feat(validation): support JSON Schema referencing in validation utils

[danieljnchen]

Issue number: #4499

Summary

Changes

Please provide a summary of what's being changed

This change updates aws-lambda-powertools' validation functions to support passing the handlers param to fastjsonschema's validate call.

Customers now can use this new parameter

from aws_lambda_powertools.utilities.validation import validate, validator

PARENT_SCHEMA = {
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://example.com/schemas/parent.json",
  "type": "object",
  "properties": {
    "ParentSchema": {
      "$ref": "https://SCHEMA"
    }
  }
}

CHILD_SCHEMA = {
  "$schema": "http://json-schema.org/draft-07/schema#",
  "$id": "https://example.com/schemas/child.json",
  "type": "object",
  "properties": {
    "project": {
      "type": "string"
    }
  },
  "required": ["project"]
}

def get_child_schema(uri):
    return CHILD_SCHEMA

@validator(inbound_schema=PARENT_SCHEMA,inbound_handlers={"https": get_child_schema})
def lambda_handler(event, context):
    return "OK"

User experience

Please share what the user experience looks like before and after this change

Users previously were unable to use schemas with JSON Schema references

Checklist

If your change doesn't seem to apply, please leave them unchecked.

• 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

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

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

[boring-cyborg]

Thanks a lot for your first contribution! Please check out our contributing guidelines and don't hesitate to ask whatever you need.
In the meantime, check out the #python channel on our Powertools for AWS Lambda Discord: Invite link

[leandrodamascena]

Hello @danieljnchen! Thans a lot for this super quick and very useful PR! We really need to offer this support to our customers.
I left a comment before I started doing a more detailed review.

Thank you and please ping me if you have any difficulties and I can help.

[sonarqubecloud]

Quality Gate failed

Failed conditions
2 Security Hotspots

See analysis details on SonarCloud

[danieljnchen]

Alright, my development environment is all set up, and I've run the make pr step. The only check that's failing is the complexity check that I left a note about. Let me know if I need to make any more changes to get this ready to go in!

[leandrodamascena]

Alright, my development environment is all set up, and I've run the make pr step. The only check that's failing is the complexity check that I left a note about. Let me know if I need to make any more changes to get this ready to go in!

Hi @danieljnchen! This is amazing! I'm reviewing this PR and if I find something small and easy to fix, I'll push some commits to get it merged quickly!

Thank you very much for taking the time to make this improvement!

[danieljnchen]

Hey @danieljnchen! I've made some minor changes to this PR, let me explain them:

1 - To reduce the cyclomatic complexity, I created a new function, and now we are testing if variables are None or not through this function. This approach allows us to avoid direct if statements in the specific code, thereby reducing complexity and making Xenon happy.

2 - I refactored the example to make it more clear for customers that want just to copy and past and test this in their Lambda functions.

This PR is happily approved ❤️ .

@leandrodamascena (and @heitorlessa) thanks for your help getting this PR all cleaned up! I'm really excited to see this go in -- this is my first time contributing to an open-source project (I tried with python-dateutil a while back, but my MR never got reviewed). I appreciate the responsiveness and encouragement!

[heitorlessa]

This is looking GREAT!!!

Made final comments, one potential error on exceptions, a small refactoring, line editing for docs along with explanation as to why each of them.

Looking forward to this - thank you both!!

[boring-cyborg]

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