_json in
-  match json with
-  | Obj { map } ->
-      ( Bsb_package_specs.from_map ~cwd:Bsb_global_paths.cwd map,
+  let cwd = Bsb_global_paths.cwd in
+  match Bsb_config_load.load_json ~per_proj_dir:cwd ~warn_legacy_config:false
+  with
+  | _, Obj { map } ->
+      ( Bsb_package_specs.from_map ~cwd map,
         Bsb_jsx.from_map map,
         extract_uncurried map,
         Bsb_build_util.extract_pinned_dependencies map )
-  | _ -> assert false
+  | _, _ -> assert false
diff --git a/jscomp/bsb/bsb_config_parse.mli b/jscomp/bsb/bsb_config_parse.mli
index 3ce5d5e166..84e18eb1ff 100644
--- a/jscomp/bsb/bsb_config_parse.mli
+++ b/jscomp/bsb/bsb_config_parse.mli
@@ -25,4 +25,4 @@
 val deps_from_bsconfig : unit -> Bsb_package_specs.t * Bsb_jsx.t * bool *  Set_string.t
 
 val interpret_json :
-  package_kind:Bsb_package_kind.t -> per_proj_dir:string -> Bsb_config_types.t
+  package_kind:Bsb_package_kind.t -> per_proj_dir:string -> warn_legacy_config:bool -> Bsb_config_types.t
diff --git a/jscomp/bsb/bsb_config_types.ml b/jscomp/bsb/bsb_config_types.ml
index 4404ad727d..db5c007e4d 100644
--- a/jscomp/bsb/bsb_config_types.ml
+++ b/jscomp/bsb/bsb_config_types.ml
@@ -65,4 +65,6 @@ type t = {
   (* note when used as a dev mode, we will always ignore it *)
   gentype_config : gentype_config;
   uncurried: bool;
+
+  filename: string;
 }
diff --git a/jscomp/bsb/bsb_ninja_regen.ml b/jscomp/bsb/bsb_ninja_regen.ml
index 9481d6cb63..009918d8c1 100644
--- a/jscomp/bsb/bsb_ninja_regen.ml
+++ b/jscomp/bsb/bsb_ninja_regen.ml
@@ -30,7 +30,7 @@ let ( // ) = Ext_path.combine
     return None if we dont need regenerate
     otherwise return Some info
 *)
-let regenerate_ninja ~(package_kind : Bsb_package_kind.t) ~forced ~per_proj_dir
+let regenerate_ninja ~(package_kind : Bsb_package_kind.t) ~forced ~per_proj_dir ~warn_legacy_config
     : Bsb_config_types.t option =
   let lib_artifacts_dir = Bsb_config.lib_bs in
   let lib_bs_dir = per_proj_dir // lib_artifacts_dir in
@@ -52,7 +52,7 @@ let regenerate_ninja ~(package_kind : Bsb_package_kind.t) ~forced ~per_proj_dir
         Bsb_clean.clean_self per_proj_dir);
 
       let config : Bsb_config_types.t =
-        Bsb_config_parse.interpret_json ~package_kind ~per_proj_dir
+        Bsb_config_parse.interpret_json ~package_kind ~per_proj_dir ~warn_legacy_config
       in
       (* create directory, lib/bs, lib/js, lib/es6 etc *)
       Bsb_build_util.mkp lib_bs_dir;
@@ -75,5 +75,5 @@ let regenerate_ninja ~(package_kind : Bsb_package_kind.t) ~forced ~per_proj_dir
           since it may add files in the future *)
       Bsb_ninja_check.record ~package_kind ~per_proj_dir ~config
         ~file:output_deps
-        (Literals.bsconfig_json :: config.file_groups.globbed_dirs);
+        (config.filename :: config.file_groups.globbed_dirs);
       Some config
diff --git a/jscomp/bsb/bsb_ninja_regen.mli b/jscomp/bsb/bsb_ninja_regen.mli
index 5409f022f9..b92cf0b115 100644
--- a/jscomp/bsb/bsb_ninja_regen.mli
+++ b/jscomp/bsb/bsb_ninja_regen.mli
@@ -26,6 +26,7 @@ val regenerate_ninja :
   package_kind:Bsb_package_kind.t ->
   forced:bool ->
   per_proj_dir:string ->
+  warn_legacy_config:bool ->
   Bsb_config_types.t option
 (** Regenerate ninja file by need based on [.bsdeps]
     return None if we dont need regenerate
diff --git a/jscomp/bsb/bsb_world.ml b/jscomp/bsb/bsb_world.ml
index df6cdf747a..e5e9dfdc77 100644
--- a/jscomp/bsb/bsb_world.ml
+++ b/jscomp/bsb/bsb_world.ml
@@ -30,7 +30,7 @@ let make_world_deps cwd (config : Bsb_config_types.t option)
   let package_specs, jsx, uncurried, pinned_dependencies =
     match config with
     | None ->
-        (* When this running bsb does not read bsconfig.json,
+        (* When this running bsb does not read rescript.json,
            we will read such json file to know which [package-specs]
            it wants
         *)
@@ -70,6 +70,7 @@ let make_world_deps cwd (config : Bsb_config_types.t option)
                    (if is_pinned then Pinned_dependency { package_specs; jsx; uncurried }
                    else Dependency { package_specs; jsx; uncurried })
                  ~per_proj_dir:proj_dir ~forced:false
+                 ~warn_legacy_config:false
              in
              let command =
                { Bsb_unix.cmd = vendor_ninja; cwd = lib_bs_dir; args }
diff --git a/jscomp/bsb_exe/rescript_main.ml b/jscomp/bsb_exe/rescript_main.ml
index 799266ff26..b9050b5700 100644
--- a/jscomp/bsb_exe/rescript_main.ml
+++ b/jscomp/bsb_exe/rescript_main.ml
@@ -142,8 +142,12 @@ let build_subcommand ~start argv argv_len =
   | [| "-h" |] -> ninja_command_exit ninja_args
   | _ ->
       let config_opt =
-        Bsb_ninja_regen.regenerate_ninja ~package_kind:Toplevel
-          ~per_proj_dir:Bsb_global_paths.cwd ~forced:!force_regenerate in
+        Bsb_ninja_regen.regenerate_ninja
+          ~package_kind:Toplevel
+          ~per_proj_dir:Bsb_global_paths.cwd
+          ~forced:!force_regenerate
+          ~warn_legacy_config:true
+        in
       if not !no_deps_mode then Bsb_world.make_world_deps Bsb_global_paths.cwd config_opt ninja_args;
       if !do_install then install_target ();
       ninja_command_exit ninja_args
@@ -171,8 +175,11 @@ let info_subcommand ~start argv =
       | [] -> ());
       if !list_files then
         match
-          Bsb_ninja_regen.regenerate_ninja ~package_kind:Toplevel ~forced:true
+          Bsb_ninja_regen.regenerate_ninja
+            ~package_kind:Toplevel
             ~per_proj_dir:Bsb_global_paths.cwd
+            ~forced:true
+            ~warn_legacy_config:true
         with
         | None -> assert false
         | Some { file_groups = { files } } ->
@@ -198,8 +205,12 @@ let () =
     if argv_len = 1 then (
       (* specialize this path which is used in watcher *)
       let config_opt =
-        Bsb_ninja_regen.regenerate_ninja ~package_kind:Toplevel ~forced:false
-          ~per_proj_dir:Bsb_global_paths.cwd in
+        Bsb_ninja_regen.regenerate_ninja
+          ~package_kind:Toplevel
+          ~per_proj_dir:Bsb_global_paths.cwd
+          ~forced:false
+          ~warn_legacy_config:true
+      in
       Bsb_world.make_world_deps Bsb_global_paths.cwd config_opt [||];
       ninja_command_exit [||])
     else
diff --git a/jscomp/ext/ext_path.ml b/jscomp/ext/ext_path.ml
index 6b1ec82e8d..31bbe47a67 100644
--- a/jscomp/ext/ext_path.ml
+++ b/jscomp/ext/ext_path.ml
@@ -1,5 +1,5 @@
 (* Copyright (C) 2017 Hongbo Zhang, Authors of ReScript
- * 
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
@@ -17,7 +17,7 @@
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU Lesser General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU Lesser General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *)
@@ -117,7 +117,7 @@ let ( // ) x y =
      split_aux "//ghosg//ghsogh/";;
      - : string * string list = ("/", ["ghosg"; "ghsogh"])
    ]}
-   Note that 
+   Note that
    {[
      Filename.dirname "/a/" = "/"
        Filename.dirname "/a/b/" = Filename.dirname "/a/b" = "/a"
@@ -132,7 +132,7 @@ let ( // ) x y =
        basename "" = "."
        dirname "" = "."
        dirname "" =  "."
-   ]}  
+   ]}
 *)
 let split_aux p =
   let rec go p acc =
@@ -149,11 +149,11 @@ let split_aux p =
 
   go p []
 
-(** 
+(**
    TODO: optimization
-   if [from] and [to] resolve to the same path, a zero-length string is returned 
+   if [from] and [to] resolve to the same path, a zero-length string is returned
 
-   This function is useed in [es6-global] and 
+   This function is useed in [es6-global] and
    [amdjs-global] format and tailored for `rollup`
 *)
 let rel_normalized_absolute_path ~from to_ =
@@ -261,14 +261,17 @@ let concat dirname filename =
 let check_suffix_case = Ext_string.ends_with
 
 (* Input must be absolute directory *)
-let rec find_root_filename ~cwd filename =
-  if Sys.file_exists (Filename.concat cwd filename) then cwd
+let rec find_root_filename ~cwd filenames =
+  let file_exists = Ext_list.exists filenames (fun filename ->
+    Sys.file_exists (Filename.concat cwd filename))
+  in
+  if file_exists then cwd
   else
     let cwd' = Filename.dirname cwd in
     if String.length cwd' < String.length cwd then
-      find_root_filename ~cwd:cwd' filename
-    else Ext_fmt.failwithf ~loc:__LOC__ "%s not found from %s" filename cwd
+      find_root_filename ~cwd:cwd' filenames
+    else Ext_fmt.failwithf ~loc:__LOC__ "%s not found from %s" (List.hd filenames) cwd
 
-let find_package_json_dir cwd = find_root_filename ~cwd Literals.bsconfig_json
+let find_config_dir cwd = find_root_filename ~cwd [Literals.rescript_json; Literals.bsconfig_json]
 
-let package_dir = lazy (find_package_json_dir (Lazy.force cwd))
+let package_dir = lazy (find_config_dir (Lazy.force cwd))
diff --git a/jscomp/ext/ext_path.mli b/jscomp/ext/ext_path.mli
index 76e6e209c9..6a9905688a 100644
--- a/jscomp/ext/ext_path.mli
+++ b/jscomp/ext/ext_path.mli
@@ -1,5 +1,5 @@
 (* Copyright (C) 2017 Authors of ReScript
- * 
+ *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
@@ -17,7 +17,7 @@
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU Lesser General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU Lesser General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *)
@@ -25,11 +25,11 @@
 type t
 
 val simple_convert_node_path_to_os_path : string -> string
-(** Js_output is node style, which means 
+(** Js_output is node style, which means
     separator is only '/'
 
-    if the path contains 'node_modules', 
-    [node_relative_path] will discard its prefix and 
+    if the path contains 'node_modules',
+    [node_relative_path] will discard its prefix and
     just treat it as a library instead
 *)
 
@@ -50,14 +50,14 @@ val combine : string -> string -> string
 val node_rebase_file : from:string -> to_:string -> string -> string
 
 val rel_normalized_absolute_path : from:string -> string -> string
-(** 
+(**
    TODO: could be highly optimized
-   if [from] and [to] resolve to the same path, a zero-length string is returned 
+   if [from] and [to] resolve to the same path, a zero-length string is returned
    Given that two paths are directory
 
-   A typical use case is 
+   A typical use case is
    {[
-     Filename.concat 
+     Filename.concat
        (rel_normalized_absolute_path cwd (Filename.dirname a))
        (Filename.basename a)
    ]}
@@ -69,7 +69,7 @@ val absolute_cwd_path : string -> string
 
 val concat : string -> string -> string
 (** [concat dirname filename]
-    The same as {!Filename.concat} except a tiny optimization 
+    The same as {!Filename.concat} except a tiny optimization
     for current directory simplification
 *)
 
diff --git a/jscomp/ext/literals.ml b/jscomp/ext/literals.ml
index 6810267cf5..ed410ee8d7 100644
--- a/jscomp/ext/literals.ml
+++ b/jscomp/ext/literals.ml
@@ -76,6 +76,8 @@ let package_json = "package.json"
 
 let bsconfig_json = "bsconfig.json"
 
+let rescript_json = "rescript.json"
+
 let build_ninja = "build.ninja"
 
 (* Name of the library file created for each external dependency. *)
diff --git a/jscomp/gentype/GenTypeConfig.ml b/jscomp/gentype/GenTypeConfig.ml
index 125d94fb5c..299e52f945 100644
--- a/jscomp/gentype/GenTypeConfig.ml
+++ b/jscomp/gentype/GenTypeConfig.ml
@@ -101,10 +101,14 @@ let setDebug ~gtconf =
   | Some (Obj {map}) -> Map_string.iter map Debug.setItem
   | _ -> ()
 
-let compilerConfigFile = "bsconfig.json"
+let compilerConfigFile = "rescript.json"
+let legacyCompilerConfigFile = "bsconfig.json"
 
 let rec findProjectRoot ~dir =
-  if Sys.file_exists (Filename.concat dir compilerConfigFile) then dir
+  if
+    Sys.file_exists (Filename.concat dir compilerConfigFile)
+    || Sys.file_exists (Filename.concat dir legacyCompilerConfigFile)
+  then dir
   else
     let parent = dir |> Filename.dirname in
     if parent = dir then (
@@ -114,7 +118,7 @@ let rec findProjectRoot ~dir =
       assert false)
     else findProjectRoot ~dir:parent
 
-let readConfig ~getBsConfigFile ~namespace =
+let readConfig ~getConfigFile ~namespace =
   let projectRoot = findProjectRoot ~dir:(Sys.getcwd ()) in
   let bsbProjectRoot =
     match Sys.getenv_opt "BSB_PROJECT_ROOT" with
@@ -175,7 +179,7 @@ let readConfig ~getBsConfigFile ~namespace =
       | Some externalStdlib -> externalStdlib
     in
     if !Debug.config then (
-      Log_.item "Project root: %s\n" projectRoot;
+      Log_.item "Project roLiterals.bsconfig_jsonot: %s\n" projectRoot;
       if bsbProjectRoot <> projectRoot then
         Log_.item "bsb project root: %s\n" bsbProjectRoot;
       Log_.item "Config module:%s shims:%d entries \n"
@@ -230,7 +234,7 @@ let readConfig ~getBsConfigFile ~namespace =
       sources;
     }
   in
-  match getBsConfigFile ~projectRoot with
+  match getConfigFile ~projectRoot with
   | Some bsConfigFile -> (
     try
       let json = bsConfigFile |> Ext_json_parse.parse_json_from_file in
diff --git a/jscomp/gentype/Paths.ml b/jscomp/gentype/Paths.ml
index b64b5c0b36..ed95905268 100644
--- a/jscomp/gentype/Paths.ml
+++ b/jscomp/gentype/Paths.ml
@@ -61,10 +61,14 @@ let getCmtFile cmt =
   in
   cmtFile
 
-let getBsConfigFile ~projectRoot =
-  let bsconfig = concat projectRoot Config.compilerConfigFile in
-  match bsconfig |> Sys.file_exists with
-  | true -> Some bsconfig
-  | false -> None
+let getConfigFile ~projectRoot =
+  let config = concat projectRoot Config.compilerConfigFile in
+  match config |> Sys.file_exists with
+  | true -> Some config
+  | false -> (
+    let config = concat projectRoot Config.legacyCompilerConfigFile in
+    match config |> Sys.file_exists with
+    | true -> Some config
+    | false -> None)
 
-let readConfig ~namespace = Config.readConfig ~getBsConfigFile ~namespace
+let readConfig ~namespace = Config.readConfig ~getConfigFile ~namespace
diff --git a/jscomp/runtime/release.ninja b/jscomp/runtime/release.ninja
index b7b44625e4..181ca9fa81 100644
--- a/jscomp/runtime/release.ninja
+++ b/jscomp/runtime/release.ninja
@@ -21,7 +21,7 @@ o runtime/caml_bytes.cmj : cc_cmi runtime/caml_bytes.res | runtime/caml_bytes.cm
 o runtime/caml_bytes.cmi : cc runtime/caml_bytes.resi | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
 o runtime/caml_float.cmj : cc_cmi runtime/caml_float.res | runtime/caml_float.cmi runtime/caml_float_extern.cmj
 o runtime/caml_float.cmi : cc runtime/caml_float.resi | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
-o runtime/caml_format.cmj : cc_cmi runtime/caml_format.ml | runtime/caml.cmj runtime/caml_float.cmj runtime/caml_float_extern.cmj runtime/caml_format.cmi runtime/caml_int64.cmj runtime/caml_int64_extern.cmj runtime/caml_nativeint_extern.cmj runtime/caml_string_extern.cmj
+o runtime/caml_format.cmj : cc_cmi runtime/caml_format.ml | runtime/caml_float.cmj runtime/caml_float_extern.cmj runtime/caml_format.cmi runtime/caml_int64.cmj runtime/caml_int64_extern.cmj runtime/caml_nativeint_extern.cmj runtime/caml_string_extern.cmj
 o runtime/caml_format.cmi : cc runtime/caml_format.mli | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
 o runtime/caml_hash.cmj : cc_cmi runtime/caml_hash.res | runtime/caml_hash.cmi runtime/caml_hash_primitive.cmj runtime/caml_nativeint_extern.cmj runtime/js.cmj
 o runtime/caml_hash.cmi : cc runtime/caml_hash.resi | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
@@ -37,7 +37,7 @@ o runtime/caml_md5.cmj : cc_cmi runtime/caml_md5.res | runtime/caml_array_extern
 o runtime/caml_md5.cmi : cc runtime/caml_md5.resi | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
 o runtime/caml_module.cmj : cc_cmi runtime/caml_module.res | runtime/caml_array_extern.cmj runtime/caml_module.cmi runtime/caml_obj.cmj
 o runtime/caml_module.cmi : cc runtime/caml_module.resi | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
-o runtime/caml_obj.cmj : cc_cmi runtime/caml_obj.res | runtime/caml.cmj runtime/caml_array_extern.cmj runtime/caml_obj.cmi runtime/caml_option.cmj runtime/js.cmj
+o runtime/caml_obj.cmj : cc_cmi runtime/caml_obj.res | runtime/caml_array_extern.cmj runtime/caml_obj.cmi runtime/caml_option.cmj runtime/js.cmj
 o runtime/caml_obj.cmi : cc runtime/caml_obj.resi | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
 o runtime/caml_option.cmj : cc_cmi runtime/caml_option.res | runtime/caml_option.cmi runtime/caml_undefined_extern.cmj runtime/js.cmj
 o runtime/caml_option.cmi : cc runtime/caml_option.resi | runtime/bs_stdlib_mini.cmi runtime/caml_undefined_extern.cmj runtime/js.cmi runtime/js.cmj
@@ -54,7 +54,7 @@ o runtime/caml_exceptions.cmi runtime/caml_exceptions.cmj : cc runtime/caml_exce
 o runtime/caml_external_polyfill.cmi runtime/caml_external_polyfill.cmj : cc runtime/caml_external_polyfill.res | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
 o runtime/caml_float_extern.cmi runtime/caml_float_extern.cmj : cc runtime/caml_float_extern.res | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
 o runtime/caml_int64_extern.cmi runtime/caml_int64_extern.cmj : cc runtime/caml_int64_extern.res | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
-o runtime/caml_js_exceptions.cmi runtime/caml_js_exceptions.cmj : cc runtime/caml_js_exceptions.res | runtime/bs_stdlib_mini.cmi runtime/caml_exceptions.cmj runtime/caml_option.cmj runtime/js.cmi runtime/js.cmj
+o runtime/caml_js_exceptions.cmi runtime/caml_js_exceptions.cmj : cc runtime/caml_js_exceptions.res | runtime/bs_stdlib_mini.cmi runtime/caml_exceptions.cmj runtime/js.cmi runtime/js.cmj
 o runtime/caml_nativeint_extern.cmi runtime/caml_nativeint_extern.cmj : cc runtime/caml_nativeint_extern.res | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
 o runtime/caml_string_extern.cmi runtime/caml_string_extern.cmj : cc runtime/caml_string_extern.res | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
 o runtime/caml_undefined_extern.cmi runtime/caml_undefined_extern.cmj : cc runtime/caml_undefined_extern.res | runtime/bs_stdlib_mini.cmi runtime/js.cmi runtime/js.cmj
diff --git a/jscomp/syntax/src/reactjs_jsx_ppx.mli b/jscomp/syntax/src/reactjs_jsx_ppx.mli
index 388202edba..36a8468687 100644
--- a/jscomp/syntax/src/reactjs_jsx_ppx.mli
+++ b/jscomp/syntax/src/reactjs_jsx_ppx.mli
@@ -4,7 +4,7 @@
   facilities; https://whitequark.org/blog/2014/04/16/a-guide-to-extension-
   points-in-ocaml/
   You wouldn't use this file directly; it's used by ReScript's
-  bsconfig.json. Specifically, there's a field called `react-jsx` inside the
+  rescript.json. Specifically, there's a field called `react-jsx` inside the
   field `reason`, which enables this ppx through some internal call in bsb
 *)
 
diff --git a/jscomp/syntax/src/res_multi_printer.ml b/jscomp/syntax/src/res_multi_printer.ml
index 354311ce08..81d14d844c 100644
--- a/jscomp/syntax/src/res_multi_printer.ml
+++ b/jscomp/syntax/src/res_multi_printer.ml
@@ -1,20 +1,26 @@
 let defaultPrintWidth = 100
 
-(* Look at bsconfig.json to set Uncurried or Legacy mode if it contains "uncurried": false *)
-let getUncurriedFromBsconfig ~filename =
-  let rec findBsconfig ~dir =
-    let bsconfig = Filename.concat dir "bsconfig.json" in
-    if Sys.file_exists bsconfig then Some (Res_io.readFile ~filename:bsconfig)
+(* Look at rescript.json (or bsconfig.json) to set Uncurried or Legacy mode if it contains "uncurried": false *)
+let getUncurriedFromConfig ~filename =
+  let rec findConfig ~dir =
+    let config = Filename.concat dir "rescript.json" in
+    if Sys.file_exists config then Some (Res_io.readFile ~filename:config)
     else
-      let parent = Filename.dirname dir in
-      if parent = dir then None else findBsconfig ~dir:parent
+      let config = Filename.concat dir "bsconfig.json" in
+      if Sys.file_exists config then Some (Res_io.readFile ~filename:config)
+      else
+        let parent = Filename.dirname dir in
+        if parent = dir then None else findConfig ~dir:parent
   in
   let rec findFromNodeModules ~dir =
     let parent = Filename.dirname dir in
     if Filename.basename dir = "node_modules" then
-      let bsconfig = Filename.concat parent "bsconfig.json" in
-      if Sys.file_exists bsconfig then Some (Res_io.readFile ~filename:bsconfig)
-      else None
+      let config = Filename.concat parent "rescript.json" in
+      if Sys.file_exists config then Some (Res_io.readFile ~filename:config)
+      else
+        let config = Filename.concat parent "bsconfig.json" in
+        if Sys.file_exists config then Some (Res_io.readFile ~filename:config)
+        else None
     else if parent = dir then None
     else findFromNodeModules ~dir:parent
   in
@@ -23,8 +29,8 @@ let getUncurriedFromBsconfig ~filename =
       Filename.dirname (Filename.concat (Sys.getcwd ()) filename)
     else Filename.dirname filename
   in
-  let bsconfig () =
-    match findBsconfig ~dir with
+  let config () =
+    match findConfig ~dir with
     | None ->
       (* The editor calls format on a temporary file. So bsconfig can't be found.
          This looks outside the node_modules containing the bsc binary *)
@@ -32,11 +38,11 @@ let getUncurriedFromBsconfig ~filename =
       findFromNodeModules ~dir
     | x -> x
   in
-  match bsconfig () with
+  match config () with
   | exception _ -> ()
   | None -> ()
-  | Some bsconfig ->
-    let lines = bsconfig |> String.split_on_char '\n' in
+  | Some config ->
+    let lines = config |> String.split_on_char '\n' in
     let is_legacy_uncurried =
       lines
       |> List.exists (fun line ->
@@ -60,7 +66,7 @@ let getUncurriedFromBsconfig ~filename =
 
 (* print res files to res syntax *)
 let printRes ~ignoreParseErrors ~isInterface ~filename =
-  getUncurriedFromBsconfig ~filename;
+  getUncurriedFromConfig ~filename;
   if isInterface then (
     let parseResult =
       Res_driver.parsingEngine.parseInterface ~forPrinter:true ~filename
diff --git a/rescript b/rescript
index 57b639b660..a667e9a46c 100755
--- a/rescript
+++ b/rescript
@@ -13,7 +13,6 @@ var path = require("path");
 var fs = require("fs");
 var bsc_exe = require("./scripts/bin_path").bsc_exe;
 var rescript_exe = require("./scripts/bin_path").rescript_exe;
-var bsconfig = "bsconfig.json";
 
 var LAST_SUCCESS_BUILD_STAMP = 0;
 var cwd = process.cwd();
@@ -23,12 +22,19 @@ process.env.BSB_PROJECT_ROOT = cwd;
 const isTtyError = process.stderr.isTTY;
 const isTtyStd = process.stdout.isTTY;
 
+var bsConfig = "bsconfig.json"
+var resConfig = "rescript.json";
+var resConfigFile = path.join(cwd, resConfig);
+if (!fs.existsSync(resConfigFile)) {
+  resConfig = bsConfig;
+  resConfigFile = path.join(cwd, bsConfig);
+}
+
 // If the project uses gentype and uses custom file extension
 // via generatedFileExtension, ignore them in watch mode
-var bsConfigFile = path.join(cwd, bsconfig);
 var genTypeFileExtension = ".gen.tsx";
-if (fs.existsSync(bsConfigFile)) {
-  var genTypeConfig = require(bsConfigFile).gentypeconfig;
+if (fs.existsSync(resConfigFile)) {
+  var genTypeConfig = require(resConfigFile).gentypeconfig
   if (genTypeConfig) {
     genTypeFileExtension = genTypeConfig.generatedFileExtension;
   }
@@ -100,7 +106,7 @@ Subcommands:
 Run \`rescript <subcommand> -h\` for subcommand help. Examples:
   rescript build -h
   rescript format -h
-The default \`rescript\` is equivalent to \`rescript build\` subcommand  
+The default \`rescript\` is equivalent to \`rescript build\` subcommand
 `);
 }
 
@@ -321,7 +327,7 @@ Please pick a different one using the \`-ws [host:]port\` flag from bsb.`);
     watchGenerated = watchConfig.generated;
     // close and remove all unused watchers
     watchers = watchers.filter(function (watcher) {
-      if (watcher.dir === bsconfig) {
+      if (watcher.dir === resConfig) {
         return true;
       } else if (watchFiles.indexOf(watcher.dir) < 0) {
         dlog(`${watcher.dir} is no longer watched`);
@@ -511,7 +517,7 @@ Please pick a different one using the \`-ws [host:]port\` flag from bsb.`);
       process.stdin.resume();
     }
 
-    watchers.push({ watcher: fs.watch(bsconfig, onChange), dir: bsconfig });
+    watchers.push({ watcher: fs.watch(resConfig, onChange), dir: resConfig });
   }
 
   logStartCompiling();

From 2d588f29ec084b5dbe6457cf9176f716f1cb2f53 Mon Sep 17 00:00:00 2001
From: Hyeseong Kim <hey@hyeseong.kim>
Date: Mon, 4 Sep 2023 23:49:51 +0900
Subject: [PATCH 2/4] migrate to rescript.json

---
 jscomp/build_tests/case/{bsconfig.json => rescript.json}          | 0
 jscomp/build_tests/case2/{bsconfig.json => rescript.json}         | 0
 jscomp/build_tests/case3/{bsconfig.json => rescript.json}         | 0
 .../build_tests/custom_namespace/{bsconfig.json => rescript.json} | 0
 jscomp/build_tests/cycle/{bsconfig.json => rescript.json}         | 0
 jscomp/build_tests/cycle1/{bsconfig.json => rescript.json}        | 0
 jscomp/build_tests/devonly/{bsconfig.json => rescript.json}       | 0
 .../{bsconfig.json => rescript.json}                              | 0
 jscomp/build_tests/exports/{bsconfig.json => rescript.json}       | 0
 jscomp/build_tests/hyphen2/{bsconfig.json => rescript.json}       | 0
 jscomp/build_tests/in_source/{bsconfig.json => rescript.json}     | 0
 jscomp/build_tests/install/{bsconfig.json => rescript.json}       | 0
 jscomp/build_tests/nested/{bsconfig.json => rescript.json}        | 0
 jscomp/build_tests/nnest/{bsconfig.json => rescript.json}         | 0
 jscomp/build_tests/ns/{bsconfig.json => rescript.json}            | 0
 jscomp/build_tests/post-build/{bsconfig.json => rescript.json}    | 0
 jscomp/build_tests/react_ppx/{bsconfig.json => rescript.json}     | 0
 jscomp/build_tests/rerror/{bsconfig.json => rescript.json}        | 0
 jscomp/build_tests/scoped_ppx/{bsconfig.json => rescript.json}    | 0
 .../a/{bsconfig.json => rescript.json}                            | 0
 .../a/{bsconfig.json => rescript.json}                            | 0
 .../build_tests/uncurried-always/{bsconfig.json => rescript.json} | 0
 .../uncurried_printer/{bsconfig.json => rescript.json}            | 0
 jscomp/build_tests/unicode/{bsconfig.json => rescript.json}       | 0
 jscomp/build_tests/weird_deps/{bsconfig.json => rescript.json}    | 0
 jscomp/build_tests/weird_devdeps/{bsconfig.json => rescript.json} | 0
 jscomp/build_tests/weird_names/{bsconfig.json => rescript.json}   | 0
 .../weird_names_not_found_bug/{bsconfig.json => rescript.json}    | 0
 jscomp/build_tests/x-y/{bsconfig.json => rescript.json}           | 0
 jscomp/build_tests/xpkg/{bsconfig.json => rescript.json}          | 0
 jscomp/build_tests/zerocycle/{bsconfig.json => rescript.json}     | 0
 .../typescript-react-example/{bsconfig.json => rescript.json}     | 0
 32 files changed, 0 insertions(+), 0 deletions(-)
 rename jscomp/build_tests/case/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/case2/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/case3/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/custom_namespace/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/cycle/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/cycle1/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/devonly/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/duplicated_symlinked_packages/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/exports/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/hyphen2/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/in_source/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/install/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/nested/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/nnest/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/ns/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/post-build/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/react_ppx/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/rerror/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/scoped_ppx/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/transitive_pinned_dependency1/a/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/transitive_pinned_dependency2/a/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/uncurried-always/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/uncurried_printer/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/unicode/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/weird_deps/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/weird_devdeps/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/weird_names/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/weird_names_not_found_bug/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/x-y/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/xpkg/{bsconfig.json => rescript.json} (100%)
 rename jscomp/build_tests/zerocycle/{bsconfig.json => rescript.json} (100%)
 rename jscomp/gentype_tests/typescript-react-example/{bsconfig.json => rescript.json} (100%)

diff --git a/jscomp/build_tests/case/bsconfig.json b/jscomp/build_tests/case/rescript.json
similarity index 100%
rename from jscomp/build_tests/case/bsconfig.json
rename to jscomp/build_tests/case/rescript.json
diff --git a/jscomp/build_tests/case2/bsconfig.json b/jscomp/build_tests/case2/rescript.json
similarity index 100%
rename from jscomp/build_tests/case2/bsconfig.json
rename to jscomp/build_tests/case2/rescript.json
diff --git a/jscomp/build_tests/case3/bsconfig.json b/jscomp/build_tests/case3/rescript.json
similarity index 100%
rename from jscomp/build_tests/case3/bsconfig.json
rename to jscomp/build_tests/case3/rescript.json
diff --git a/jscomp/build_tests/custom_namespace/bsconfig.json b/jscomp/build_tests/custom_namespace/rescript.json
similarity index 100%
rename from jscomp/build_tests/custom_namespace/bsconfig.json
rename to jscomp/build_tests/custom_namespace/rescript.json
diff --git a/jscomp/build_tests/cycle/bsconfig.json b/jscomp/build_tests/cycle/rescript.json
similarity index 100%
rename from jscomp/build_tests/cycle/bsconfig.json
rename to jscomp/build_tests/cycle/rescript.json
diff --git a/jscomp/build_tests/cycle1/bsconfig.json b/jscomp/build_tests/cycle1/rescript.json
similarity index 100%
rename from jscomp/build_tests/cycle1/bsconfig.json
rename to jscomp/build_tests/cycle1/rescript.json
diff --git a/jscomp/build_tests/devonly/bsconfig.json b/jscomp/build_tests/devonly/rescript.json
similarity index 100%
rename from jscomp/build_tests/devonly/bsconfig.json
rename to jscomp/build_tests/devonly/rescript.json
diff --git a/jscomp/build_tests/duplicated_symlinked_packages/bsconfig.json b/jscomp/build_tests/duplicated_symlinked_packages/rescript.json
similarity index 100%
rename from jscomp/build_tests/duplicated_symlinked_packages/bsconfig.json
rename to jscomp/build_tests/duplicated_symlinked_packages/rescript.json
diff --git a/jscomp/build_tests/exports/bsconfig.json b/jscomp/build_tests/exports/rescript.json
similarity index 100%
rename from jscomp/build_tests/exports/bsconfig.json
rename to jscomp/build_tests/exports/rescript.json
diff --git a/jscomp/build_tests/hyphen2/bsconfig.json b/jscomp/build_tests/hyphen2/rescript.json
similarity index 100%
rename from jscomp/build_tests/hyphen2/bsconfig.json
rename to jscomp/build_tests/hyphen2/rescript.json
diff --git a/jscomp/build_tests/in_source/bsconfig.json b/jscomp/build_tests/in_source/rescript.json
similarity index 100%
rename from jscomp/build_tests/in_source/bsconfig.json
rename to jscomp/build_tests/in_source/rescript.json
diff --git a/jscomp/build_tests/install/bsconfig.json b/jscomp/build_tests/install/rescript.json
similarity index 100%
rename from jscomp/build_tests/install/bsconfig.json
rename to jscomp/build_tests/install/rescript.json
diff --git a/jscomp/build_tests/nested/bsconfig.json b/jscomp/build_tests/nested/rescript.json
similarity index 100%
rename from jscomp/build_tests/nested/bsconfig.json
rename to jscomp/build_tests/nested/rescript.json
diff --git a/jscomp/build_tests/nnest/bsconfig.json b/jscomp/build_tests/nnest/rescript.json
similarity index 100%
rename from jscomp/build_tests/nnest/bsconfig.json
rename to jscomp/build_tests/nnest/rescript.json
diff --git a/jscomp/build_tests/ns/bsconfig.json b/jscomp/build_tests/ns/rescript.json
similarity index 100%
rename from jscomp/build_tests/ns/bsconfig.json
rename to jscomp/build_tests/ns/rescript.json
diff --git a/jscomp/build_tests/post-build/bsconfig.json b/jscomp/build_tests/post-build/rescript.json
similarity index 100%
rename from jscomp/build_tests/post-build/bsconfig.json
rename to jscomp/build_tests/post-build/rescript.json
diff --git a/jscomp/build_tests/react_ppx/bsconfig.json b/jscomp/build_tests/react_ppx/rescript.json
similarity index 100%
rename from jscomp/build_tests/react_ppx/bsconfig.json
rename to jscomp/build_tests/react_ppx/rescript.json
diff --git a/jscomp/build_tests/rerror/bsconfig.json b/jscomp/build_tests/rerror/rescript.json
similarity index 100%
rename from jscomp/build_tests/rerror/bsconfig.json
rename to jscomp/build_tests/rerror/rescript.json
diff --git a/jscomp/build_tests/scoped_ppx/bsconfig.json b/jscomp/build_tests/scoped_ppx/rescript.json
similarity index 100%
rename from jscomp/build_tests/scoped_ppx/bsconfig.json
rename to jscomp/build_tests/scoped_ppx/rescript.json
diff --git a/jscomp/build_tests/transitive_pinned_dependency1/a/bsconfig.json b/jscomp/build_tests/transitive_pinned_dependency1/a/rescript.json
similarity index 100%
rename from jscomp/build_tests/transitive_pinned_dependency1/a/bsconfig.json
rename to jscomp/build_tests/transitive_pinned_dependency1/a/rescript.json
diff --git a/jscomp/build_tests/transitive_pinned_dependency2/a/bsconfig.json b/jscomp/build_tests/transitive_pinned_dependency2/a/rescript.json
similarity index 100%
rename from jscomp/build_tests/transitive_pinned_dependency2/a/bsconfig.json
rename to jscomp/build_tests/transitive_pinned_dependency2/a/rescript.json
diff --git a/jscomp/build_tests/uncurried-always/bsconfig.json b/jscomp/build_tests/uncurried-always/rescript.json
similarity index 100%
rename from jscomp/build_tests/uncurried-always/bsconfig.json
rename to jscomp/build_tests/uncurried-always/rescript.json
diff --git a/jscomp/build_tests/uncurried_printer/bsconfig.json b/jscomp/build_tests/uncurried_printer/rescript.json
similarity index 100%
rename from jscomp/build_tests/uncurried_printer/bsconfig.json
rename to jscomp/build_tests/uncurried_printer/rescript.json
diff --git a/jscomp/build_tests/unicode/bsconfig.json b/jscomp/build_tests/unicode/rescript.json
similarity index 100%
rename from jscomp/build_tests/unicode/bsconfig.json
rename to jscomp/build_tests/unicode/rescript.json
diff --git a/jscomp/build_tests/weird_deps/bsconfig.json b/jscomp/build_tests/weird_deps/rescript.json
similarity index 100%
rename from jscomp/build_tests/weird_deps/bsconfig.json
rename to jscomp/build_tests/weird_deps/rescript.json
diff --git a/jscomp/build_tests/weird_devdeps/bsconfig.json b/jscomp/build_tests/weird_devdeps/rescript.json
similarity index 100%
rename from jscomp/build_tests/weird_devdeps/bsconfig.json
rename to jscomp/build_tests/weird_devdeps/rescript.json
diff --git a/jscomp/build_tests/weird_names/bsconfig.json b/jscomp/build_tests/weird_names/rescript.json
similarity index 100%
rename from jscomp/build_tests/weird_names/bsconfig.json
rename to jscomp/build_tests/weird_names/rescript.json
diff --git a/jscomp/build_tests/weird_names_not_found_bug/bsconfig.json b/jscomp/build_tests/weird_names_not_found_bug/rescript.json
similarity index 100%
rename from jscomp/build_tests/weird_names_not_found_bug/bsconfig.json
rename to jscomp/build_tests/weird_names_not_found_bug/rescript.json
diff --git a/jscomp/build_tests/x-y/bsconfig.json b/jscomp/build_tests/x-y/rescript.json
similarity index 100%
rename from jscomp/build_tests/x-y/bsconfig.json
rename to jscomp/build_tests/x-y/rescript.json
diff --git a/jscomp/build_tests/xpkg/bsconfig.json b/jscomp/build_tests/xpkg/rescript.json
similarity index 100%
rename from jscomp/build_tests/xpkg/bsconfig.json
rename to jscomp/build_tests/xpkg/rescript.json
diff --git a/jscomp/build_tests/zerocycle/bsconfig.json b/jscomp/build_tests/zerocycle/rescript.json
similarity index 100%
rename from jscomp/build_tests/zerocycle/bsconfig.json
rename to jscomp/build_tests/zerocycle/rescript.json
diff --git a/jscomp/gentype_tests/typescript-react-example/bsconfig.json b/jscomp/gentype_tests/typescript-react-example/rescript.json
similarity index 100%
rename from jscomp/gentype_tests/typescript-react-example/bsconfig.json
rename to jscomp/gentype_tests/typescript-react-example/rescript.json

From 3d75e717d7f09909fe01e56ac3aaaf2a3b379d4e Mon Sep 17 00:00:00 2001
From: Hyeseong Kim <hey@hyeseong.kim>
Date: Mon, 4 Sep 2023 23:50:06 +0900
Subject: [PATCH 3/4] add warning message and its test

---
 jscomp/bsb/bsb_config_load.ml                       |  3 +--
 jscomp/bsb/bsb_config_parse.ml                      | 13 ++++++++-----
 jscomp/bsb/bsb_config_parse.mli                     |  6 +++++-
 jscomp/bsb/bsb_ninja_regen.ml                       |  6 +++++-
 jscomp/build_tests/warn_legacy_config/bsconfig.json |  8 ++++++++
 jscomp/build_tests/warn_legacy_config/input.js      | 10 ++++++++++
 jscomp/build_tests/warn_legacy_config/src/demo.res  |  1 +
 7 files changed, 38 insertions(+), 9 deletions(-)
 create mode 100644 jscomp/build_tests/warn_legacy_config/bsconfig.json
 create mode 100644 jscomp/build_tests/warn_legacy_config/input.js
 create mode 100644 jscomp/build_tests/warn_legacy_config/src/demo.res

diff --git a/jscomp/bsb/bsb_config_load.ml b/jscomp/bsb/bsb_config_load.ml
index e947c920ed..0255663763 100644
--- a/jscomp/bsb/bsb_config_load.ml
+++ b/jscomp/bsb/bsb_config_load.ml
@@ -17,8 +17,7 @@ let load_json ~(per_proj_dir : string) ~(warn_legacy_config : bool)
       | exception _ -> raise e (* forward error from rescript.json *)
   in
   if warn_legacy_config && filename = Literals.bsconfig_json then
-    (* TODO: warn legacy config *)
-    ();
+    print_endline "Warning: bsconfig.json is deprecated. Migrate it to rescript.json\n";
   match Ext_json_parse.parse_json_from_chan abs in_chan
   with
   | v -> close_in in_chan ; (filename, v)
diff --git a/jscomp/bsb/bsb_config_parse.ml b/jscomp/bsb/bsb_config_parse.ml
index 1a6f654ba7..747a2b7e08 100644
--- a/jscomp/bsb/bsb_config_parse.ml
+++ b/jscomp/bsb/bsb_config_parse.ml
@@ -237,7 +237,11 @@ let extract_js_post_build (map : json_map) cwd : string option =
 
 (** ATT: make sure such function is re-entrant.
     With a given [cwd] it works anywhere*)
-let interpret_json ~(package_kind : Bsb_package_kind.t) ~(per_proj_dir : string) ~(warn_legacy_config : bool)
+let interpret_json
+  ~(filename : string)
+  ~(json : Ext_json_types.t)
+  ~(package_kind : Bsb_package_kind.t)
+  ~(per_proj_dir : string)
     : Bsb_config_types.t =
   (* we should not resolve it too early,
       since it is external configuration, no {!Bsb_build_util.convert_and_resolve_path}
@@ -253,10 +257,9 @@ let interpret_json ~(package_kind : Bsb_package_kind.t) ~(per_proj_dir : string)
      1. if [build.ninja] does use [ninja] we need set a variable
      2. we need store it so that we can call ninja correctly
   *)
-  match
-    Bsb_config_load.load_json ~per_proj_dir ~warn_legacy_config
+  match json
   with
-  | filename, Obj { map } -> (
+  | Obj { map } -> (
       let package_name, namespace = extract_package_name_and_namespace map in
       let gentype_config = extract_gentype_config map in
 
@@ -353,7 +356,7 @@ let interpret_json ~(package_kind : Bsb_package_kind.t) ~(per_proj_dir : string)
           }
       | None ->
           Bsb_exception.invalid_spec ("no sources specified in " ^ filename))
-  | filename, _ -> Bsb_exception.invalid_spec (filename ^ " expect a json object {}")
+  | _ -> Bsb_exception.invalid_spec (filename ^ " expect a json object {}")
 
 let deps_from_bsconfig () =
   let cwd = Bsb_global_paths.cwd in
diff --git a/jscomp/bsb/bsb_config_parse.mli b/jscomp/bsb/bsb_config_parse.mli
index 84e18eb1ff..3aedf9891b 100644
--- a/jscomp/bsb/bsb_config_parse.mli
+++ b/jscomp/bsb/bsb_config_parse.mli
@@ -25,4 +25,8 @@
 val deps_from_bsconfig : unit -> Bsb_package_specs.t * Bsb_jsx.t * bool *  Set_string.t
 
 val interpret_json :
-  package_kind:Bsb_package_kind.t -> per_proj_dir:string -> warn_legacy_config:bool -> Bsb_config_types.t
+  filename:string ->
+  json:Ext_json_types.t ->
+  package_kind:Bsb_package_kind.t ->
+  per_proj_dir:string ->
+  Bsb_config_types.t
diff --git a/jscomp/bsb/bsb_ninja_regen.ml b/jscomp/bsb/bsb_ninja_regen.ml
index 009918d8c1..030e98b953 100644
--- a/jscomp/bsb/bsb_ninja_regen.ml
+++ b/jscomp/bsb/bsb_ninja_regen.ml
@@ -38,6 +38,9 @@ let regenerate_ninja ~(package_kind : Bsb_package_kind.t) ~forced ~per_proj_dir
   let check_result =
     Bsb_ninja_check.check ~package_kind ~per_proj_dir ~forced ~file:output_deps
   in
+  let config_filename, config_json =
+    Bsb_config_load.load_json ~per_proj_dir ~warn_legacy_config
+  in
   match check_result with
   | Good -> None (* Fast path, no need regenerate ninja *)
   | Bsb_forced | Bsb_bsc_version_mismatch | Bsb_package_kind_inconsistent
@@ -52,7 +55,8 @@ let regenerate_ninja ~(package_kind : Bsb_package_kind.t) ~forced ~per_proj_dir
         Bsb_clean.clean_self per_proj_dir);
 
       let config : Bsb_config_types.t =
-        Bsb_config_parse.interpret_json ~package_kind ~per_proj_dir ~warn_legacy_config
+        Bsb_config_parse.interpret_json
+          ~filename:config_filename ~json:config_json ~package_kind ~per_proj_dir
       in
       (* create directory, lib/bs, lib/js, lib/es6 etc *)
       Bsb_build_util.mkp lib_bs_dir;
diff --git a/jscomp/build_tests/warn_legacy_config/bsconfig.json b/jscomp/build_tests/warn_legacy_config/bsconfig.json
new file mode 100644
index 0000000000..ff8aa6b4b0
--- /dev/null
+++ b/jscomp/build_tests/warn_legacy_config/bsconfig.json
@@ -0,0 +1,8 @@
+{
+  "name": "warn_legacy_config",
+  "version": "0.1.0",
+  "sources": {
+    "dir": "src",
+    "subdirs": true
+  }
+}
diff --git a/jscomp/build_tests/warn_legacy_config/input.js b/jscomp/build_tests/warn_legacy_config/input.js
new file mode 100644
index 0000000000..ad81e9ec49
--- /dev/null
+++ b/jscomp/build_tests/warn_legacy_config/input.js
@@ -0,0 +1,10 @@
+const { spawnSync } = require("child_process");
+const assert = require("assert");
+const rescript_exe = require("../../../scripts/bin_path").rescript_exe;
+
+const output = spawnSync(rescript_exe, { encoding: "utf8" });
+assert(
+  /^Warning: bsconfig.json is deprecated. Migrate it to rescript.json/.test(
+    output.stdout
+  )
+);
diff --git a/jscomp/build_tests/warn_legacy_config/src/demo.res b/jscomp/build_tests/warn_legacy_config/src/demo.res
new file mode 100644
index 0000000000..8d0b19151f
--- /dev/null
+++ b/jscomp/build_tests/warn_legacy_config/src/demo.res
@@ -0,0 +1 @@
+let () = Js.log("Hello, ReScript")

From 555676fc1f9c69415bb45b21d43674653c38dbd8 Mon Sep 17 00:00:00 2001
From: Hyeseong Kim <hey@hyeseong.kim>
Date: Tue, 3 Oct 2023 23:04:44 +0900
Subject: [PATCH 4/4] add CHANGELOG

---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index bc4ff3c699..5da11628d0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -24,6 +24,7 @@
 - Add builtin abstract types for File and Blob APIs. https://github.com/rescript-lang/rescript-compiler/pull/6383
 - Untagged variants: Support `promise`, RegExes, Dates, File and Blob. https://github.com/rescript-lang/rescript-compiler/pull/6383
 - Support aliased types as payloads to untagged variants. https://github.com/rescript-lang/rescript-compiler/pull/6394
+- Support `rescript.json` configuration file and deprecated `bsconfig.json`. https://github.com/rescript-lang/rescript-compiler/pull/6382
 
 #### :boom: Breaking Change
 - Add smart printer for pipe-chains.  https://github.com/rescript-lang/rescript-compiler/pull/6411 (the formatter will reformat existing code in certain cases)