feat(event_handler): define exception_handler directly from the router

[leandrodamascena]

Issue number: #1193

Summary

Changes

This pull request introduces a new feature allowing the direct definition of an exception_handler from the router. This enhancement is particularly beneficial for customers who are segmenting their routers into multiple files and including them in the Resolver.

User experience

split_route_module.py

from aws_lambda_powertools import Tracer
from aws_lambda_powertools.event_handler.api_gateway import Router, Response

tracer = Tracer()
router = Router()

endpoint = "https://jsonplaceholder.typicode.com/todos"


@router.get("/hello")
def get_todos():
    raise ValueError("ERROR")

@router.exception_handler(ValueError)
def handle_invalid_limit_qs(ex: ValueError):  # receives exception raised

    return Response(
        status_code=400,
        body="Invalid request parameters.",
    )

app.py

import split_route_module

from aws_lambda_powertools import Logger, Tracer
from aws_lambda_powertools.event_handler import APIGatewayRestResolver
from aws_lambda_powertools.logging import correlation_paths
from aws_lambda_powertools.utilities.typing import LambdaContext

tracer = Tracer()
logger = Logger()
app = APIGatewayRestResolver()


app.include_router(split_route_module.router)  

# You can continue to use other utilities just as before
@logger.inject_lambda_context(correlation_id_path=correlation_paths.API_GATEWAY_REST)
def lambda_handler(event: dict, context: LambdaContext) -> dict:
    return app.resolve(event, context)

Checklist

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• Meet tenets criteria
• I have performed a self-review of this change
• Changes have been tested
• Changes are documented
• PR title follows conventional commit semantics

Is this a breaking change?

RFC issue number:

Checklist:

• Migration process documented
• Implement warnings (if it can live side by side)

Acknowledgment

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Disclaimer: We value your time and bandwidth. As such, any pull requests created on non-triaged issues might not be successful.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarCloud

[codecov-commenter]

Codecov Report

❌ Patch coverage is 72.72727% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 96.30%. Comparing base (e14e768) to head (3ed9443).
⚠️ Report is 2545 commits behind head on develop.

Files with missing lines	Patch %	Lines
aws_lambda_powertools/event_handler/api_gateway.py	72.72%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #3979      +/-   ##
===========================================
- Coverage    96.38%   96.30%   -0.08%     
===========================================
  Files          214      215       +1     
  Lines        10030    10262     +232     
  Branches      1846     1915      +69     
===========================================
+ Hits          9667     9883     +216     
- Misses         259      271      +12     
- Partials       104      108       +4     

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[rubenfonseca]

Reviewing now

[rubenfonseca]

Nice and clean, loved it!

[alecrevangelista]

Cool! @leandrodamascena // @rubenfonseca which release version will this be a part of?