Resolve @rescript/runtime

CHANGELOG.md

@@ -41,6 +41,7 @@
 
 - Playground: Add config options for experimental features and jsx preserve mode. https://github.com/rescript-lang/rescript/pull/7865
 - Clean up tests. https://github.com/rescript-lang/rescript/pull/7861 https://github.com/rescript-lang/rescript/pull/7871
+- Add `-runtime-path` flag to `bsc` (and `bsb`), we are detecting the location of `@rescript/runtime` in `cli/rescript.js` based on runtime module resolution. https://github.com/rescript-lang/rescript/pull/7858
 
 # 12.0.0-beta.10
 

analysis/src/ModuleResolution.ml

@@ -3,7 +3,7 @@ let ( /+ ) = Filename.concat
 let rec resolveNodeModulePath ~startPath name =
   if name = "@rescript/runtime" then
     (* Hack: we need a reliable way to resolve modules in monorepos. *)
-    Some Config.runtime_module_path
+    Some !Runtime_package.path
   else
     let scope = Filename.dirname name in
     let name = Filename.basename name in

biome.json

@@ -75,7 +75,9 @@
       "*.d.ts",
       "*.exe",
       "package.json",
-      "packages/artifacts.json"
+      "packages/artifacts.json",
+      ".mypy_cache/**",
+      ".history/**"
     ]
   }
 }

cli/bsc.js

@@ -5,8 +5,12 @@
 import { execFileSync } from "node:child_process";
 
 import { bsc_exe } from "./common/bins.js";
+import { runtimePath } from "./common/runtime.js";
 
 const delegate_args = process.argv.slice(2);
+if (!delegate_args.includes("-runtime-path")) {
+  delegate_args.push("-runtime-path", runtimePath);
+}
 
 try {
   execFileSync(bsc_exe, delegate_args, { stdio: "inherit" });

cli/common/bsb.js

@@ -6,6 +6,7 @@ import { createServer } from "node:http";
 import * as os from "node:os";
 import * as path from "node:path";
 
+import { runtimePath } from "../common/runtime.js";
 import { rescript_legacy_exe } from "./bins.js";
 import { WebSocket } from "./minisocket.js";
 
@@ -49,6 +50,11 @@ function acquireBuild(args, options) {
   if (ownerProcess) {
     return null;
   }
+
+  if (args[0] === "build" && !args.includes("-runtime-path")) {
+    args.push("-runtime-path", runtimePath);
+  }
+
   try {
     ownerProcess = child_process.spawn(rescript_legacy_exe, args, {
       stdio: "inherit",

cli/common/runtime.js

@@ -0,0 +1,78 @@
+import { promises as fs } from "node:fs";
+import { createRequire } from "node:module";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+
+/**
+ * 🚨 Why this hack exists:
+ *
+ * Unlike Node or Bun, Deno's `import.meta.resolve("npm:...")` does NOT return a
+ * filesystem path. It just echoes back the npm: specifier. The actual package
+ * tarballs are unpacked into `node_modules/.deno/...` when you use
+ * `--node-modules-dir`, and normal `node_modules/<pkg>` symlinks only exist for
+ * *direct* dependencies. Transitive deps (like @rescript/runtime in our case)
+ * only live inside `.deno/` and have no symlink.
+ *
+ * Because Deno doesn't expose an API for “give me the absolute path of this npm
+ * package”, the only way to emulate Node’s/Bun’s `require.resolve` behaviour is
+ * to glob inside `.deno/` and reconstruct the path manually.
+ *
+ * TL;DR: This function exists to compensate for the fact that Deno deliberately hides its
+ * npm cache layout. If you want a stable on‑disk path for a package in Deno,
+ * you have to spelunk `node_modules/.deno/>pkg@version>/node_modules/<pkg>`.
+ *
+ * If Deno ever ships a proper API for this, replace this hack immediately.
+ */
+async function resolvePackageInDeno(pkgName) {
+  const base = path.resolve("node_modules/.deno");
+  const pkgId = pkgName.startsWith("@") ? pkgName.replace("/", "+") : pkgName;
+
+  const { expandGlob } = await import("https://deno.land/std/fs/mod.ts");
+  for await (const entry of expandGlob(
+    path.join(base, `${pkgId}@*/node_modules/${pkgName}`),
+  )) {
+    if (entry.isDirectory) {
+      return await fs.realpath(entry.path);
+    }
+  }
+
+  throw new Error(
+    `Could not resolve ${pkgName} in Deno. Did you enable --node-modules-dir?`,
+  );
+}
+
+async function resolvePackageRoot(pkgName) {
+  const specifier =
+    typeof globalThis.Deno !== "undefined"
+      ? `npm:${pkgName}/package.json`
+      : `${pkgName}/package.json`;
+
+  if (typeof import.meta.resolve === "function") {
+    const url = import.meta.resolve(specifier);
+
+    if (url.startsWith("file://")) {
+      // Node & Bun: real local file
+      const abs = path.dirname(fileURLToPath(url));
+      return await fs.realpath(abs);
+    }
+
+    if (typeof globalThis.Deno !== "undefined") {
+      return await resolvePackageInDeno(pkgName);
+    }
+
+    throw new Error(
+      `Could not resolve ${pkgName} (no physical path available)`,
+    );
+  }
+
+  // Node fallback
+  const require = createRequire(import.meta.url);
+  try {
+    const abs = path.dirname(require.resolve(`${pkgName}/package.json`));
+    return await fs.realpath(abs);
+  } catch {
+    throw new Error(`Could not resolve ${pkgName} in Node runtime`);
+  }
+}
+
+export const runtimePath = await resolvePackageRoot("@rescript/runtime");

cli/rescript.js

@@ -4,6 +4,7 @@
 
 import * as child_process from "node:child_process";
 import { rescript_exe } from "./common/bins.js";
+import { runtimePath } from "./common/runtime.js";
 
 const args = process.argv.slice(2);
 
@@ -18,6 +19,7 @@ const args = process.argv.slice(2);
 //   exit the parent with the correct status only after the child has exited.
 const child = child_process.spawn(rescript_exe, args, {
   stdio: "inherit",
+  env: { ...process.env, RESCRIPT_RUNTIME: runtimePath },
 });
 
 // Map POSIX signal names to conventional exit status numbers so we can

compiler/bsb/bsb_arg.ml

@@ -48,8 +48,11 @@ let usage_b (buf : Ext_buffer.t) ~usage (speclist : t) =
   else (
     buf +> "\nOptions:\n";
     let max_col = ref 0 in
-    Ext_array.iter speclist (fun (key, _, _) ->
-        if String.length key > !max_col then max_col := String.length key);
+    Ext_array.iter speclist (fun (key, _, doc) ->
+        if
+          (not (Ext_string.starts_with doc "*internal*"))
+          && String.length key > !max_col
+        then max_col := String.length key);
     Ext_array.iter speclist (fun (key, _, doc) ->
         if not (Ext_string.starts_with doc "*internal*") then (
           buf +> "  ";

compiler/bsb/bsb_exception.ml

@@ -47,7 +47,7 @@ let print (fmt : Format.formatter) (x : error) =
       modname
   | Package_not_found name ->
     let name = Bsb_pkg_types.to_string name in
-    if Ext_string.equal name Bs_version.package_name then
+    if Ext_string.equal name Runtime_package.name then
       Format.fprintf fmt
         "File \"rescript.json\", line 1\n\
          @{<error>Error:@} package @{<error>%s@} is not found\n\

compiler/bsb/bsb_ninja_rule.ml

@@ -107,6 +107,7 @@ let make_custom_rules ~(gentype_config : Bsb_config_types.gentype_config)
       string =
     Ext_buffer.clear buf;
     Ext_buffer.add_string buf bsc;
+    Ext_buffer.add_string buf (" -runtime-path " ^ !Runtime_package.path);
     Ext_buffer.add_string buf ns_flag;
     if read_cmi = `yes then Ext_buffer.add_string buf " -bs-read-cmi";
     (* The include order matters below *)
@@ -139,6 +140,7 @@ let make_custom_rules ~(gentype_config : Bsb_config_types.gentype_config)
   let mk_ast =
     Ext_buffer.clear buf;
     Ext_buffer.add_string buf bsc;
+    Ext_buffer.add_string buf (" -runtime-path " ^ !Runtime_package.path);
     Ext_buffer.add_char_string buf ' ' warnings;
     (match ppx_files with
     | [] -> ()

compiler/bsb_exe/rescript_main.ml

@@ -110,6 +110,8 @@ let install_target () =
   let eid = Bsb_unix.run_command_execv install_command in
   if eid <> 0 then Bsb_unix.command_fatal_error install_command eid
 
+let setup_runtime_path path = Runtime_package.path := path
+
 let build_subcommand ~start argv argv_len =
   let i = Ext_array.rfind_with_index argv Ext_string.equal separator in
 
@@ -141,6 +143,9 @@ let build_subcommand ~start argv argv_len =
         unit_set_spec no_deps_mode,
         "*internal* Needed for watcher to build without dependencies on file \
          change" );
+      ( "-runtime-path",
+        string_call setup_runtime_path,
+        "*internal* Set the path of the runtime package (@rescript/runtime)" );
       ( "-warn-error",
         string_call (fun s -> warning_as_error := Some s),
         "Warning numbers and whether to turn them into errors, e.g., \

compiler/bsc/rescript_compiler_main.ml

@@ -50,6 +50,8 @@ let set_abs_input_name sourcefile =
   sourcefile
 let setup_outcome_printer () = Lazy.force Res_outcome_printer.setup
 
+let setup_runtime_path path = Runtime_package.path := path
+
 let process_file sourcefile ?kind ppf =
   (* This is a better default then "", it will be changed later
      The {!Location.input_name} relies on that we write the binary ast
@@ -394,6 +396,9 @@ let command_line_flags : (string * Bsc_args.spec * string) array =
     ( "-unsafe",
       set Clflags.fast,
       "*internal* Do not compile bounds checking on array and string access" );
+    ( "-runtime-path",
+      string_call setup_runtime_path,
+      "*internal* Set the path of the runtime package (@rescript/runtime)" );
     ( "-warn-help",
       unit_call Warnings.help_warnings,
       "Show description of warning numbers" );

compiler/common/bs_version.ml

@@ -23,4 +23,3 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *)
 let version = "12.0.0-beta.11"
 let header = "// Generated by ReScript, PLEASE EDIT WITH CARE"
-let package_name = "@rescript/runtime"

compiler/common/bs_version.mli

@@ -25,5 +25,3 @@
 val version : string
 
 val header : string
-
-val package_name : string

compiler/core/js_name_of_module_id.ml

@@ -95,7 +95,7 @@ let get_runtime_module_path
           (*Invariant: the package path to rescript, it is used to 
             calculate relative js path
           *)
-          (Config.runtime_module_path // dep_path // js_file)
+          (!Runtime_package.path // dep_path // js_file)
 
 (* [output_dir] is decided by the command line argument *)
 let string_of_module_id 

compiler/core/js_packages_info.ml

@@ -48,7 +48,7 @@ let runtime_dir_of_module_system (ms : module_system) =
   | Esmodule | Es6_global -> "es6"
 
 let runtime_package_path (ms : module_system) js_file =
-  Bs_version.package_name // "lib" // runtime_dir_of_module_system ms // js_file
+  Runtime_package.name // "lib" // runtime_dir_of_module_system ms // js_file
 
 type t = {name: package_name; module_systems: package_info list}
 
@@ -163,7 +163,7 @@ let query_package_infos ({name; module_systems} : t)
     with
     | Some k ->
       let rel_path = k.path in
-      let pkg_rel_path = Bs_version.package_name // rel_path in
+      let pkg_rel_path = Runtime_package.name // rel_path in
       Package_found {rel_path; pkg_rel_path; suffix = k.suffix}
     | None -> Package_not_found)
 

compiler/core/res_compmisc.ml

@@ -23,13 +23,15 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. *)
 
 let init_path () =
-  let dirs = !Clflags.include_dirs in
-  let exp_dirs =
-    List.map (Misc.expand_directory Config.standard_library) dirs
+  let stdlib_dir =
+    let ( // ) = Filename.concat in
+    !Runtime_package.path // "lib" // "ocaml"
   in
+  let dirs = !Clflags.include_dirs in
+  let exp_dirs = List.map (Misc.expand_directory stdlib_dir) dirs in
   Config.load_path :=
     if !Js_config.no_stdlib then exp_dirs
-    else List.rev_append exp_dirs [Config.standard_library];
+    else List.rev_append exp_dirs [stdlib_dir];
   Env.reset_cache ()
 
 (* Return the initial environment in which compilation proceeds. *)

compiler/ext/config.ml

@@ -1,40 +1,3 @@
-(* This resolves the location of the standard library starting from the location of bsc.exe
-   (@rescript/{platform}/bin/bsc.exe), handling different supported package layouts. *)
-let runtime_module_path =
-  let build_path rest path =
-    String.concat Filename.dir_sep (List.rev_append rest path)
-  in
-  match
-    Sys.executable_name |> Filename.dirname
-    |> String.split_on_char Filename.dir_sep.[0]
-    |> List.rev
-  with
-  (* 1. Packages installed via pnpm
-     - bin:     node_modules/.pnpm/@[email protected]/node_modules/@rescript/darwin-arm64/bin
-     - runtime: node_modules/.pnpm/node_modules/@rescript/runtime (symlink)
-  *)
-  | "bin" :: _platform :: "@rescript" :: "node_modules" :: _package :: ".pnpm"
-    :: "node_modules" :: rest ->
-    build_path rest
-      ["node_modules"; ".pnpm"; "node_modules"; "@rescript"; "runtime"]
-  (* 2. Packages installed via npm
-     - bin:     node_modules/@rescript/{platform}/bin
-     - runtime: node_modules/@rescript/runtime
-  *)
-  | "bin" :: _platform :: "@rescript" :: "node_modules" :: rest ->
-    build_path rest ["node_modules"; "@rescript"; "runtime"]
-  (* 3. Several other cases that can occur in local development, e.g.
-     - bin:     <repo>/packages/@rescript/{platform}/bin, <repo>/_build/install/default/bin
-     - runtime: <repo>/packages/@rescript/runtime
-  *)
-  | _ :: _ :: _ :: _ :: rest ->
-    build_path rest ["packages"; "@rescript"; "runtime"]
-  | _ -> ""
-
-let standard_library =
-  let ( // ) = Filename.concat in
-  runtime_module_path // "lib" // "ocaml"
-
 let cmi_magic_number = "Caml1999I022"
 
 and ast_impl_magic_number = "Caml1999M022"

compiler/ext/config.mli

@@ -15,12 +15,6 @@
 
 (* System configuration *)
 
-(* The directory containing the runtime module (@rescript/runtime) *)
-val runtime_module_path : string
-
-(* The directory containing the runtime artifacts (@rescript/runtime/lib/ocaml) *)
-val standard_library : string
-
 (* Directories in the search path for .cmi and .cmo files *)
 val load_path : string list ref
 

compiler/ext/runtime_package.ml

@@ -0,0 +1,29 @@
+let name = "@rescript/runtime"
+
+(* Simple default approach to find the runtime package path. This will not work with all package managers/layouts. *)
+let default_path =
+  let build_path rest path =
+    String.concat Filename.dir_sep (List.rev_append rest path)
+  in
+  match
+    Sys.executable_name |> Filename.dirname
+    |> String.split_on_char Filename.dir_sep.[0]
+    |> List.rev
+  with
+  (* 1. Packages installed via npm
+     - bin:     node_modules/@rescript/{platform}/bin
+     - runtime: node_modules/@rescript/runtime
+  *)
+  | "bin" :: _platform :: "@rescript" :: "node_modules" :: rest ->
+    build_path rest ["node_modules"; "@rescript"; "runtime"]
+  (* 2. Several other cases that can occur in local development, e.g.
+     - bin:     <repo>/packages/@rescript/{platform}/bin, <repo>/_build/install/default/bin
+     - runtime: <repo>/packages/@rescript/runtime
+  *)
+  | _ :: _ :: _ :: _ :: rest ->
+    build_path rest ["packages"; "@rescript"; "runtime"]
+  | _ -> ""
+
+(* To support pnpm and other package managers/layouts, we determine the path on the JS side and pass it in
+via -runtime-path to override the default. *)
+let path = ref default_path

compiler/ext/runtime_package.mli

@@ -0,0 +1,2 @@
+val name : string
+val path : string ref

packages/artifacts.json

@@ -12,6 +12,7 @@
     "cli/common/bins.js",
     "cli/common/bsb.js",
     "cli/common/minisocket.js",
+    "cli/common/runtime.js",
     "cli/rescript-legacy.js",
     "cli/rescript-legacy/dump.js",
     "cli/rescript-legacy/format.js",

rewatch/src/build.rs

@@ -99,7 +99,7 @@ pub fn get_compiler_args(rescript_file_path: &Path) -> Result<String> {
         &None,
         is_type_dev,
         true,
-    );
+    )?;
 
     let result = serde_json::to_string_pretty(&CompilerArgs {
         compiler_args,