feat(lambda-nodejs) experimental decorators support

[whimzyLive]

Desciption

esBuild doesn't support emitting typescript metadata which break workflow of many popular libraries that relies on such runtime metadata information. i.e Nestjs, TypeORM. TypeDORM.
Since this is an experimental feature, ESBuild doen't have any immidiate plan to support it.

Typescript's default tsc compiler does support this and other experimental features. Therefore, This PR adds support for typescript's experimental features by optionally executing tsc on the soruces before passing it through to esBuild for bundling.

For more information, look at the issue #13767

Tasks

• initial experimental features support
• update public apis to include new properties
• ensure bundling happens within the asset bundling-temp-x locations
• update docker bundling to optionally install typescript as the same version used by host (currently always installs typescript@latest)
• add test coverage for both local and docker bundling
• update readme with usage

closes #13767

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By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license

[gitpod-io]

[mergify]

Title does not follow the guidelines of Conventional Commits. Please adjust title before merge.

[aws-cdk-automation]

AWS CodeBuild CI Report

• CodeBuild project: AutoBuildProject89A8053A-LhjRyN9kxr8o
• Commit ID: 565df81
• Result: FAILED
• Build Logs (available for 30 days)

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[whimzyLive]

This is basically everything that I think is needed to support tsc -> esbuild workflow, but there are some changes that are required in order for it to work correctly with the assets caching/staging logic. I will look into it a bit more next weekend, meanwhile if anyone is looking for a quick patch, @ me here, and I will send over the patch file, or you can extract it directly from the changes above.

[jogold]

@whimzyLive thank you for this PR. I will have more time to review it in August (or maybe someone from the CDK team will review it before).

Question: when working with the AWS CDK in TypeScript you usually have a tsc step that runs during your build (locally and in CI) and it compiles your Lambda handlers files. If you specify the resulting .js file as entry for your NodejsFunction then you already have a working solution/workaround?

[whimzyLive]

@jogold No worries, I still have some work to do around the assets' temp-bundling is managed so August is fine.

Question: when working with the AWS CDK in TypeScript you usually have a tsc step that runs during your build (locally and in CI) and it compiles your Lambda handlers files. If you specify the resulting .js file as an entry for your NodejsFunction then you already have a working solution/workaround?

The answer to this question is Yes and No.

In a normal dev workflow, this is statement stands corrected but we are working with a monorepo consisting of many CDK/Ts apps and because of many unrelated issues (i.e slowness), we have decided to completely remove the ts -> js compilation step from all dev steps (and let the tools do it implicitly). Speaking of which, for testing, we use ts-jest preset; for local running/debugging, there is ts-node (to transpile to js on the fly, in memory), and we use NodejsFunctions to take care of compiling, bundling, and minifying, which worked really well until recently, when NodejsFunction was updated to use esBuild instead of the parcel. So basically these changes allow us to continue offloading compiling responsibilities to NodejsFunction and we can continue working in the same manner we used to. Hope this makes sense, and also sorry for the long answer but I didn't know how to explain otherwise. 🙂️

[TheRealAmazonKendra]

This PR has been deemed to be abandoned, and will be closed. Please create a new PR for these changes if you think this decision has been made in error.

[meg2208]

Just want to confirm... lambda-nodejs does not support decorators, right? So if I'm using a library that uses them like typedi or typeorm, then would it be best to use a docker image?