From db9f5fc91620b799c8829d0ca69bf72564a16e14 Mon Sep 17 00:00:00 2001
From: eileencodes <eileencodes@gmail.com>
Date: Wed, 17 Jan 2024 11:40:01 -0500
Subject: [PATCH] [Prism] Implement defined? for PM_UNLESS_NODE

Ruby code:

```ruby
defined?(unless true; 1; end)
```

Instructions:

```
"********* Ruby *************"
== disasm: #<ISeq:<compiled>@<compiled>:1 (1,0)-(59,16)>
0000 putobject                              "expression"              (  59)[Li]
0002 leave
"********* PRISM *************"
== disasm: #<ISeq:<compiled>@<compiled>:58 (58,0)-(58,16)>
0000 putobject                              "expression"              (  58)[Li]
0002 leave
```

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

diff --git a/prism_compile.c b/prism_compile.c
index ffabda7175..876278166b 100644
--- a/prism_compile.c
+++ b/prism_compile.c
@@ -2571,6 +2571,7 @@ pm_compile_defined_expr0(rb_iseq_t *iseq, const pm_node_t *node, LINK_ANCHOR *co
       case PM_SOURCE_LINE_NODE:
       case PM_STRING_NODE:
       case PM_SYMBOL_NODE:
+      case PM_UNLESS_NODE:
       case PM_UNTIL_NODE:
       case PM_WHILE_NODE:
       case PM_X_STRING_NODE:
diff --git a/test/ruby/test_compile_prism.rb b/test/ruby/test_compile_prism.rb
index 1f9ce84bfa..f1274fccf5 100644
--- a/test/ruby/test_compile_prism.rb
+++ b/test/ruby/test_compile_prism.rb
@@ -262,6 +262,7 @@ module Prism
       assert_prism_eval("defined?(class << self; end)")
       assert_prism_eval("defined?(while a != 1; end)")
       assert_prism_eval("defined?(until a == 1; end)")
+      assert_prism_eval("defined?(unless true; 1; end)")
     end
 
     def test_GlobalVariableReadNode