Override `highWaterMark` didn't work

Commencez au point d’entrée awslambda.streamifyResponse et suivez la manière dont son option highWaterMark et le symbole handler sont utilisés. Reproduisez les deux exemples et vérifiez qu’une valeur configurée de 512 fournit les écritures anticipées avant les écritures différées.

The following code will send the data BEFORE 6s:

const util = require('node:util');
const HANDLER_HIGHWATERMARK = Symbol.for(
  'aws.lambda.runtime.handler.streaming.highWaterMark',
);

const handler = async (event, responseStream, context) => {
        responseStream.setContentType('text/html; charset=utf-8');

        responseStream.write("Thinking...");
        responseStream.write("a".repeat(64 * 1024));

        setTimeout(function() {
            responseStream.write("b".repeat(64 * 1024));
        }, 3000);

        setTimeout(function() {
            responseStream.write("After 6s");
            responseStream.end();
        }, 6000);
    };

handler[HANDLER_HIGHWATERMARK] = 512;

exports.handler = awslambda.streamifyResponse(handler, {
        highWaterMark: 512
    }
);

The following code will only send data AFTER 6s.

const util = require('node:util');
const HANDLER_HIGHWATERMARK = Symbol.for(
  'aws.lambda.runtime.handler.streaming.highWaterMark',
);

const handler = async (event, responseStream, context) => {
        responseStream.setContentType('text/html; charset=utf-8');

        responseStream.write("Thinking...");
        responseStream.write("a".repeat(1 * 1024));

        setTimeout(function() {
            responseStream.write("b".repeat(1 * 1024));
        }, 3000);

        setTimeout(function() {
            responseStream.write("After 6s");
            responseStream.end();
        }, 6000);
    };

handler[HANDLER_HIGHWATERMARK] = 512;

exports.handler = awslambda.streamifyResponse(handler, {
        highWaterMark: 512
    }
);

From what I tested, the default highWaterMark is 64Kb, but there is no way to override it to be lower, I tried two different ways to do it.

This causes weird issues where I can't send some tiny text and then wait 6s to send more data, it will be sent as a single chunk only after 6s.

This issue was initially discovered at https://github.com/H4ad/serverless-adapter/issues/166