Fix febus format empty file (#492)

* work on adding neubrex

* fix febus format issue

dascore/io/febus/utils.py

@@ -75,7 +75,7 @@ def _get_febus_version_str(hdf_fi) -> str:
             # Hopefully this is the file version...
             version = unbyte(source.attrs.get("Version", version)).split(".")[0]
             is_febus = is_febus and expected_source_attrs.issubset(set(source.attrs))
-    if is_febus:
+    if inst_keys and is_febus:
         return version
     return ""
 

tests/test_io/test_io_core.py

@@ -7,6 +7,7 @@
 from pathlib import Path
 from typing import TypeVar
 
+import h5py
 import numpy as np
 import pandas as pd
 import pytest
@@ -260,6 +261,14 @@ def test_implements(self):
 class TestGetFormat:
     """Tests to ensure formats can be retrieved."""
 
+    @pytest.fixture(scope="class")
+    def empty_h5_path(self, tmpdir_factory):
+        """Create an empty HDF5 file."""
+        path = tmpdir_factory.mktemp("empty") / "empty.h5"
+        with h5py.File(path, "w"):
+            pass
+        return path
+
     def test_not_known(self, dummy_text_file):
         """Ensure a non-path/str object raises."""
         with pytest.raises(UnknownFiberFormatError):
@@ -279,6 +288,11 @@ def test_fiberio_directory(self, tmp_path_factory):
         assert fiber_io.name == name
         assert fiber_io.version == version
 
+    def test_empty_hdf5_no_format(self, empty_h5_path):
+        """Ensure the empty hdf5 dorsen't have a format."""
+        with pytest.raises(UnknownFiberFormatError):
+            dc.get_format(empty_h5_path)
+
 
 class TestScan:
     """Tests for scanning fiber files."""