From 334c261cc9ee125c4c4bfc65dec2e571af8944a2 Mon Sep 17 00:00:00 2001
From: Earlopain <14981592+Earlopain@users.noreply.github.com>
Date: Sun, 30 Mar 2025 13:28:36 +0200
Subject: [PATCH] [ruby/prism] Fix parser translator when splatting in pattern
 matching pin

Because it ends up treating it as a local variable, and `a.x`
is not a valid local variable name.

I'm not big on pattern matching, but conceptually it makes sense to me
to treat anything inside ^() to not be
pattern matching syntax?

https://github.com/ruby/prism/commit/80dbd85c45
---
 lib/prism/translation/parser/compiler.rb | 3 ++-
 test/prism/fixtures/patterns.txt         | 4 ++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/lib/prism/translation/parser/compiler.rb b/lib/prism/translation/parser/compiler.rb
index acf4e77ee4..1beccc30a1 100644
--- a/lib/prism/translation/parser/compiler.rb
+++ b/lib/prism/translation/parser/compiler.rb
@@ -1481,7 +1481,8 @@ module Prism
         # foo => ^(bar)
         #        ^^^^^^
         def visit_pinned_expression_node(node)
-          expression = builder.begin(token(node.lparen_loc), visit(node.expression), token(node.rparen_loc))
+          parts = node.expression.accept(copy_compiler(in_pattern: false)) # Don't treat * and similar as match_rest
+          expression = builder.begin(token(node.lparen_loc), parts, token(node.rparen_loc))
           builder.pin(token(node.operator_loc), expression)
         end
 
diff --git a/test/prism/fixtures/patterns.txt b/test/prism/fixtures/patterns.txt
index 09584e43eb..449dac619b 100644
--- a/test/prism/fixtures/patterns.txt
+++ b/test/prism/fixtures/patterns.txt
@@ -218,3 +218,7 @@ a in b, and c
 a in b, or c
 (a in b,) and c
 (a in b,) or c
+
+x => ^([*a.x])
+x => ^([**a.x])
+x => ^({ a: })