From 30938a8278a5e9ad800a2fb4b28a6c6a6ffb5191 Mon Sep 17 00:00:00 2001
From: Martin Diehl <mail@martin-diehl.net>
Date: Thu, 5 Nov 2020 21:38:00 +0100
Subject: [PATCH] correct order (brackets)

---
 python/damask/_vtk.py    | 2 +-
 python/tests/test_VTK.py | 7 ++++---
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/python/damask/_vtk.py b/python/damask/_vtk.py
index 9cfcca2ec..942be4f1f 100644
--- a/python/damask/_vtk.py
+++ b/python/damask/_vtk.py
@@ -199,7 +199,7 @@ class VTK:
 
         default_ext = '.'+writer.GetDefaultFileExtension()
         ext = Path(fname).suffix
-        writer.SetFileName(str(fname)+default_ext if default_ext != ext else '')
+        writer.SetFileName(str(fname)+(default_ext if default_ext != ext else ''))
 
         if compress:
             writer.SetCompressorTypeToZLib()
diff --git a/python/tests/test_VTK.py b/python/tests/test_VTK.py
index 70d91659a..bab6051b0 100644
--- a/python/tests/test_VTK.py
+++ b/python/tests/test_VTK.py
@@ -98,9 +98,10 @@ class TestVTK:
         with pytest.raises(TypeError):
             VTK.load(name,dataset_type)
 
-    def test_invalid_extension_write(self,default):
-        with pytest.raises(ValueError):
-            default.save('default.txt')
+    def test_add_extension(self,tmp_path,default):
+        default.save(tmp_path/'default.txt',parallel=False)
+        assert os.path.isfile(tmp_path/'default.txt.vtr')
+
 
     def test_invalid_get(self,default):
         with pytest.raises(ValueError):