[abhinavs1920]

Issue number: closes #8348

Summary

Changes

Function-based middleware can now declare Depends() parameters and a Request parameter, the same way route handlers can:

• MiddlewareFrame (sync) and AsyncMiddlewareFrame (async, both the coroutine and sync-in-thread paths) resolve Depends() parameters before calling the middleware.
• The per-request dependency cache is stored in app.context and shared with the route adapters, so a dependency used by both middleware and route is resolved only once.
• dependency_overrides and Request injection work for middleware dependencies.
• A middleware that short-circuits never triggers route dependency resolution.
• Signature inspection is cached on the callable, mirroring Route's caching, so there is no per-request overhead.
• Class-based middleware is intentionally out of scope for this PR, as discussed on the issue.

User experience

Before: a middleware declaring Annotated[UserDao, Depends(get_user_dao)] was called without that parameter being resolved, so the pattern from the issue (DAO injection into middleware) did not work.

After: the issue's example works as written - the dependency is resolved and injected, and shares its cache with route dependencies.

Testing

• 9 new tests in tests/functional/event_handler/required_dependencies/test_middleware_depends.py covering the acceptance criteria from the issue discussion: overrides, Request injection, sync + async middleware, short-circuit, single resolution across middleware and route, plus the issue's DAO example and a no-dependency backwards-compat check.
• tests/functional/event_handler/required_dependencies/: 511 passed.
• Full tests/functional/event_handler/ suite: passes except 2 failures in _pydantic/test_http_resolver_pydantic.py ASGI concurrency tests, which also fail on unpatched develop (pre-existing, unrelated).

@leandrodamascena - opening this early draft as you offered. Happy to iterate.

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[boring-cyborg]

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[leandrodamascena]

Hey @abhinavs1920, this looks great, thanks for the quick turnaround! I ran it locally with a few extra scenarios and it all holds up.

Before you take it out of draft, could you add a short section to the docs ("Combining middleware and Depends()" in api_gateway.md, the DAO example from the issue is perfect there), fix the truncated PR title, and add two tests for Router-level and route-level middleware with Depends? Then ping me and I'll do the final review.

[abhinavs1920]

Thanks for the quick look! All three are in: the docs section with the DAO example from the issue, the title is fixed, and there are now tests for Router-level and route-level middleware with Depends (required_dependencies suite still green). Ready for your final review whenever works.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.93%. Comparing base (bdd370b) to head (748684f).

Additional details and impacted files

@@           Coverage Diff            @@
##           develop    #8573   +/-   ##
========================================
  Coverage    96.93%   96.93%           
========================================
  Files          318      318           
  Lines        16005    16031   +26     
  Branches      1420     1423    +3     
========================================
+ Hits         15514    15540   +26     
  Misses         349      349           
  Partials       142      142           

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[leandrodamascena]

Thanks @abhinavs1920, this came out really well. I ran it with the current develop merged in and a few extra cases on top of your tests: forward-ref annotations, class-based middleware, functools.partial, bound methods, **kwargs, Request with validation on, and a ServiceError raised inside a middleware dependency, which now returns 401 thanks to #8568. All good. I pushed a small test for the bound-method path to cover the last two lines codecov flagged. Approving.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[boring-cyborg]

Awesome work, congrats on your first merged pull request and thank you for helping improve everyone's experience!

[powertools-for-aws-oss-automation]

Awesome work, congrats on your first merged pull request and thank you for helping improve everyone's experience!

[abhinavs1920]

Thanks for the careful review, and for adding the bound-method test to close out the codecov gaps. Enjoyed working through this one.