test/pybind/rbd: fix tests that compare strings with b''

assert_not_equal(b'', self.image.id()) is bogus because Image::id()
returns a string (str), not bytes.  If the types don't match, values
are guaranteed to not match.

The same goes for Image::block_name_prefix().

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
(cherry picked from commit 05f7e4f2025c435dca8ae0b34f65425afbc212b5)

diff --git a/src/test/pybind/test_rbd.py b/src/test/pybind/test_rbd.py
index 01ac8b1e53808573ab34e9543304f7e0f954da9b..935e584bd6ac309c67022bb80a1d04e75a3cede2 100644 (file)
--- a/src/test/pybind/test_rbd.py
+++ b/src/test/pybind/test_rbd.py
@@ -627,10 +627,14 @@ class TestImage(object):
 
     @require_new_format()
     def test_id(self):
-        assert_not_equal(b'', self.image.id())
+        id = self.image.id()
+        assert isinstance(id, str)
+        assert len(id) > 0
 
     def test_block_name_prefix(self):
-        assert_not_equal(b'', self.image.block_name_prefix())
+        block_name_prefix = self.image.block_name_prefix()
+        assert isinstance(block_name_prefix, str)
+        assert len(block_name_prefix) > 0
 
     def test_data_pool_id(self):
         assert_greater_equal(self.image.data_pool_id(), 0)