diff --git a/src/yt_napari/_ds_cache.py b/src/yt_napari/_ds_cache.py
index 882850f..51ef771 100644
--- a/src/yt_napari/_ds_cache.py
+++ b/src/yt_napari/_ds_cache.py
@@ -1,3 +1,7 @@
+import os.path
+from os import PathLike
+from typing import Optional
+
 import yt
 
 from yt_napari import _special_loaders
@@ -42,11 +46,11 @@ def check_then_load(self, filename: str, cache_if_not_found: bool = True):
         if self.exists(filename):
             ytnapari_log.info(f"loading {filename} from cache.")
             return self.get_ds(filename)
-        elif filename.startswith("_ytnapari") and hasattr(_special_loaders, filename):
+        elif callable_name := _check_for_special(filename):
             # the filename is actually a function handle! get it, call it
-            # this allows yt-napari to to use all the yt fake datasets in
+            # this allows yt-napari to use all the yt fake datasets in
             # testing without saving them to disk.
-            ds_callable = getattr(_special_loaders, filename)
+            ds_callable = getattr(_special_loaders, callable_name)
             ds = ds_callable()
         else:
             ds = yt.load(filename)
@@ -57,3 +61,12 @@ def check_then_load(self, filename: str, cache_if_not_found: bool = True):
 
 
 dataset_cache = DatasetCache()
+
+
+def _check_for_special(filename: PathLike) -> Optional[str]:
+    # check if a "filename" is one of our short-circuiting special loaders
+    # and return the function name if it is valid.
+    basename = os.path.basename(filename)
+    if basename.startswith("_ytnapari") and hasattr(_special_loaders, basename):
+        return str(basename)
+    return None
diff --git a/src/yt_napari/_tests/test_metadata_widget.py b/src/yt_napari/_tests/test_metadata_widget.py
new file mode 100644
index 0000000..a1e1cdd
--- /dev/null
+++ b/src/yt_napari/_tests/test_metadata_widget.py
@@ -0,0 +1,25 @@
+from yt_napari._widget_matadata import LayersList, MetadataWidget
+
+
+def test_widget_reader(make_napari_viewer):
+    viewer = make_napari_viewer()
+    r = MetadataWidget(napari_viewer=viewer)
+    r.metadata_input_container.filename.value = "_ytnapari_load_grid"
+    r.inspect_file()
+    r.inspect_file()  # do it again to hit that clear statement
+
+    assert "stream" in r.field_lists.keys()
+
+    r.field_lists["stream"].expand()
+    r.field_lists["stream"].expand()
+
+    assert "domain_left_edge" in r.array_vals.keys()
+    r.array_vals["domain_left_edge"].update_units("km")
+    r.deleteLater()
+
+
+def test_layer_list():
+    ll = LayersList("test_layer", range(0, 10), expand=False)
+    ll.expand()
+    assert ll.currently_expanded is True
+    ll.deleteLater()
diff --git a/src/yt_napari/_widget_matadata.py b/src/yt_napari/_widget_matadata.py
index 1f78f4b..622a88e 100644
--- a/src/yt_napari/_widget_matadata.py
+++ b/src/yt_napari/_widget_matadata.py
@@ -46,8 +46,10 @@ def inspect_file(self):
                 self.layout().removeWidget(list_widget)
                 list_widget.setParent(None)
         self.widgets_to_clear = []
-
+        self.field_lists = {}
+        self.array_vals = {}
         py_kwargs = {}
+
         _gui_utilities.translator.get_pydantic_kwargs(
             self.metadata_input_container, _data_model.MetadataModel, py_kwargs
         )
@@ -62,6 +64,7 @@ def inspect_file(self):
         for attr, val in meta_data_dict.items():
             if isinstance(val, unyt_array):
                 newid = UnytArrayQWidget(attr, val)
+                self.array_vals[attr] = newid
             else:
                 newid = QLabel(f"{attr}: {str(val)}")
             self.widgets_to_clear.append(newid)
@@ -72,6 +75,7 @@ def inspect_file(self):
         for ftype, fields in fields_by_type.items():
             new_field_list = LayersList(ftype, fields, ilist < 3)
             ilist += 1
+            self.field_lists[ftype] = new_field_list
             self.widgets_to_clear.append(new_field_list)
             self.layout().addWidget(new_field_list)
 
@@ -80,14 +84,6 @@ def inspect_file(self):
 # https://stackoverflow.com/questions/11077793/is-there-a-standard-component-for-collapsible-panel-in-qt
 
 
-class CustomQStandardItem(QStandardItem):
-    def __init__(self, icon, text):
-        super().__init__(icon, text)
-
-    def dropMimeData(self, data, action, row, column, parent):
-        pass
-
-
 class LayersList(QWidget):
     """
     LayerList class which acts as collapsable list.
@@ -113,7 +109,7 @@ def __init__(self, name, layers, expand=True):
         self.main_layout.addWidget(self.layer_list)
         self.expand_button.clicked.connect(self.expand)
         self.setLayout(self.main_layout)
-        self.resized_size = 16.5 * len(layers)
+        self.resized_size = int(16 * len(layers))
         if not expand:
             self.expand()