Remove support for bsconfig.json (#8187)

cknitt · web-flow · commit cba7ed7ec90b · 2026-01-18T18:53:16.000+01:00
* Remove support for bsconfig.json

* Adapt test

* comments

* rename

* doc

* Fix rewatch tests

* rename

* CHANGELOG
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -93,9 +93,6 @@ jobs:
       - name: Install npm packages
         run: yarn install
 
-      - name: Install testrepo deps
-        run: cd rewatch/testrepo && yarn install
-
       - name: Install dependencies (Linux)
         if: runner.os == 'Linux'
         uses: awalsh128/cache-apt-pkgs-action@v1.4.3
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -15,6 +15,7 @@
 #### :boom: Breaking Change
 
 - Remove the legacy build system. Going forward, only the modern build system is supported, and the `rescript-legacy` command is not available anymore. https://github.com/rescript-lang/rescript/pull/8186
+- Remove support for `bsconfig.json`. https://github.com/rescript-lang/rescript/pull/8187
 - `Int.fromString` and `Float.fromString` use stricter number parsing and no longer uses an explicit radix argument, but instead supports parsing hexadecimal, binary and exponential notation.
 - Remove `external-stdlib` configuration option from `rescript.json`. This option was rarely used and is no longer supported.
 - `js-post-build` now passes the correct output file path based on `in-source` configuration: when `in-source: true`, the path next to the source file is passed; when `in-source: false`, the path in the `lib/<module>/` directory is passed. Additionally, stdout and stderr from the post-build command are now logged. https://github.com/rescript-lang/rescript/pull/8190
diff --git a/analysis/reanalyze/src/Paths.ml b/analysis/reanalyze/src/Paths.ml
@@ -1,6 +1,5 @@
 module StringMap = Map_string
 
-let bsconfig = "bsconfig.json"
 let rescriptJson = "rescript.json"
 
 let readFile filename =
@@ -14,8 +13,7 @@ let readFile filename =
 
 let rec findProjectRoot ~dir =
   let rescriptJsonFile = Filename.concat dir rescriptJson in
-  let bsconfigFile = Filename.concat dir bsconfig in
-  if Sys.file_exists rescriptJsonFile || Sys.file_exists bsconfigFile then dir
+  if Sys.file_exists rescriptJsonFile then dir
   else
     let parent = dir |> Filename.dirname in
     if parent = dir then (
@@ -84,10 +82,9 @@ module Config = struct
     | _ -> ()
 
   (* Read the config from rescript.json and apply it to runConfig and suppress and unsuppress *)
-  let processBsconfig () =
+  let processConfig () =
     setProjectRootFromCwd ();
     let rescriptFile = Filename.concat runConfig.projectRoot rescriptJson in
-    let bsconfigFile = Filename.concat runConfig.projectRoot bsconfig in
 
     let processText text =
       match Json.parse text with
@@ -106,10 +103,7 @@ module Config = struct
 
     match readFile rescriptFile with
     | Some text -> processText text
-    | None -> (
-      match readFile bsconfigFile with
-      | Some text -> processText text
-      | None -> ())
+    | None -> ()
 end
 
 (**
diff --git a/analysis/reanalyze/src/Reanalyze.ml b/analysis/reanalyze/src/Reanalyze.ml
@@ -657,7 +657,7 @@ let parse_argv (argv : string array) : string option =
     cmtRootRef := cmtRoot;
     analysisKindSet := true
   and setConfig () =
-    Paths.Config.processBsconfig ();
+    Paths.Config.processConfig ();
     analysisKindSet := true
   and setDCE cmtRoot =
     RunConfig.dce ();
@@ -787,7 +787,7 @@ let parse_argv (argv : string array) : string option =
     - reanalyze can be called from anywhere within the project
 
     Project root detection reuses the same logic as reanalyze config discovery:
-    walk up from a directory until we find rescript.json or bsconfig.json. *)
+    walk up from a directory until we find rescript.json. *)
 let cli () =
   let cmtRoot = parse_argv Sys.argv in
   runAnalysisAndReport ~cmtRoot
diff --git a/analysis/reanalyze/src/ReanalyzeServer.ml b/analysis/reanalyze/src/ReanalyzeServer.ml
@@ -6,7 +6,7 @@
     - reanalyze can be called from anywhere within the project
 
     Project root detection reuses the same logic as reanalyze config discovery:
-    walk up from a directory until we find rescript.json or bsconfig.json. *)
+    walk up from a directory until we find rescript.json. *)
 let default_socket_filename = ".rescript-reanalyze.sock"
 
 let project_root_from_dir (dir : string) : string option =
diff --git a/analysis/src/FindFiles.ml b/analysis/src/FindFiles.ml
@@ -241,7 +241,6 @@ let findDependencyFiles base config =
                (ModuleResolution.resolveNodeModulePath ~startPath:base name)
                (fun path ->
                  let rescriptJsonPath = path /+ "rescript.json" in
-                 let bsconfigJsonPath = path /+ "bsconfig.json" in
 
                  let parseText text =
                    match Json.parse text with
@@ -272,10 +271,7 @@ let findDependencyFiles base config =
 
                  match Files.readFile rescriptJsonPath with
                  | Some text -> parseText text
-                 | None -> (
-                   match Files.readFile bsconfigJsonPath with
-                   | Some text -> parseText text
-                   | None -> None))
+                 | None -> None)
            in
 
            match result with
diff --git a/analysis/src/Packages.ml b/analysis/src/Packages.ml
@@ -34,7 +34,6 @@ let getReScriptVersion () =
 
 let newBsPackage ~rootPath =
   let rescriptJson = Filename.concat rootPath "rescript.json" in
-  let bsconfigJson = Filename.concat rootPath "bsconfig.json" in
 
   let parseRaw raw =
     let libBs =
@@ -192,23 +191,17 @@ let newBsPackage ~rootPath =
 
   match Files.readFile rescriptJson with
   | Some raw -> parseRaw raw
-  | None -> (
+  | None ->
     Log.log ("Unable to read " ^ rescriptJson);
-    match Files.readFile bsconfigJson with
-    | Some raw -> parseRaw raw
-    | None ->
-      Log.log ("Unable to read " ^ bsconfigJson);
-      None)
+    None
 
 let findRoot ~uri packagesByRoot =
   let path = Uri.toPath uri in
   let rec loop path =
     if path = "/" then None
     else if Hashtbl.mem packagesByRoot path then Some (`Root path)
-    else if
-      Files.exists (Filename.concat path "rescript.json")
-      || Files.exists (Filename.concat path "bsconfig.json")
-    then Some (`Bs path)
+    else if Files.exists (Filename.concat path "rescript.json") then
+      Some (`Bs path)
     else
       let parent = Filename.dirname path in
       if parent = path then (* reached root *) None else loop parent
diff --git a/compiler/ext/ext_path.ml b/compiler/ext/ext_path.ml
@@ -268,7 +268,6 @@ let rec find_root_filename ~cwd filenames =
       Ext_fmt.failwithf ~loc:__LOC__ "%s not found from %s" (List.hd filenames)
         cwd
 
-let find_config_dir cwd =
-  find_root_filename ~cwd [Literals.rescript_json; Literals.bsconfig_json]
+let find_config_dir cwd = find_root_filename ~cwd [Literals.rescript_json]
 
 let package_dir = lazy (find_config_dir (Lazy.force cwd))
diff --git a/compiler/ext/literals.ml b/compiler/ext/literals.ml
@@ -72,8 +72,6 @@ let node_modules_length = String.length "node_modules"
 
 let package_json = "package.json"
 
-let bsconfig_json = "bsconfig.json"
-
 let rescript_json = "rescript.json"
 
 (* Name of the library file created for each external dependency. *)
diff --git a/compiler/frontend/ast_config.ml b/compiler/frontend/ast_config.ml
@@ -52,7 +52,7 @@ let process_directives str =
            | None -> Bs_syntaxerr.err item.pstr_loc Expect_string_literal)
          | _ -> ())
 
-let rec iter_on_bs_config_str (x : Parsetree.structure) =
+let rec iter_on_config_str (x : Parsetree.structure) =
   match x with
   | [] -> ()
   | {pstr_desc = Pstr_attribute (({txt = "config"; loc}, payload) as attr)} :: _
@@ -61,14 +61,14 @@ let rec iter_on_bs_config_str (x : Parsetree.structure) =
     Ext_list.iter
       (Ast_payload.ident_or_record_as_config loc payload)
       (Ast_payload.table_dispatch !structural_config_table)
-  | {pstr_desc = Pstr_attribute _} :: rest -> iter_on_bs_config_str rest
+  | {pstr_desc = Pstr_attribute _} :: rest -> iter_on_config_str rest
   | _ :: _ -> ()
 
 let process_str str =
-  iter_on_bs_config_str str;
+  iter_on_config_str str;
   process_directives str
 
-let rec iter_on_bs_config_sig (x : Parsetree.signature) =
+let rec iter_on_config_sig (x : Parsetree.signature) =
   match x with
   | [] -> ()
   | {psig_desc = Psig_attribute (({txt = "config"; loc}, payload) as attr)} :: _
@@ -77,7 +77,7 @@ let rec iter_on_bs_config_sig (x : Parsetree.signature) =
     Ext_list.iter
       (Ast_payload.ident_or_record_as_config loc payload)
       (Ast_payload.table_dispatch !signature_config_table)
-  | {psig_desc = Psig_attribute _} :: rest -> iter_on_bs_config_sig rest
+  | {psig_desc = Psig_attribute _} :: rest -> iter_on_config_sig rest
   | _ :: _ -> ()
 
-let process_sig s = iter_on_bs_config_sig s
+let process_sig s = iter_on_config_sig s
diff --git a/compiler/gentype/GenTypeConfig.ml b/compiler/gentype/GenTypeConfig.ml
@@ -103,13 +103,9 @@ let set_debug ~gtconf =
   | _ -> ()
 
 let compiler_config_file = "rescript.json"
-let legacy_compiler_config_file = "bsconfig.json"
 
 let rec find_project_root ~dir =
-  if
-    Sys.file_exists (Filename.concat dir compiler_config_file)
-    || Sys.file_exists (Filename.concat dir legacy_compiler_config_file)
-  then dir
+  if Sys.file_exists (Filename.concat dir compiler_config_file) then dir
   else
     let parent = dir |> Filename.dirname in
     if parent = dir then (
@@ -238,9 +234,9 @@ let read_config ~get_config_file ~namespace =
   in
   let default_config = {default with project_root; bsb_project_root} in
   match get_config_file ~project_root with
-  | Some bs_config_file -> (
+  | Some config_file -> (
     try
-      let json = bs_config_file |> Ext_json_parse.parse_json_from_file in
+      let json = config_file |> Ext_json_parse.parse_json_from_file in
       match json with
       | Obj {map = bsconf} -> (
         match bsconf |> get_opt "gentypeconfig" with
diff --git a/compiler/gentype/Paths.ml b/compiler/gentype/Paths.ml
@@ -89,10 +89,6 @@ let get_config_file ~project_root =
   let config = concat project_root Config.compiler_config_file in
   match config |> Sys.file_exists with
   | true -> Some config
-  | false -> (
-    let config = concat project_root Config.legacy_compiler_config_file in
-    match config |> Sys.file_exists with
-    | true -> Some config
-    | false -> None)
+  | false -> None
 
 let read_config ~namespace = Config.read_config ~get_config_file ~namespace
diff --git a/rewatch/CompilerConfigurationSpec.md b/rewatch/CompilerConfigurationSpec.md
@@ -1,6 +1,6 @@
 ## ReScript build configuration
 
-This document contains a list of all bsconfig parameters with remarks, and whether they are already implemented in rewatch. It is based on https://rescript-lang.org/docs/manual/latest/build-configuration-schema.
+This document contains a list of all config parameters with remarks, and whether they are already implemented in rewatch. It is based on https://rescript-lang.org/docs/manual/latest/build-configuration-schema.
 
 | Parameter             | JSON type               | Remark                                                      | Implemented? |
 | --------------------- | ----------------------- | ----------------------------------------------------------- | :----------: |
diff --git a/rewatch/MonorepoSupport.md b/rewatch/MonorepoSupport.md
@@ -14,7 +14,7 @@ All statements are derived from:
 
 | Term | Definition |
 |------|------------|
-| **Package** | A folder containing `rescript.json` (or legacy `bsconfig.json`). Usually also has `package.json`. |
+| **Package** | A folder containing `rescript.json`. Usually also has `package.json`. |
 | **Root config** | The `rescript.json` used for global build settings (JSX, output format, etc.). |
 | **Local package** | A package whose canonical path is inside the workspace AND not under any `node_modules` path component. |
 | **Current package** | The package where you ran `rescript build` or `rescript watch`. |
@@ -41,7 +41,7 @@ There are **three effective modes**:
 - The root `rescript.json` should list workspace packages by name in `dependencies`/`dev-dependencies`
 
 ### 3. Monorepo Leaf Package
-- A parent directory contains a `rescript.json` (or `bsconfig.json`)
+- A parent directory contains a `rescript.json`
 - That parent config lists this package's name in its `dependencies` or `dev-dependencies`
 
 ---
diff --git a/rewatch/src/build/packages.rs b/rewatch/src/build/packages.rs
@@ -246,13 +246,7 @@ fn get_source_dirs(source: config::Source, sub_path: Option<PathBuf>) -> AHashSe
 
 pub fn read_config(package_dir: &Path) -> Result<Config> {
     let rescript_json_path = package_dir.join("rescript.json");
-    let bsconfig_json_path = package_dir.join("bsconfig.json");
-
-    if Path::new(&rescript_json_path).exists() {
-        Config::new(&rescript_json_path)
-    } else {
-        Config::new(&bsconfig_json_path)
-    }
+    Config::new(&rescript_json_path)
 }
 
 pub fn read_dependency(
diff --git a/rewatch/src/config.rs b/rewatch/src/config.rs
@@ -75,7 +75,7 @@ impl Source {
     }
 
     /// `to_qualified_without_children` takes a tree like structure of dependencies, coming in from
-    /// `bsconfig`, and turns it into a flat list. The main thing we extract here are the source
+    /// `rescript.json`, and turns it into a flat list. The main thing we extract here are the source
     /// folders, and optional subdirs, where potentially, the subdirs recurse or not.
     pub fn to_qualified_without_children(&self, sub_path: Option<PathBuf>) -> PackageSource {
         match self {
@@ -446,15 +446,15 @@ fn namespace_from_package_name(package_name: &str) -> String {
 }
 
 impl Config {
-    /// Try to convert a bsconfig from a certain path to a bsconfig struct
+    /// Try to convert a config from a certain path to a config struct
     pub fn new(path: &Path) -> Result<Self> {
         let read = fs::read_to_string(path)?;
         let mut config = Config::new_from_json_string(&read)?;
         config.set_path(path.to_path_buf())?;
         Ok(config)
     }
 
-    /// Try to convert a bsconfig from a string to a bsconfig struct
+    /// Try to convert a config from a string to a config struct
     pub fn new_from_json_string(config_str: &str) -> Result<Self> {
         let mut deserializer = serde_json::Deserializer::from_str(config_str);
         let mut tracker = serde_path_to_error::Track::new();
diff --git a/rewatch/src/helpers.rs b/rewatch/src/helpers.rs
@@ -513,7 +513,7 @@ pub fn compute_file_hash(path: &Path) -> Option<blake3::Hash> {
 }
 
 fn has_rescript_config(path: &Path) -> bool {
-    path.join("bsconfig.json").exists() || path.join("rescript.json").exists()
+    path.join("rescript.json").exists()
 }
 
 // traverse up the directory tree until we find a config.json, if not return None
diff --git a/rewatch/tests/suite.sh b/rewatch/tests/suite.sh
@@ -29,7 +29,7 @@ fi
 source ./utils.sh
 
 bold "Yarn install"
-(cd ../testrepo && yarn)
+(cd ../testrepo && yarn && cp node_modules/rescript-nodejs/bsconfig.json node_modules/rescript-nodejs/rescript.json)
 
 bold "Rescript version"
 (cd ../testrepo && ./node_modules/.bin/rescript --version)
diff --git a/tests/build_tests/warn_legacy_config/input.js b/tests/build_tests/warn_legacy_config/input.js
@@ -7,5 +7,5 @@ const { execBuild, execClean } = setup(import.meta.dirname);
 
 const output = await execBuild();
 assert.notEqual(output.status, 0);
-assert.match(output.stderr, /no package\.json or rescript\.json file/i);
+assert.match(output.stderr, /could not read rescript\.json/i);
 await execClean();
diff --git a/tests/tests/src/test_literals.mjs b/tests/tests/src/test_literals.mjs
@@ -5,11 +5,8 @@ let node_modules_length = "node_modules".length;
 
 let node_modules = "node_modules";
 
-let bsconfig_json = "bsconfig.json";
-
 export {
   node_modules,
   node_modules_length,
-  bsconfig_json,
 }
 /* node_modules_length Not a pure module */
diff --git a/tests/tests/src/test_literals.res b/tests/tests/src/test_literals.res
@@ -1,5 +1,3 @@
 /** nodejs */
 let node_modules = "node_modules"
 let node_modules_length = String.length("node_modules")
-
-let bsconfig_json = "bsconfig.json"
diff --git a/tools/bin/main.ml b/tools/bin/main.ml
@@ -88,7 +88,7 @@ let main () =
         (Error
            (Printf.sprintf
               "error: failed to load ReScript project at %s (missing \
-               bsconfig.json/rescript.json?)"
+               rescript.json?)"
               rootPath))
     | Some package ->
       let moduleNames =
