Add tests for deserializing empty files

datafiles/tests/test_formats.py

@@ -1,11 +1,31 @@
 # pylint: disable=unused-variable
 
-from pathlib import Path
+
+import pytest
 
 from datafiles import formats
 
 
 def describe_deserialize():
-    def it_rejects_unknown_extensions(expect):
+    @pytest.fixture
+    def path(tmp_path):
+        path = tmp_path / "sample"
+        path.write_text("")
+        return path
+
+    def with_empty_yaml_file(expect, path):
+        data = formats.deserialize(path, '.yaml')
+        expect(data) == {}
+
+    def with_empty_json_file(expect, path):
+        path.write_text("{}")
+        data = formats.deserialize(path, '.json')
+        expect(data) == {}
+
+    def with_empty_toml_file(expect, path):
+        data = formats.deserialize(path, '.toml')
+        expect(data) == {}
+
+    def with_unknown_extension(expect, path):
         with expect.raises(ValueError):
-            formats.deserialize(Path(), '.xyz')
+            formats.deserialize(path, '.xyz')