From 5843616c78ba9d2798d58f05543a5fe8c749d093 Mon Sep 17 00:00:00 2001
From: Stan Lo <stan001212@gmail.com>
Date: Mon, 1 Jan 2024 17:40:35 +0000
Subject: [PATCH] Make show_source resolve top-level constant names (#831)

---
 lib/irb/source_finder.rb         |  2 +-
 test/irb/cmd/test_show_source.rb | 28 ++++++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/lib/irb/source_finder.rb b/lib/irb/source_finder.rb
index 659d4200f..4e9cdc462 100644
--- a/lib/irb/source_finder.rb
+++ b/lib/irb/source_finder.rb
@@ -19,7 +19,7 @@ def initialize(irb_context)
     def find_source(signature, super_level = 0)
       context_binding = @irb_context.workspace.binding
       case signature
-      when /\A[A-Z]\w*(::[A-Z]\w*)*\z/ # Const::Name
+      when /\A(::)?[A-Z]\w*(::[A-Z]\w*)*\z/ # Const::Name
         eval(signature, context_binding) # trigger autoload
         base = context_binding.receiver.yield_self { |r| r.is_a?(Module) ? r : Object }
         file, line = base.const_source_location(signature)
diff --git a/test/irb/cmd/test_show_source.rb b/test/irb/cmd/test_show_source.rb
index cedec8aa6..12abae3c7 100644
--- a/test/irb/cmd/test_show_source.rb
+++ b/test/irb/cmd/test_show_source.rb
@@ -272,5 +272,33 @@ def foo
 
       assert_match(%r[#{@ruby_file.to_path}:2\s+def foo\r\n  end], out)
     end
+
+    def test_show_source_with_double_colons
+      write_ruby <<~RUBY
+        class Foo
+        end
+
+        class Foo
+          class Bar
+          end
+        end
+
+        binding.irb
+      RUBY
+
+      out = run_ruby_file do
+        type "show_source ::Foo"
+        type "exit"
+      end
+
+      assert_match(%r[#{@ruby_file.to_path}:1\s+class Foo\r\nend], out)
+
+      out = run_ruby_file do
+        type "show_source ::Foo::Bar"
+        type "exit"
+      end
+
+      assert_match(%r[#{@ruby_file.to_path}:5\s+class Bar\r\n  end], out)
+    end
   end
 end