Added lock file to prevent file name collisions

tests/test_path_utils.py

@@ -1,6 +1,10 @@
 """ Test path_utils.py """
 
+
 def test_sanitize_filename():
+    """test sanitize_filename"""
+
+    # subtract 6 chars from max length of 255 to account for lock file extension
     from osxphotos.path_utils import sanitize_filename
     from osxphotos._constants import MAX_FILENAME_LEN
 
@@ -30,25 +34,25 @@ def test_sanitize_filename():
     filename = "foo" + "x" * 512
     new_filename = sanitize_filename(filename)
     assert len(new_filename) == MAX_FILENAME_LEN
-    assert new_filename == "foo" + "x" * 252
+    assert new_filename == "foo" + "x" * (252 - 6)
 
     # filename too long with extension
     filename = "x" * 512 + ".jpeg"
     new_filename = sanitize_filename(filename)
     assert len(new_filename) == MAX_FILENAME_LEN
-    assert new_filename == "x" * 250 + ".jpeg"
+    assert new_filename == "x" * (250 - 6) + ".jpeg"
 
     # more than one extension
     filename = "foo.bar" + "x" * 255 + ".foo.bar.jpeg"
     new_filename = sanitize_filename(filename)
     assert len(new_filename) == MAX_FILENAME_LEN
-    assert new_filename == "foo.bar" + "x" * 243 + ".jpeg"
+    assert new_filename == "foo.bar" + "x" * (243 - 6) + ".jpeg"
 
     # shorter than drop count
     filename = "foo." + "x" * 256
     new_filename = sanitize_filename(filename)
     assert len(new_filename) == MAX_FILENAME_LEN
-    assert new_filename == "foo." + "x" * 251
+    assert new_filename == "foo." + "x" * (251 - 6)
 
 
 def test_sanitize_dirname():
@@ -83,6 +87,7 @@ def test_sanitize_dirname():
     assert len(new_dirname) == MAX_DIRNAME_LEN
     assert new_dirname == "foo" + "x" * 252
 
+
 def test_sanitize_pathpart():
     from osxphotos.path_utils import sanitize_pathpart
     from osxphotos._constants import MAX_DIRNAME_LEN
@@ -114,4 +119,3 @@ def test_sanitize_pathpart():
     new_dirname = sanitize_pathpart(dirname)
     assert len(new_dirname) == MAX_DIRNAME_LEN
     assert new_dirname == "foo" + "x" * 252
-