[EXPERIMENTAL] Make Module#name return a frozen String

    * Always the same frozen String for a given Module or Class.
    * Avoids extra allocations whenever calling Module#name.
    * See [Feature #16150]

1 files changed, 19 insertions, 5 deletions

diff --git a/spec/ruby/core/module/name_spec.rb b/spec/ruby/core/module/name_spec.rb
index d64684319c..36a91f5be5 100644
--- a/spec/ruby/core/module/name_spec.rb
+++ b/spec/ruby/core/module/name_spec.rb
@@ -102,13 +102,27 @@ describe "Module#name" do
     m::N.name.should == "ModuleSpecs::Anonymous::E::N"
   end
 
-  it "returns a mutable string" do
-    ModuleSpecs.name.frozen?.should be_false
+  ruby_version_is ""..."2.7" do
+    it "returns a mutable string" do
+      ModuleSpecs.name.frozen?.should be_false
+    end
+
+    it "returns a mutable string that when mutated does not modify the original module name" do
+      ModuleSpecs.name << "foo"
+
+      ModuleSpecs.name.should == "ModuleSpecs"
+    end
   end
 
-  it "returns a mutable string that when mutated does not modify the original module name" do
-    ModuleSpecs.name << "foo"
+  ruby_version_is "2.7" do
+    it "returns a frozen String" do
+      ModuleSpecs.name.frozen?.should == true
+    end
 
-    ModuleSpecs.name.should == "ModuleSpecs"
+    it "always returns the same String for a given Module" do
+      s1 = ModuleSpecs.name
+      s2 = ModuleSpecs.name
+      s1.should equal(s2)
+    end
   end
 end