2 files changed, 80 insertions, 3 deletions
diff --git a/spec/ruby/core/module/fixtures/set_temporary_name.rb b/spec/ruby/core/module/fixtures/set_temporary_name.rb
new file mode 100644
index 0000000000..901b3b94d1
--- /dev/null
+++ b/spec/ruby/core/module/fixtures/set_temporary_name.rb
@@ -0,0 +1,4 @@
+module ModuleSpecs
+  module SetTemporaryNameSpec
+  end
+end
diff --git a/spec/ruby/core/module/set_temporary_name_spec.rb b/spec/ruby/core/module/set_temporary_name_spec.rb
index f5886a3398..12541374ae 100644
--- a/spec/ruby/core/module/set_temporary_name_spec.rb
+++ b/spec/ruby/core/module/set_temporary_name_spec.rb
@@ -1,4 +1,5 @@
 require_relative '../../spec_helper'
+require_relative 'fixtures/set_temporary_name'
 
 ruby_version_is "3.3" do
   describe "Module#set_temporary_name" do
@@ -13,13 +14,34 @@ ruby_version_is "3.3" do
       m.name.should be_nil
     end
 
+    it "returns self" do
+      m = Module.new
+      m.set_temporary_name("fake_name").should.equal? m
+    end
+
     it "can assign a temporary name which is not a valid constant path" do
       m = Module.new
-      m.set_temporary_name("a::B")
-      m.name.should == "a::B"
+
+      m.set_temporary_name("name")
+      m.name.should == "name"
 
       m.set_temporary_name("Template['foo.rb']")
       m.name.should == "Template['foo.rb']"
+
+      m.set_temporary_name("a::B")
+      m.name.should == "a::B"
+
+      m.set_temporary_name("A::b")
+      m.name.should == "A::b"
+
+      m.set_temporary_name("A::B::")
+      m.name.should == "A::B::"
+
+      m.set_temporary_name("A::::B")
+      m.name.should == "A::::B"
+
+      m.set_temporary_name("A=")
+      m.name.should == "A="
     end
 
     it "can't assign empty string as name" do
@@ -43,7 +65,7 @@ ruby_version_is "3.3" do
       -> { Object.set_temporary_name("fake_name") }.should raise_error(RuntimeError, "can't change permanent name")
     end
 
-    it "can assign a temporary name to a nested module" do
+    it "can assign a temporary name to a module nested into an anonymous module" do
       m = Module.new
       module m::N; end
       m::N.name.should =~ /\A#<Module:0x\h+>::N\z/
@@ -55,6 +77,17 @@ ruby_version_is "3.3" do
       m::N.name.should be_nil
     end
 
+    it "discards a temporary name when an outer anonymous module gets a permanent name" do
+      m = Module.new
+      module m::N; end
+
+      m::N.set_temporary_name("fake_name")
+      m::N.name.should == "fake_name"
+
+      ModuleSpecs::SetTemporaryNameSpec::M = m
+      m::N.name.should == "ModuleSpecs::SetTemporaryNameSpec::M::N"
+    end
+
     it "can update the name when assigned to a constant" do
       m = Module.new
       m::N = Module.new
@@ -64,5 +97,45 @@ ruby_version_is "3.3" do
       m::M = m::N
       m::M.name.should =~ /\A#<Module:0x\h+>::M\z/m
     end
+
+    it "can reassign a temporary name repeatedly" do
+      m = Module.new
+
+      m.set_temporary_name("fake_name")
+      m.name.should == "fake_name"
+
+      m.set_temporary_name("fake_name_2")
+      m.name.should == "fake_name_2"
+    end
+
+    it "does not affect a name of a module nested into an anonymous module with a temporary name" do
+      m = Module.new
+      m::N = Module.new
+      m::N.name.should =~ /\A#<Module:0x\h+>::N\z/
+
+      m.set_temporary_name("foo")
+      m::N.name.should =~ /\A#<Module:0x\h+>::N\z/
+    end
+
+    it "keeps temporary name when assigned in an anonymous module" do
+      outer = Module.new
+      m = Module.new
+      m.set_temporary_name "m"
+      m.name.should == "m"
+      outer::M = m
+      m.name.should == "m"
+      m.inspect.should == "m"
+    end
+
+    it "keeps temporary name when assigned in an anonymous module and nested before" do
+      outer = Module.new
+      m = Module.new
+      outer::A = m
+      m.set_temporary_name "m"
+      m.name.should == "m"
+      outer::M = m
+      m.name.should == "m"
+      m.inspect.should == "m"
+    end
   end
 end