Fix slicing of FileManager

changelog/199.bugfix.1.rst

@@ -0,0 +1,2 @@
+Fix a bug where ``FileManager.download`` would fail if there was not an
+asdf file or quality report PDF in inventory.

changelog/199.bugfix.rst

@@ -0,0 +1,2 @@
+Fix an issue with slicing a dataset where the slicing wouldn't work correctly
+if the first axis of the data array has length one.

dkist/conftest.py

@@ -263,3 +263,27 @@ def simple_tiled_dataset(dataset):
         ds.meta['inventory'] = dataset.meta['inventory']
     dataset_array = np.array(datasets).reshape((2,2))
     return TiledDataset(dataset_array, dataset.meta['inventory'])
+
+
+@pytest.fixture
+def small_visp_dataset():
+    """
+    This fixture is used to test when the array in the FITS file has a length
+    one NAXIS 3.
+    """
+    # This asdf file wont work with sunpy less than 4
+    pytest.importorskip("sunpy", "4.0.0")
+
+    # This dataset was generated by the following code:
+    # from dkist_data_simulator.spec214.visp import SimpleVISPDataset
+    # from dkist_inventory.asdf_generator import dataset_from_fits
+    # import astropy.units as u
+
+    # ds = SimpleVISPDataset(n_maps=1, n_steps=3, n_stokes=1, time_delta=10,
+    #                        linewave=500*u.nm, detector_shape=(10, 25))
+    # ds.generate_files(vispdir)
+    # dataset_from_fits(vispdir, "test_visp.asdf")
+
+    vispdir = Path(rootdir) / "small_visp"
+    with asdf.open(vispdir / "test_visp.asdf") as f:
+        return f.tree['dataset']