From 6212ef2da436d56e7e1b85cedd1f5a97605cedbd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Manuel=20V=C3=A1zquez=20Acosta?= <mva.led@gmail.com>
Date: Tue, 5 May 2026 17:12:50 +0200
Subject: [PATCH] Fix module packs in unpack expressions

Allow first-class module packs with module type annotations inside unpack expressions,
e.g. `unpack(module(Cleanup): PipelineStep with type state = t)`.

Fixes https://github.com/rescript-lang/tree-sitter-rescript/issues/288
---
 grammar.js              |  1 +
 src/grammar.json        | 21 +++++++++++++++++++++
 src/node-types.json     |  4 ++++
 src/parser.c            |  4 ++--
 test/corpus/modules.txt | 14 ++++++++++++++
 5 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/grammar.js b/grammar.js
index a9b5ec2..a397989 100644
--- a/grammar.js
+++ b/grammar.js
@@ -218,6 +218,7 @@ export default grammar({
             optional($.module_type_annotation),
           ),
           seq($.call_expression, optional($.module_type_annotation)),
+          seq($.module_pack, optional($.module_type_annotation)),
           $.extension_expression,
         ),
         ")",
diff --git a/src/grammar.json b/src/grammar.json
index 3bd9724..4ac3289 100644
--- a/src/grammar.json
+++ b/src/grammar.json
@@ -515,6 +515,27 @@
                 }
               ]
             },
+            {
+              "type": "SEQ",
+              "members": [
+                {
+                  "type": "SYMBOL",
+                  "name": "module_pack"
+                },
+                {
+                  "type": "CHOICE",
+                  "members": [
+                    {
+                      "type": "SYMBOL",
+                      "name": "module_type_annotation"
+                    },
+                    {
+                      "type": "BLANK"
+                    }
+                  ]
+                }
+              ]
+            },
             {
               "type": "SYMBOL",
               "name": "extension_expression"
diff --git a/src/node-types.json b/src/node-types.json
index a999e6b..749094b 100644
--- a/src/node-types.json
+++ b/src/node-types.json
@@ -2848,6 +2848,10 @@
           "type": "member_expression",
           "named": true
         },
+        {
+          "type": "module_pack",
+          "named": true
+        },
         {
           "type": "module_type_annotation",
           "named": true
diff --git a/src/parser.c b/src/parser.c
index 494a5c3..a988f79 100644
--- a/src/parser.c
+++ b/src/parser.c
@@ -94034,7 +94034,7 @@ static const uint16_t ts_parse_table[LARGE_STATE_COUNT][SYMBOL_COUNT] = {
     [sym_try_expression] = STATE(1424),
     [sym_call_expression] = STATE(3465),
     [sym_pipe_expression] = STATE(1424),
-    [sym_module_pack] = STATE(1424),
+    [sym_module_pack] = STATE(3465),
     [sym__definition_signature] = STATE(4828),
     [sym_formal_parameters] = STATE(4448),
     [sym__jsx_element] = STATE(1424),
@@ -94424,7 +94424,7 @@ static const uint16_t ts_parse_table[LARGE_STATE_COUNT][SYMBOL_COUNT] = {
     [sym_try_expression] = STATE(1424),
     [sym_call_expression] = STATE(3483),
     [sym_pipe_expression] = STATE(1424),
-    [sym_module_pack] = STATE(1424),
+    [sym_module_pack] = STATE(3483),
     [sym__definition_signature] = STATE(4828),
     [sym_formal_parameters] = STATE(4448),
     [sym__jsx_element] = STATE(1424),
diff --git a/test/corpus/modules.txt b/test/corpus/modules.txt
index ed7cb02..eec9f53 100644
--- a/test/corpus/modules.txt
+++ b/test/corpus/modules.txt
@@ -245,6 +245,8 @@ module(
 )
 module(SomeFunctor(unpack(x)))
 
+module M = unpack(module(Cleanup): PipelineStep with type state = t)
+
 module T = unpack(foo: T)
 
 module S = unpack(foo: T with type t = a)
@@ -288,6 +290,18 @@ module T3 = unpack(make(): T with type t = int)
         (arguments
           (module_unpack
             (value_identifier))))))
+  (module_declaration
+    (module_binding
+      (module_identifier)
+      (module_unpack
+        (module_pack
+          (module_identifier))
+        (module_type_annotation
+          (module_type_constraint
+            (module_identifier)
+            (constrain_type
+              (type_identifier)
+              (type_identifier)))))))
   (module_declaration
     (module_binding
       (module_identifier)