(aws-lambda-nodejs): ICommandHooks requires all hooks to be implementated

Reproduction Steps

    new lambda.NodejsFunction(this, "LambdaFunction", {
      bundling: {
        commandHooks: {
          afterBundling(inputDir: string, outputDir: string): string[] {
            return [`echo "hello world"`];
          },
        },
      },
    });

What did you expect to happen?

For this to be valid, and the equivalent of defining no commands for beforeBundling and beforeInstall.

What actually happened?

Type '{ afterBundling(inputDir: string, outputDir: string): string[]; }' is missing the following properties from type 'ICommandHooks': beforeBundling, beforeInstall

Environment

• CDK CLI Version : 1.91.0
• Framework Version: 1.91.0
• Node.js Version: v14.15.1
• OS : macOS Catalina
• Language (Version): Typescript (4.2.3)

Other

Happy to provide a pull-request for this, looks very easy to fix. Unless I’m missing something we can just declare the functions as optional and then default them to the equivalent of () => [].

---

This is 🐛 Bug Report

[icj217]

Was able to figure out how to implement this in Python. The key step was creating an instance of the class and passing that into BundlingOptions

import typing
import builtins
import jsii
from aws_cdk import (
    aws_lambda_nodejs as njs,
)
​
@jsii.implements(njs.ICommandHooks)
class CustomCommandHooks:
​
    @jsii.member(jsii_name="afterBundling")
    def after_bundling(self, input_dir: builtins.str, output_dir: builtins.str) -> typing.List[builtins.str]:
        return []
​
    @jsii.member(jsii_name="beforeBundling")
    def before_bundling(self, input_dir: builtins.str, output_dir: builtins.str) -> typing.List[builtins.str]:
        return [f"cd {input_dir}", "yarn"]
​
    @jsii.member(jsii_name="beforeInstall")
    def before_install(self, input_dir: builtins.str, output_dir: builtins.str) -> typing.List[builtins.str]:
        return []

...


hooks = CustomCommandHooks()
​
options = njs.BundlingOptions(
        source_map=True,
        target="es2020",
        format=njs.OutputFormat.CJS,
        loader={".yaml": "file"},
        command_hooks=hooks)

@piotrekwitkowski FYI

[piotrekwitkowski]

A Python example how to use command_hooks would be greatly appreciated!