https://bugs.ruby-lang.org/issues/4592

gistfile1.diff

diff --git a/lib/tempfile.rb b/lib/tempfile.rb
index 8bdf086..fbe0e7d 100644
--- a/lib/tempfile.rb
+++ b/lib/tempfile.rb
@@ -194,6 +194,15 @@ class Tempfile < DelegateClass(File)
     ObjectSpace.undefine_finalizer(self)
   end
 
+  def mv(destination_path)
+    raise TypeError, "unlinked Tempfile" unless self.path
+    raise ArgumentError, "cannot move to the same path" if destination_path == self.path
+    _close
+    File.rename(self.path, destination_path)
+    unlink
+    ObjectSpace.undefine_finalizer(self)
+  end
+
   # Unlinks (deletes) the file from the filesystem. One should always unlink
   # the file after using it, as is explained in the "Explicit close" good
   # practice section in the Tempfile overview:
diff --git a/test/test_tempfile.rb b/test/test_tempfile.rb
index 1462a98..000cd2d 100644
--- a/test/test_tempfile.rb
+++ b/test/test_tempfile.rb
@@ -63,6 +63,25 @@ class TestTempfile < Test::Unit::TestCase
     assert_match(/\.txt$/, File.basename(t.path))
   end
 
+  def test_mv
+    t = tempfile("foo")
+    path = t.path
+
+    assert_raise ArgumentError do
+      t.mv(path)
+    end
+
+    dest_path = File.expand_path("../bar", File.dirname(path))
+    begin
+      t.mv(dest_path)
+      assert !File.exist?(path)
+      assert_nil t.path
+      assert File.exist?(dest_path)
+    ensure
+      File.unlink(dest_path) if File.exist?(dest_path)
+    end
+  end
+
   def test_unlink
     t = tempfile("foo")
     path = t.path

gistfile1.txt

diff --git a/lib/tempfile.rb b/lib/tempfile.rb
index 8bdf086..8d45c3d 100644
--- a/lib/tempfile.rb
+++ b/lib/tempfile.rb
@@ -194,6 +194,14 @@ class Tempfile < DelegateClass(File)
     ObjectSpace.undefine_finalizer(self)
   end
 
+  def mv(destination_path)
+    raise TypeError, "unlinked Tempfile" unless self.path
+    _close
+    File.rename(self.path, destination_path)
+    unlink
+    ObjectSpace.undefine_finalizer(self)
+  end
+
   # Unlinks (deletes) the file from the filesystem. One should always unlink
   # the file after using it, as is explained in the "Explicit close" good
   # practice section in the Tempfile overview:
diff --git a/test/test_tempfile.rb b/test/test_tempfile.rb
index 1462a98..5c0d6bf 100644
--- a/test/test_tempfile.rb
+++ b/test/test_tempfile.rb
@@ -63,6 +63,21 @@ class TestTempfile < Test::Unit::TestCase
     assert_match(/\.txt$/, File.basename(t.path))
   end
 
+  def test_mv
+    t = tempfile("foo")
+    path = t.path
+
+    dest_path = File.expand_path("../bar", File.dirname(path))
+    begin
+      t.mv(dest_path)
+      assert !File.exist?(path)
+      assert_nil t.path
+      assert File.exist?(dest_path)
+    ensure
+      File.unlink(dest_path) if File.exist?(dest_path)
+    end
+  end
+
   def test_unlink
     t = tempfile("foo")
     path = t.path