Fix finding the standard library for pnpm

.github/workflows/ci.yml

@@ -522,7 +522,7 @@ jobs:
           git commit -m "Update API docs for ${{ github.ref_name }}"
           git push
 
-  test-integration:
+  test-installation-npm:
     needs:
       - pkg-pr-new
     strategy:
@@ -573,6 +573,86 @@ jobs:
         shell: bash
         working-directory: ${{ steps.tmp-dir.outputs.path }}
 
+  test-installation-pnpm:
+    needs:
+      - pkg-pr-new
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - os: macos-13
+          - os: macos-14
+          - os: ubuntu-24.04
+          - os: ubuntu-24.04-arm
+          - os: windows-latest
+    runs-on: ${{ matrix.os }}
+    env:
+      RUST_BACKTRACE: "1"
+    steps:
+      - name: Install pnpm
+        uses: pnpm/action-setup@v4
+        with:
+          version: 10
+
+      - name: Use Node.js
+        uses: actions/setup-node@v4
+        with:
+          # Run integration tests with the oldest supported node version.
+          node-version: 20
+
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Make test directory
+        id: tmp-dir
+        shell: bash
+        run: |
+          if [[ "$RUNNER_OS" == "Windows" ]]; then
+            dir=$(powershell -Command "[System.IO.Path]::GetTempPath() + [System.Guid]::NewGuid().ToString()" | tr -d '\r')
+            mkdir -p "$dir"
+          else
+            dir=$(mktemp -d)
+          fi
+          echo "path=$dir" >> "$GITHUB_OUTPUT"
+          cp -r tests/package_tests/installation_test/* "$dir"
+
+      - name: Install ReScript package
+        run: |
+          COMMIT_SHA="${{ github.event.pull_request.head.sha || github.sha }}"
+          pnpm i "https://pkg.pr.new/rescript-lang/rescript@${COMMIT_SHA::7}"
+        shell: bash
+        working-directory: ${{ steps.tmp-dir.outputs.path }}
+
+      - name: Test installation
+        run: pnpm rescript -h && pnpm rescript legacy build && cat src/Test.res.js
+        shell: bash
+        working-directory: ${{ steps.tmp-dir.outputs.path }}
+
+  test-integration-rewatch:
+    needs:
+      - pkg-pr-new
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - os: macos-13
+          - os: macos-14
+          - os: ubuntu-24.04
+          - os: ubuntu-24.04-arm
+          - os: windows-latest
+    runs-on: ${{ matrix.os }}
+    env:
+      RUST_BACKTRACE: "1"
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Use Node.js
+        uses: actions/setup-node@v4
+        with:
+          # Run integration tests with the oldest supported node version.
+          node-version: 20
+
       - name: Install ReScript package in rewatch/testrepo
         run: |
           COMMIT_SHA="${{ github.event.pull_request.head.sha || github.sha }}"
@@ -586,7 +666,9 @@ jobs:
 
   publish:
     needs:
-      - test-integration
+      - test-installation-npm
+      - test-installation-pnpm
+      - test-integration-rewatch
     if: startsWith(github.ref, 'refs/tags/v')
     runs-on: ubuntu-24.04-arm
     steps:

CHANGELOG.md

@@ -51,6 +51,7 @@
 - Rewatch: fix non-unicode stderr. https://github.com/rescript-lang/rescript/pull/7613
 - Fix rewatch considering warning configs of non-local dependencies. https://github.com/rescript-lang/rescript/pull/7614
 - Rewatch: fix panic if package.json name different from module name. https://github.com/rescript-lang/rescript/pull/7616
+- Fix finding the standard library for pnpm. https://github.com/rescript-lang/rescript/pull/7615
 
 #### :nail_care: Polish
 

compiler/ext/config.ml

@@ -1,23 +1,35 @@
 let version = "4.06.1+BS"
 
-(* FIXME: Unreliable resolution *)
+(* This resolves the location of the standard library starting from the location of bsc.exe,
+  handling different supported package layouts. *)
 let standard_library =
-  let ( // ) = Filename.concat in
-  let exe_path = Sys.executable_name in
-  if Ext_string.contain_substring exe_path ("node_modules" // "@rescript") then
-    (* node_modules/@rescript/{platform}/bin *)
-    Filename.dirname exe_path // Filename.parent_dir_name
-    // Filename.parent_dir_name // Filename.parent_dir_name // "rescript"
-    // "lib" // "ocaml"
-  else if Ext_string.contain_substring exe_path ("node_modules" // "rescript")
-  then
-    (* node_modules/rescript/{platform} *)
-    Filename.dirname exe_path // Filename.parent_dir_name // "lib" // "ocaml"
-  else
-    (* git repo: rescript/packages/@rescript/{platform}/bin *)
-    Filename.dirname exe_path // Filename.parent_dir_name
-    // Filename.parent_dir_name // Filename.parent_dir_name
-    // Filename.parent_dir_name // "lib" // "ocaml"
+  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"]
+  | _ -> ""
 
 let standard_library_default = standard_library