Support dependency injection in lambda parameters

[RobinVds]

Is your feature request related to a problem? Please describe.
I'm injecting my dependencies in my lambda functions to be able to easily test my functions.

@logger.inject_lambda_context(log_event=True)
def lambda_handler(event,
                   context,
                   s3_client=s3,
                   sqs_queue=sqs_queue):

Describe the solution you'd like
Would it be possible to just allow more parameters in the decorator function than only event and context? Just pass all the parameters that are included in the lambda function call.

Describe alternatives you've considered
Not relying on dependency injection and testing one level lower.

Additional context
Not sure if this way of testing lambdas is a best practice but it makes it a lot easier that's for sure.

[boring-cyborg]

Thanks for opening your first issue here! We'll come back to you as soon as we can.

[heitorlessa]

Hey @RobinVds i merged that one today - it should be in the next release before the end of the year.

That said, there are better ways to test it - I often use dependency injection with ports and adapters so the handler becomes just an entry point.

I can post an example later and I've been meaning to update our quick start template to demonstrate how easy it becomes for unit and Integ test

[RobinVds]

Hey @RobinVds i merged that one today - it should be in the next release before the end of the year.

That said, there are better ways to test it - I often use dependency injection with ports and adapters so the handler becomes just an entry point.

I can post an example later and I've been meaning to update our quick start template to demonstrate how easy it becomes for unit and Integ test

Sounds interesting, looking forward to seeing how you implement that! 👍

[RobinVds]

@heitorlessa Would it be possible to post the example? Thanks!

[heitorlessa]

See if you have access to this: https://github.com/heitorlessa/aws-serverless-airline-booking/blob/refactor%2Floyalty-runtime/src/backend/loyalty/src/loyalty/aggregate/app.py#L17

• Storage Port: https://github.com/heitorlessa/aws-serverless-airline-booking/blob/refactor%2Floyalty-runtime/src/backend/loyalty/src/loyalty/shared/storage.py#L41
• Adapter for unit tests: https://github.com/heitorlessa/aws-serverless-airline-booking/blob/refactor%2Floyalty-runtime/src/backend/loyalty/src/loyalty/shared/storage.py#L55
• DynamoDB Adapter: https://github.com/heitorlessa/aws-serverless-airline-booking/blob/refactor%2Floyalty-runtime/src/backend/loyalty/src/loyalty/shared/storage.py#L88
• Unit tests using FakeStorage adapter: https://github.com/heitorlessa/aws-serverless-airline-booking/blob/refactor%2Floyalty-runtime/src/backend/loyalty/tests/unit/test_aggregate.py

I can provide more details tomorrow as I've been writing a doc for the past few days.

[RobinVds]

Thanks for the info! If you could, please ping me when you are finished with the doc :)

[heitorlessa]

hey @RobinVds this is available now in the 1.24 release (since Dec 31st tbh ;)). I've published the talk as a PDF covering that code snippet above - slide 46 and onward for the Ports & Adapters alone: https://www.slideshare.net/HeitorLessa1/aws-community-day-ireland-refactoring-a-serverless-app

Thanks a lot for raising that with us!

[github-actions]

This is now released under 1.25.10 version!