feat(idempotency): support dataclasses & pydantic models payloads

[michaelbrewer]

Issue #, if available:

Description of changes:

Add support for serialization of python dataclasses, but checking if __dataclass_fields__ exists and calling dataclasses.asdict. This happens early on in the idempotency work flow.

UX

Dataclasses support

from dataclasses import dataclass

from aws_lambda_powertools.utilities.idempotency import (
    DynamoDBPersistenceLayer, IdempotencyConfig, idempotent_function)

dynamodb = DynamoDBPersistenceLayer(table_name="idem")
config =  IdempotencyConfig(
    event_key_jmespath="order_id",  # extract and hash this field only as the idempotency key
    use_local_cache=True,
)

@dataclass
class OrderItem:
    sku: str
    description: str

@dataclass
class Order:
    item: OrderItem
    order_id: int


@idempotent_function(data_keyword_argument="order", config=config, persistence_store=dynamodb)
def process_order(order: Order):
    return f"processed order {order.order_id}"


order_item = OrderItem(sku="fake", description="sample")
order = Order(item=order_item, order_id="fake-id")

# `order` parameter must be called as a keyword argument to work
process_order(order=order)

Pydantic support

from aws_lambda_powertools.utilities.idempotency import (
    DynamoDBPersistenceLayer, IdempotencyConfig, idempotent_function)
from aws_lambda_powertools.utilities.parser import BaseModel

dynamodb = DynamoDBPersistenceLayer(table_name="idem")
config =  IdempotencyConfig(
    event_key_jmespath="order_id",  # extract and hash this field only as the idempotency key
    use_local_cache=True,
)


class OrderItem(BaseModel):
    sku: str
    description: str


class Order(BaseModel):
    item: OrderItem
    order_id: int


@idempotent_function(data_keyword_argument="order", config=config, persistence_store=dynamodb)
def process_order(order: Order):
    return f"processed order {order.order_id}"


order_item = OrderItem(sku="fake", description="sample")
order = Order(item=order_item, order_id="fake-id")

# `order` parameter must be called as a keyword argument to work
process_order(order=order)

Checklist

• Meet tenets criteria
• Update tests
• Update docs
• PR title follows conventional commit semantics

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

[codecov-commenter]

Codecov Report

Merging #908 (4f08bab) into develop (9abeb32) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff            @@
##           develop     #908   +/-   ##
========================================
  Coverage    99.88%   99.88%           
========================================
  Files          118      118           
  Lines         5261     5272   +11     
  Branches       602      605    +3     
========================================
+ Hits          5255     5266   +11     
  Misses           2        2           
  Partials         4        4           

Impacted Files	Coverage Δ
...wertools/utilities/idempotency/persistence/base.py	99.36% <ø> (-0.01%)	⬇️
...ws_lambda_powertools/utilities/idempotency/base.py	100.00% <100.00%> (ø)
aws_lambda_powertools/tracing/tracer.py	100.00% <0.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 9abeb32...4f08bab. Read the comment docs.

[heitorlessa]

🤦 my comments were kept in pending... only one ask really - could you add a test with event_jmespath to use a given field of a dataclass?