Improve retrieval of original name

Having used AIPscan a little more, leaving the name blank is strange
to look at, but we also cannot always retrieve the original name. We
do our best to a) retrieve the name in this commit, as well as b)
populate the name with the transfer UUID as an alternative.

AIPscan/Aggregator/mets_parse_helpers.py

@@ -49,31 +49,32 @@ def get_aip_original_name(mets):
     # Negated as we're going to want to remove this length of values.
     NAMESUFFIX = -len("-00000000-0000-0000-0000-000000000000")
 
+    # Other intellectual entities exist in the METS, i.e. for empty
+    # directories. We can identify those with an invalid name prefix.
+    INVALID_NAMEPREFIX = "%transferDirectory%"
+
     NAMESPACES = {u"premis": u"http://www.loc.gov/premis/v3"}
     ELEM_ORIGINAL_NAME_PATTERN = ".//premis:originalName"
 
-    FIRST_DMDSEC = "dmdSec_1"
-
     original_name = ""
     for fsentry in mets.all_files():
-        try:
-            dmdsec = fsentry.dmdsecs[0]
-            if dmdsec.id_string != FIRST_DMDSEC:
-                continue
+        for dmdsec in fsentry.dmdsecs:
             dmd_element = dmdsec.serialize()
             full_name = dmd_element.find(
                 ELEM_ORIGINAL_NAME_PATTERN, namespaces=NAMESPACES
             )
+            if full_name is not None and full_name.text.startswith(INVALID_NAMEPREFIX):
+                # We don't want this value, it will usually represent an
+                # directory entity.
+                continue
             try:
                 original_name = full_name.text[:NAMESUFFIX]
             except AttributeError:
-                pass
-            break
-        except IndexError:
-            pass
+                continue
 
+    # There should be a transfer name in every METS.
     if original_name == "":
-        raise METSError()
+        raise METSError("Cannot locate transfer name in METS")
 
     return original_name
 

AIPscan/Aggregator/tasks.py

@@ -294,7 +294,7 @@ def get_mets(
     except METSError:
         # Some other error with the METS file that we might want to
         # log and act upon.
-        originalName = ""
+        originalName = packageUUID
 
     aip = create_aip_object(
         package_uuid=packageUUID,

AIPscan/Aggregator/tests/test_mets.py

@@ -13,19 +13,30 @@
 
 
 @pytest.mark.parametrize(
-    "fixture_path, transfer_name",
+    "fixture_path, transfer_name, mets_error",
     [
-        (os.path.join("features_mets", "features-mets.xml"), "myTransfer"),
-        (os.path.join("iso_mets", "iso_mets.xml"), "iso"),
+        (os.path.join("features_mets", "features-mets.xml"), "myTransfer", False),
+        (os.path.join("iso_mets", "iso_mets.xml"), "iso", False),
+        (os.path.join("original_name_mets", "dataverse_example.xml"), "", True),
+        (
+            os.path.join("original_name_mets", "document-empty-dirs.xml"),
+            "empty-dirs",
+            False,
+        ),
     ],
 )
-def test_get_aip_original_name(fixture_path, transfer_name):
+def test_get_aip_original_name(fixture_path, transfer_name, mets_error):
     """Make sure that we can reliably get original name from the METS
     file given we haven't any mets-reader-writer helpers.
     """
     script_dir = os.path.dirname(os.path.realpath(__file__))
     mets_file = os.path.join(script_dir, FIXTURES_DIR, fixture_path)
     mets = metsrw.METSDocument.fromfile(mets_file)
+    if mets_error:
+        # Function should raise an error to work with.
+        with pytest.raises(mets_parse_helpers.METSError):
+            _ = mets_parse_helpers.get_aip_original_name(mets)
+        return
     assert mets_parse_helpers.get_aip_original_name(mets) == transfer_name
     # Test the same works with a string.
     with open(mets_file, "rb") as mets_stream: