Fix TypeError in by_name() when name is not found (#83)

* Fix TypeError in by_name() when name is not found

When using `match="equals"` (the default), `by_name()` would return
`None` from `dict.get(name, None)` if the name wasn't found in the
lookup cache. This caused `len(matches)` on line 51 to raise:

    TypeError: object of type 'NoneType' has no len()

This fix changes the default value from `None` to `[]` (empty list),
making it consistent with the `match="contains"` branch which already
initializes `matches = []`.

* fix: move empty result check up before checking if user asked for all

* add(test): tests for consistent None return for by_name method

Author: ree-gupta

pipeline/src/additional_methods/by_name.py.txt

@@ -38,17 +38,17 @@
                     else:
                         cls._instance_lookup[key] = [instance]
         if match == "equals":
-            matches = cls._instance_lookup.get(name, None)
+            matches = cls._instance_lookup.get(name, [])
         elif match == "contains":
             matches = []
             for key, instances in cls._instance_lookup.items():
                 if name in key:
                     matches.extend(instances)
         else:
             raise ValueError("'match' must be either 'equals' or 'contains'")
-        if all:
+        if not matches: 
+            return None
+        elif all:
             return matches
-        elif len(matches) > 0:
-            return matches[0]
         else:
-            return None
+            return matches[0]

pipeline/tests/test_regressions.py

@@ -331,3 +331,17 @@ def test_issue0069(om):
     results = om.core.License.by_name("Creative Commons", all=True, match="contains")
     assert len(results) == 7
     assert all("CC" in r.short_name for r in results)
+
+@pytest.mark.parametrize("om", [openminds.latest])
+def test_pr0083(om):
+    # https://github.com/openMetadataInitiative/openMINDS_Python/pull/83
+    # by_name() should return None consistently
+    # when no matches are found, regardless of the 'all' parameter
+    
+    # all=False (default) should return None when no match is found
+    result = om.controlled_terms.BiologicalOrder.by_name("nonexistent_order_xyz")
+    assert result is None
+    
+    # all=True should also return None when no match is found
+    results = om.controlled_terms.BiologicalOrder.by_name("nonexistent_order_xyz", all=True)
+    assert results is None