From dcf9d77b45bcca3193a310e1a0f496e2d74cfc81 Mon Sep 17 00:00:00 2001
From: eileencodes <eileencodes@gmail.com>
Date: Tue, 16 Jan 2024 15:50:45 -0500
Subject: [PATCH] [Prism] Implement defined? for PM_BEGIN_NODE

Ruby code:

```ruby
defined?(begin; 1; end)
```

Instructions:

```
"********* Ruby *************"
== disasm: #<ISeq:<compiled>@<compiled>:1 (1,0)-(59,23)>
0000 putobject                              "expression"              (  59)[Li]
0002 leave
"********* PRISM *************"
== disasm: #<ISeq:<compiled>@<compiled>:58 (58,0)-(58,23)>
0000 putobject                              "expression"              (  58)[Li]
0002 leave
```

Related: ruby/prism#2188
---
 prism_compile.c                 | 1 +
 test/ruby/test_compile_prism.rb | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/prism_compile.c b/prism_compile.c
index f12a0c4944..2a083220c3 100644
--- a/prism_compile.c
+++ b/prism_compile.c
@@ -2462,6 +2462,7 @@ pm_compile_defined_expr0(rb_iseq_t *iseq, const pm_node_t *node, LINK_ANCHOR *co
           }
       }
       case PM_AND_NODE:
+      case PM_BEGIN_NODE:
       case PM_BREAK_NODE:
       case PM_DEFINED_NODE:
       case PM_FLOAT_NODE:
diff --git a/test/ruby/test_compile_prism.rb b/test/ruby/test_compile_prism.rb
index eb183cca58..3f416c1781 100644
--- a/test/ruby/test_compile_prism.rb
+++ b/test/ruby/test_compile_prism.rb
@@ -225,6 +225,8 @@ module Prism
       assert_prism_eval("defined?(return)")
       assert_prism_eval("defined?(retry)")
 
+      assert_prism_eval("defined?(begin; 1; end)")
+
       assert_prism_eval("defined?(defined?(a))")
       assert_prism_eval('defined?(:"#{1}")')
       assert_prism_eval("defined?(`echo #{1}`)")