bpo-32695: Docs and tests for compresslevel and preset kwargs in tarfile (GH-21470)

Co-Authored-By: Bo Bayles <bbayles@gmail.com>

1 files changed, 18 insertions, 3 deletions

diff --git a/Lib/test/test_tarfile.py b/Lib/test/test_tarfile.py
index 817e6f1..cfdda24 100644
--- a/Lib/test/test_tarfile.py
+++ b/Lib/test/test_tarfile.py
@@ -1706,15 +1706,30 @@ class CreateTest(WriteTestBase, unittest.TestCase):
 
 
 class GzipCreateTest(GzipTest, CreateTest):
-    pass
+
+    def test_create_with_compresslevel(self):
+        with tarfile.open(tmpname, self.mode, compresslevel=1) as tobj:
+            tobj.add(self.file_path)
+        with tarfile.open(tmpname, 'r:gz', compresslevel=1) as tobj:
+            pass
 
 
 class Bz2CreateTest(Bz2Test, CreateTest):
-    pass
+
+    def test_create_with_compresslevel(self):
+        with tarfile.open(tmpname, self.mode, compresslevel=1) as tobj:
+            tobj.add(self.file_path)
+        with tarfile.open(tmpname, 'r:bz2', compresslevel=1) as tobj:
+            pass
 
 
 class LzmaCreateTest(LzmaTest, CreateTest):
-    pass
+
+    # Unlike gz and bz2, xz uses the preset keyword instead of compresslevel.
+    # It does not allow for preset to be specified when reading.
+    def test_create_with_preset(self):
+        with tarfile.open(tmpname, self.mode, preset=1) as tobj:
+            tobj.add(self.file_path)
 
 
 class CreateWithXModeTest(CreateTest):