Export core explicitly in package.json

[shishkin]

I think the suggested solution to use the default export is not satisfactory. I'm running into issues when bundlers scan dependencies and choke on things inside the aws-cdk-lib that I don't even use (e.g. Dockerfile from aws-cdk-lib/lambda-layer-kubectl/layer/Dockerfile 🤷‍♂️ ), but they're still reachable from the bundler's perspective because my code imports aws-cdk-lib default export which exports everything.

Exporting core explicitly would allow for better tree shaking in bundlers. Otherwise aws-cdk-lib objectively still remains a monolithic CJS package and neglects benefits of ESM.

Originally posted by @shishkin in #17950 (comment)

[peterwoodworth]

We cannot change this until the next major version without it being a breaking change, so I think you'll need to find some sort of workaround for your problem. I'm converting this to a discussion for better longevity and searchability on the issue 🙂

[shishkin]

For anyone facing the same issue, I found a workaround by structuring exports of my package. I made sure that code importing CDK lib is exported via a separate export in package.json and is not imported anywhere from the main index.ts export.

[xChickens]

I don't understand - why would this be a breaking change? Why would adding a line for "./core" pointing to "./core/index.js" break things? The root (".") still points to "./index.js" so people would still be able to use the default export.

[xChickens]

@peterwoodworth