Check for Engin-injected parameter using the dependency function name

[karvozavr]

Compatibility fix for FastAPI>=0.121.3

https://fastapi.tiangolo.com/release-notes/#01213

Due to the recent FastAPI release making Depends object a dataclass, using custom Depends.__engin__ attribute is no longer possible.

The suggested fix leverages an approach which depends less on the internals of the FastAPI, and interacts with its public API — it checks for Depends.dependency function name (that is created by engin).

The only potential issue, is someone using the same dependency function name __inner_engin_dependency__, which is highly unlikely.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.96%. Comparing base (0a653fd) to head (b86d90b).
⚠️ Report is 4 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #65      +/-   ##
==========================================
- Coverage   90.97%   90.96%   -0.02%     
==========================================
  Files          19       19              
  Lines        1197     1195       -2     
  Branches      161      161              
==========================================
- Hits         1089     1087       -2     
  Misses         67       67              
  Partials       41       41              

Flag	Coverage Δ
macos-latest	90.04% <100.00%> (-0.02%)	⬇️
py3.10	90.54% <100.00%> (-0.02%)	⬇️
py3.11	90.54% <100.00%> (-0.02%)	⬇️
py3.12	90.54% <100.00%> (-0.02%)	⬇️
py3.13	90.54% <100.00%> (-0.02%)	⬇️
py3.14	90.55% <100.00%> (-0.02%)	⬇️
ubuntu-latest	90.04% <100.00%> (-0.02%)	⬇️
windows-latest	90.37% <100.00%> (-0.02%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[invokermain]

Looks good! Thanks for the fix.

I think it would be good to add a comment above the __inner_engin_dependency__ func explaining the name is special. I had already forgotten as I originally assumed the __engin__ attribute was used for much more than just powering the graph.

If you want you can also update the CHANGELOG.md or I can do it later. I will probably add an improvement to the engin check error message and release those two changes together.

[karvozavr]

@invokermain, I have added a CHANGELOG.md entry.

Please let me know what's the planned change to the engin check error message, maybe I could address it as well?

[invokermain]

See pull request here: #67. I've only added a failing test case so far.