From 5fe6c6e4554223a38e3a9bb5f1e43c6374228ea3 Mon Sep 17 00:00:00 2001
From: ksss <co000ri@gmail.com>
Date: Wed, 1 Nov 2023 23:09:34 +0900
Subject: [PATCH] Fix error when MASGN

Fix https://github.com/ruby/rbs/issues/1330
---
 lib/rbs/prototype/rbi.rb       |  2 +-
 test/rbs/rbi_prototype_test.rb | 21 +++++++++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/lib/rbs/prototype/rbi.rb b/lib/rbs/prototype/rbi.rb
index 41f39f6dd..c0a10ffc1 100644
--- a/lib/rbs/prototype/rbi.rb
+++ b/lib/rbs/prototype/rbi.rb
@@ -246,7 +246,7 @@ def process(node, outer: [], comments:)
               end
             end
             value_node = node.children.last
-            type = if value_node.type == :CALL && value_node.children[1] == :let
+            type = if value_node && value_node.type == :CALL && value_node.children[1] == :let
                      type_node = each_arg(value_node.children[2]).to_a[1]
                      type_of type_node, variables: current_module&.type_params || []
                    else
diff --git a/test/rbs/rbi_prototype_test.rb b/test/rbs/rbi_prototype_test.rb
index 5b06cb650..8f0107a0a 100644
--- a/test/rbs/rbi_prototype_test.rb
+++ b/test/rbs/rbi_prototype_test.rb
@@ -546,4 +546,25 @@ class Dir[out X, in Y, Z]
 end
     EOF
   end
+
+  def test_masgn
+    parser = RBI.new
+
+    parser.parse <<-EOF
+class Test
+  A, B, C = [1, 2, 3]
+end
+    EOF
+
+    assert_write parser.decls, <<-EOF
+class Test
+end
+
+Test::A: untyped
+
+Test::B: untyped
+
+Test::C: untyped
+    EOF
+  end
 end