BDMS 221 & 227: function to retrieve polymorphic table record

[jacob-a-brown]

Why

This PR addresses the following problem / context:

• Records from the parameter and status_history tables need to be easily retrieved for schemas and tests

How

Implementation summary - the following was changed / added / removed:

• A function to retrieve a record was put into services/util.py

Notes

Any special considerations, workarounds, or follow-up work to note?

• This only retrieves one function in a sorted list by start_date. I don't think that we need one to retrieve all records since that is easily done via the attribute from the mixins.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 11.11111% with 8 lines in your changes missing coverage. Please review.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
tests/__init__.py	11.11%	8 Missing ⚠️

Files with missing lines	Coverage Δ
tests/__init__.py	83.67% <11.11%> (-16.33%)	⬇️

... and 5 files with indirect coverage changes

[jirhiker]

where is this being used

[jacob-a-brown]

I'll use it in tests. I initially thought I'd use it throughout, but it may not actually be needed (I'm still developing responses, so TBD). From your comment on the well additional info PR I figured I'd put it in services/util.py, but if it's just used in tests should it go in tests/__init__.py?

[jacob-a-brown]

I need to add a check in there, too, that end_date is null

[jacob-a-brown]

I updated this to make sure end_date is not null, but since status_history is eagerly loaded for each thing object I don't need to use polymorphic_relationship in the API. So I've moved it to tests/__init__.py for use in tests only.