Issue #25994: Added the close() method and the support of the context manager

protocol for the os.scandir() iterator.

Lib/test/test_os.py

@@ -2808,6 +2808,8 @@ class ExportsTests(unittest.TestCase):
 
 
 class TestScandir(unittest.TestCase):
+    check_no_resource_warning = support.check_no_resource_warning
+
     def setUp(self):
         self.path = os.path.realpath(support.TESTFN)
         self.addCleanup(support.rmtree, self.path)
@@ -3030,6 +3032,56 @@ class TestScandir(unittest.TestCase):
         for obj in [1234, 1.234, {}, []]:
             self.assertRaises(TypeError, os.scandir, obj)
 
+    def test_close(self):
+        self.create_file("file.txt")
+        self.create_file("file2.txt")
+        iterator = os.scandir(self.path)
+        next(iterator)
+        iterator.close()
+        # multiple closes
+        iterator.close()
+        with self.check_no_resource_warning():
+            del iterator
+
+    def test_context_manager(self):
+        self.create_file("file.txt")
+        self.create_file("file2.txt")
+        with os.scandir(self.path) as iterator:
+            next(iterator)
+        with self.check_no_resource_warning():
+            del iterator
+
+    def test_context_manager_close(self):
+        self.create_file("file.txt")
+        self.create_file("file2.txt")
+        with os.scandir(self.path) as iterator:
+            next(iterator)
+            iterator.close()
+
+    def test_context_manager_exception(self):
+        self.create_file("file.txt")
+        self.create_file("file2.txt")
+        with self.assertRaises(ZeroDivisionError):
+            with os.scandir(self.path) as iterator:
+                next(iterator)
+                1/0
+        with self.check_no_resource_warning():
+            del iterator
+
+    def test_resource_warning(self):
+        self.create_file("file.txt")
+        self.create_file("file2.txt")
+        iterator = os.scandir(self.path)
+        next(iterator)
+        with self.assertWarns(ResourceWarning):
+            del iterator
+            support.gc_collect()
+        # exhausted iterator
+        iterator = os.scandir(self.path)
+        list(iterator)
+        with self.check_no_resource_warning():
+            del iterator
+
 
 if __name__ == "__main__":
     unittest.main()