aws-cdk-lib(core): ILocalBundling is missing access to asset source path

[fbenkstein]

Describe the bug

When a ILocalBundling's tryBundle is called there is no way to find out the asset's source path from within the function. The tryBundle function only receives the output dir and the bundling options:

export interface ILocalBundling {
  /**
   * This method is called before attempting docker bundling to allow the
   * bundler to be executed locally. If the local bundler exists, and bundling
   * was performed locally, return `true`. Otherwise, return `false`.
   *
   * @param outputDir the directory where the bundled asset should be output
   * @param options bundling options for this asset
   */
  tryBundle(outputDir: string, options: BundlingOptions): boolean;
}

I was able to work around this problem by passing the asset path to my classes constructur but I don't think that is the intended way to call it (pardon the Python - I am not very versed in TypeScript):

@jsii.implements(ILocalBundling)
class MyLocalBundling:
  def __init__(self, *, asset_path):
      self.asset_path = asset_path

  def try_bundle(self, output_dir, *, bundling_options):
    # TODO: put self.asset_path into output_dir somehow
    pass

class MyStack(Stack):
  def add_my_asset(self):
    my_asset_path = my_get_asset_path()
    asset = Asset(
        self,
        "MyAsset",
        path=my_asset_path,
        bundling=BundlingOptions(
           local=MyLocalBundling(asset_path=asset_path),
           # other options, like docker image etc. go here
           ...
        )
    )

This is needlessly complicated (because I have to create a local variable for the asset path) and potentially error-prone (I might pass the wrong asset path to the bundler). If this is indeed the intended behaviour I wish this was called out in the documentation.

I suggest extending the ILocalBundling interface with an additional, optional method:

  /**
   * This method is called before attempting docker bundling to allow the
   * bundler to be executed locally. If the local bundler exists, and bundling
   * was performed locally, return `true`. Otherwise, return `false`.
   *
   * @param assetPath the path where the input asset is found
   * @param outputDir the directory where the bundled asset should be output
   * @param options bundling options for this asset
   */
  tryBundleAsset?(assetPath: string, outputDir: string, options: BundlingOptions): boolean;

The asset staging logic could try to call tryBundleAsset if it exists and if not fall back to tryBundle.

Expected Behavior

The asset path should be a parameter to the tryBundle method of a ILocalBundling

Current Behavior

An ILocalBundling has no way of knowing the asset path unless it's passed in the constructure or through a closure.

Reproduction Steps

See above.

Possible Solution

See above.

Additional Information/Context

No response

CDK CLI Version

2.55.0 (build 077d77d)

Framework Version

No response

Node.js Version

v14.21.1

OS

Linux

Language

Typescript, Python

Language Version

Python 3.8

Other information

No response

[peterwoodworth]

If you have an idea on how to implement this, a PR would be a great jump start for this

[gscpw]

This is still a problem; it is a significant usability oversight.