As an API caller, I expect MD5s and file reference URLs to have real values and not the string "null"

[nutjob4life]

🐛 Describe the bug

When using the bundle's collections endpoint (/bundles/{lidvid}/collections) on urn:nasa:pds:insight_documents::2.0 with start=0 and limit=49 with the following fields:

• ops:Data_File_Info.ops:file_ref
• ops:Data_File_Info.ops:md5_checksum
• ops:Label_File_Info.ops:file_ref
• ops:Label_File_Info.ops:md5_checksum

the properties for ops:Data_File_Info.ops:file_ref, ops:Data_File_Info.ops:md5_checksum, ops:Label_File_Info.ops:file_ref, and ops:Label_File_Info.ops:md5_checksum do not contain URLs or MD5 digests, but instead contain the literal string:

null

👉 Also: It'd be great if instead of {"values": […]} appearing in properties, that we just had the array […] without the single key-value dict wrapper.

🧐 Expected behavior

Rather than null for file references, there should be URLs to files. Similarly, rather than null for MD5s, there should be strings of hexadecimal digits. This used to work back in April 2021 (but back then, there wasn't this weird extra values dict everywhere either.)

👉 And: we'd just have arrays […] and not {"values": […]}.

🧪 Test Data

Try running:

curl \
    --silent \
    --request GET \
    --header 'Accept: application/json' \
    'https://pds-gamma.jpl.nasa.gov/api/bundles/urn%3Anasa%3Apds%3Ainsight_documents%3A%3A2.0/collections?start=0&limit=49&fields=ops%3AData_File_Info.ops%3Afile_ref&fields=ops%3AData_File_Info.ops%3Amd5_checksum&fields=ops%3ALabel_File_Info.ops%3Afile_ref&fields=ops%3ALabel_File_Info.ops%3Amd5_checksum&only-summary=false' \
    | json_pp

and look at all the nulls and values. Or try the Swagger interactive UI:

🧩 Related issues

• Improvements per API updates to remove workarounds from code deep-archive#106
• error 500 on GET /collections/:lidvid:/products #17

⚙️ Engineering Details

• Fix implementation issue
• Add regression test ensuring this does not happen again (this is a regression in the system)