Feature request: Provide idempotency at function level (via wrapper function and decorator) (FR2)

[ijemmy]

Description of the feature request

Problem statement
Library users want to add idempotency attribute to the Lambda handler.

Check the design spec for details.

Summary of the feature

• Provide two interface (wrapper function and decorator) to make a Lambda idempotent
• Cover edge cases described in the design spec
• Provide a DynamoDB persistent layer for keeping idempotency records
• Provide a base class for persistent layer. Library users can extend to make implementation on different storage.

Code examples
See the design spec

Story Checklist (for tracking progress)

• As a developer, I would like to implement the Dynamo persistence layer
  • Dynamo specific interaction definitions
• As a developer, I would like to implement the persistence base layer
  • Base class that will handle creating the hash, expiry date, and orchestration to the implementing subclass persistence layer
• As a developer, I would like to implement the idempotency handler/wrapper
  • Defines core idempotency logic: saving in progress records conditionally, calling the function that is being made idempotent via a wrapper/decorator, updating idempotency records when complete, deleting idempotency records in case of error
• Check if we can remove the unknown type (See comment https://github.com/awslabs/aws-lambda-powertools-typescript/pull/1110/files/0ec830102bce74a6e423cb29dc102ca47f8fc1fe#r1009618833)

Definition of done

• Include unit tests with 100% code coverage
• Code documentation (TS doc) on classes and public methods

Related issues, RFCs

#447

[ijemmy]

@jeffrey-baker-vg FYI.

Let's use this issue for tracking progress and links to PR.

[ijemmy]

@jeffrey-baker-vg @vgphoenixcampos

[saragerion]

Closing this issue as we will break down the unit of work different ones.