Add test case

tests/pytests/unit/utils/test_atomicfile.py

@@ -0,0 +1,27 @@
+"""
+Tests for atomicfile utility module.
+"""
+
+import pytest
+
+import salt.utils.files
+from salt.utils.atomicfile import atomic_open
+
+
+@pytest.mark.skip_on_windows(reason="Not a Windows test")
+def test_atomicfile_respects_umask(tmp_path):
+    """
+    Test that creating a file using atomic_open respects the umask, instead of
+    creating the file with 0600 perms.
+    """
+    new_file = tmp_path / "foo"
+    contents = "bar"
+
+    # Set the umask specifically for this test so that we know what the mode of
+    # the created file should be.
+    with salt.utils.files.set_umask(0o022):
+        with atomic_open(str(new_file), "w") as fh_:
+            fh_.write(contents)
+
+    assert new_file.read_text() == contents
+    assert oct(new_file.stat().st_mode)[-3:] == "644"