Reliably determine standard lib dir

# Conflicts:
#	cli/rescript.js
#	rewatch/tests/suite-ci.sh

Author: cknitt

cli/bsc.js

@@ -5,11 +5,15 @@
 import { execFileSync } from "node:child_process";
 
 import { bsc_exe } from "./common/bins.js";
+import { stdlibDir } from "./common/stdlib.js";
 
 const delegate_args = process.argv.slice(2);
 
 try {
-  execFileSync(bsc_exe, delegate_args, { stdio: "inherit" });
+  execFileSync(bsc_exe, delegate_args, {
+    stdio: "inherit",
+    env: { ...process.env, RESCRIPT_STDLIB: stdlibDir },
+  });
 } catch (e) {
   if (e.code === "ENOENT") {
     console.error(String(e));

cli/common/stdlib.js

@@ -0,0 +1,10 @@
+// @ts-check
+import * as path from "node:path";
+import { fileURLToPath } from "node:url";
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+
+const rescriptDir = path.dirname(path.dirname(__dirname));
+
+export const stdlibDir = path.join(rescriptDir, "lib", "ocaml");

cli/rescript-legacy/bsb.js

@@ -8,6 +8,7 @@ import * as path from "node:path";
 import { WebSocket } from "#lib/minisocket";
 
 import { rescript_legacy_exe } from "../common/bins.js";
+import { stdlibDir } from "../common/stdlib.js";
 
 const cwd = process.cwd();
 const lockFileName = path.join(cwd, ".bsb.lock");
@@ -52,6 +53,7 @@ function acquireBuild(args, options) {
   try {
     ownerProcess = child_process.spawn(rescript_legacy_exe, args, {
       stdio: "inherit",
+      env: { ...process.env, RESCRIPT_STDLIB: stdlibDir },
       ...options,
     });
     fs.writeFileSync(lockFileName, ownerProcess.pid.toString(), {

cli/rescript-tools.js

@@ -5,7 +5,11 @@
 import * as child_process from "node:child_process";
 
 import { rescript_tools_exe } from "./common/bins.js";
+import { stdlibDir } from "./common/stdlib.js";
 
 const args = process.argv.slice(2);
 
-child_process.spawnSync(rescript_tools_exe, args, { stdio: "inherit" });
+child_process.spawnSync(rescript_tools_exe, args, {
+  stdio: "inherit",
+  env: { ...process.env, RESCRIPT_STDLIB: stdlibDir },
+});

cli/rescript.js

@@ -4,12 +4,14 @@
 
 import * as child_process from "node:child_process";
 import { rescript_exe } from "./common/bins.js";
+import { stdlibDir } from "./common/stdlib.js";
 
 const args = process.argv.slice(2);
 
 try {
   child_process.execFileSync(rescript_exe, args, {
     stdio: "inherit",
+    env: { ...process.env, RESCRIPT_STDLIB: stdlibDir },
   });
 } catch (err) {
   if (err.status !== undefined) {

compiler/ext/config.ml

@@ -1,33 +1,10 @@
-(* This resolves the location of the standard library starting from the location of bsc.exe,
-  handling different supported package layouts. *)
+(* To determine the standard library path in a reliable way that works with all package managers /
+   package directory layouts, we need to do it on the JS side, see cli/common/stdlib.js.
+   We pass the directory to the compiler exe via the environment variable RESCRIPT_STDLIB. *)
 let standard_library =
-  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/@rescript+darwin-arm64@12.0.0-alpha.13/node_modules/@rescript/darwin-arm64/bin
-     - stdlib: node_modules/rescript/lib/ocaml (symlink)
-  *)
-  | "bin" :: _platform :: "@rescript" :: "node_modules" :: _package :: ".pnpm"
-    :: "node_modules" :: rest ->
-    build_path rest ["node_modules"; "rescript"; "lib"; "ocaml"]
-  (* 2. Packages installed via npm
-     - bin:    node_modules/@rescript/{platform}/bin
-     - stdlib: node_modules/rescript/lib/ocaml
-  *)
-  | "bin" :: _platform :: "@rescript" :: "node_modules" :: rest ->
-    build_path rest ["node_modules"; "rescript"; "lib"; "ocaml"]
-  (* 3. Several other cases that can occur in local development, e.g.
-     - bin:    <repo>/packages/@rescript/{platform}/bin, <repo>/_build/install/default/bin
-     - stdlib: <repo>/lib/ocaml
-  *)
-  | _ :: _ :: _ :: _ :: rest -> build_path rest ["lib"; "ocaml"]
-  | _ -> ""
+  match Sys.getenv_opt "RESCRIPT_STDLIB" with
+  | Some path -> path
+  | None -> ""
 
 let cmi_magic_number = "Caml1999I022"
 

lib_dev/process.js

@@ -2,6 +2,7 @@ import * as child_process from "node:child_process";
 import * as fs from "node:fs/promises";
 import * as path from "node:path";
 import { bsc_exe, rescript_legacy_exe } from "#cli/bins";
+import { stdlibDir } from "#cli/stdlib";
 
 /**
  * @typedef {{
@@ -54,6 +55,7 @@ export function setup(cwd = process.cwd()) {
       cwd,
       shell: process.platform === "win32",
       stdio: ["ignore", "pipe", "pipe"],
+      env: { ...process.env, RESCRIPT_STDLIB: stdlibDir },
       ...options,
     });
 

rewatch/tests/suite-ci.sh

@@ -15,12 +15,10 @@ fi
 
 export REWATCH_EXECUTABLE
 export RESCRIPT_BSC_EXE
+export RESCRIPT_STDLIB=$(realpath ../../lib/ocaml)
 
 source ./utils.sh
 
-bold "Rescript version"
-(cd ../testrepo && ./node_modules/.bin/rescript -v)
-
 # we need to reset the yarn.lock and package.json to the original state
 # so there is not diff in git. The CI will install new ReScript package
 bold "Reset package.json and yarn.lock"