Feature request: build as esmodule

[flochaz]

Description of the feature request

Problem statement
Powertools is packaged as commonJS which does not give the capability to javascript developers to use esmodule import syntax and feature.

Summary of the feature
Now that AWS Lambda support es module import it might worth generating esmodule.

Code examples

Before:

const { Tracer } = require('@aws-lambda-powertools/tracer');

After:

import { Tracer } from '@aws-lambda-powertools/tracer';

Benefits for you and the wider AWS community
See https://aws.amazon.com/blogs/compute/using-node-js-es-modules-and-top-level-await-in-aws-lambda/ for more details ...

Additional context
slack channel discussion

Related issues, RFCs

#490

[saragerion]

Thanks @flochaz for opening this issue! If I look at the AWS SDK v3, this is how @trivikr and the team handles it:

1. They transpile the TS code three times, once for CommonJS, once for ES6 and once for the types. To achieve this, they use 2 tsconfig files: tsconfig.cjs and tsconfig.es.
2. In their docs, they use both import styles in their examples: https://github.com/aws/aws-sdk-js-v3/tree/cc17fa2296654192d2a9c2cf567d2ce58d81d15b/lib/lib-dynamodb#constructor.

Full example for the DynamoDB client:
https://github.com/aws/aws-sdk-js-v3/tree/cc17fa2296654192d2a9c2cf567d2ce58d81d15b/lib/lib-dynamodb

---

Personally, I think that right now supporting both CommonJS and ES6 is not a high priority, but a nice to have that would definitely improve the dev experience. I would like to see a small proof of concept but I don't think this is something we should prioritize for the production ready milestone.
(Maybe some folks from our community can help out in the future?)

[dreamorosi]

If we want, at least for now, make sure that the three core utilities available (Logger, Metrics, and Tracer) all advance at the same pace, the main dependency for Tracer (aws-xray-sdk-node) constitutes a major blocker for this effort as it currently doesn't support ESM bundling.

Given that our main focus at the moment is to bring these utils to a production ready status. Marking this issue as blocked and on-hold till further notice.