aws-lambda-nodejs: charset props not work

[intptr-t]

Describe the bug

When building TypeScript/JavaScript with aws-lambda-nodejs, the parameter (Charset.UTF8) that does not escape non-ASCII characters does not work.

Regression Issue

• Select this option if this issue appears to be a regression.

Last Known Working CDK Version

v2.85.0

Expected Behavior

If UTF8 is specified for charset, --charset=utf8 is passed to esbuild so that characters are output without escaping.

example expected output

// package/example.ts
var handler = async () => {
  console.log("Japanese:日本語");
};
export {
  handler
};

Current Behavior

Even if UTF8 parameters are passed, escaped strings are always output.

example current output

// package/example.ts
var handler = async () => {
  console.log("Japanese:\u65E5\u672C\u8A9E");
};
export {
  handler
};

Reproduction Steps

Restores the process of setting the deleted charset.

      ...this.props.banner ? [`--banner:js=${JSON.stringify(this.props.banner)}`] : [],
      ...this.props.footer ? [`--footer:js=${JSON.stringify(this.props.footer)}`] : [],
+      ...this.props.charset ? [`--charset=${this.props.charset}`] : [],
      ...this.props.mainFields ? [`--main-fields=${this.props.mainFields.join(',')}`] : [],

https://github.com/aws/aws-cdk/blob/v2.173.2/packages/aws-cdk-lib/aws-lambda-nodejs/lib/bundling.ts#L260-L262

Possible Solution

No response

Additional Information/Context

The following commit confirms that it has been removed.
3f1f974
file: packages/aws-cdk-lib/aws-lambda-nodejs/lib/bundling.ts

CDK CLI Version

2.173.2

Framework Version

No response

Node.js Version

v22.11.0

OS

macOS

Language

TypeScript

Language Version

No response

Other information

Example stack code

export class TestStack extends cdk.Stack {
  constructor(scope: Construct, id: string, props?: cdk.StackProps) {
    super(scope, id, props);

    new NodejsFunction(this, "Test", {
      entry: "example.ts",
      handler: "index.handler",
      runtime: Runtime.NODEJS_22_X,
      bundling: {
        format: OutputFormat.ESM,
        charset: Charset.UTF8, // <-- This property is not work
      },
    });
  }
}

[ashishdhingra]

@intptr-t Good afternoon. Thanks for opening the issue. You confirmed that the option for was removed it commit 3f1f974 via PR #25859. We are unsure if the ...this.props.charset ? [--charset=${this.props.charset}] : [] was meant to be removed in that PR via commit 3f1f974 (the charset option was added way back in 2021 via 56033a2). Marking this is p1 since it's been whole year. I have communicated this issue to the team.

Thanks,
Ashish