From 21f3b5c73e86bfe5ba4a61541b64cf228373d4ce Mon Sep 17 00:00:00 2001
From: Shannon Skipper <shannonskipper@gmail.com>
Date: Tue, 7 May 2024 16:21:26 -0700
Subject: [PATCH] Add an Enumerator#eager that returns `self`

---
 enumerator.c           | 14 ++++++++++++++
 test/ruby/test_enum.rb |  4 ++++
 2 files changed, 18 insertions(+)

diff --git a/enumerator.c b/enumerator.c
index 193a865dbc5536..8622101bedfda3 100644
--- a/enumerator.c
+++ b/enumerator.c
@@ -1216,6 +1216,19 @@ append_method(VALUE obj, VALUE str, ID default_method, VALUE default_args)
     return str;
 }
 
+/*
+ *  call-seq:
+ *     enumerator.eager -> enumerator
+ *
+ *  Returns self.
+ */
+
+static VALUE
+enumerator_eager(VALUE obj)
+{
+    return obj;
+}
+
 /*
  * call-seq:
  *   e.inspect  -> string
@@ -4478,6 +4491,7 @@ InitVM_Enumerator(void)
     rb_define_method(rb_cEnumerator, "inspect", enumerator_inspect, 0);
     rb_define_method(rb_cEnumerator, "size", enumerator_size, 0);
     rb_define_method(rb_cEnumerator, "+", enumerator_plus, 1);
+    rb_define_method(rb_mEnumerable, "eager", enumerator_eager, 0);
     rb_define_method(rb_mEnumerable, "chain", enum_chain, -1);
 
     /* Lazy */
diff --git a/test/ruby/test_enum.rb b/test/ruby/test_enum.rb
index 7503e062726d8e..e0e127476b04e5 100644
--- a/test/ruby/test_enum.rb
+++ b/test/ruby/test_enum.rb
@@ -102,6 +102,10 @@ def each
     end
   end
 
+  def test_eager
+    assert_equal(@obj, @obj.eager)
+  end
+
   def test_find
     assert_equal(2, @obj.find {|x| x % 2 == 0 })
     assert_equal(nil, @obj.find {|x| false })