Increase test coverage

src/rechunk_data/tests/conftest.py

@@ -31,6 +31,15 @@ def small_chunk() -> Generator[Tuple[int, int, int, int], None, None]:
     yield (1, 1, 24, 24)
 
 
+@pytest.fixture(scope="session")
+def empty_data() -> Generator[xr.Dataset, None, None]:
+    """Create an empty datasset."""
+
+    yield xr.Dataset(
+        {"tas_bnds": xr.DataArray(["hallo"], name="tas_bnds", dims=("lon",))}
+    )
+
+
 @pytest.fixture(scope="session")
 def large_chunk() -> Generator[Tuple[int, int, int, int], None, None]:
     """Define tuple for smaller chunks sizes."""