AWS.NodeHttpClient use undefined httpAgent instead of default one

[pivstone]

Describe the bug

when a user pass agent: undefined to a client (us DynamoDB as example).

import AWS from 'aws-sdk';
const options = {
    apiVersion: '2012-10-08',
    httpOptions: {
      agent: undefined
    },
  }
new AWS.DynamoDB.DocumentClient(options);

AWS.NodeHttpClient set a default agent in here.

aws-sdk-js/lib/http/node.js

Lines 35 to 39 in ffc003b

	if (!httpOptions.agent) {
	options.agent = this.getAgent(useSSL, {
	keepAlive: process.env[CONNECTION_REUSE_ENV_NAME] === '1' ? true : false
	});
	}

but the in the next line options.agent is updated to undefined by this line.

aws-sdk-js/lib/http/node.js

Line 41 in ffc003b

AWS.util.update(options, httpOptions);

Because the httpOptions.agent is undefined.

Expected Behavior

The http agent shouldn't be undefined.

Current Behavior

The http agent is undefined.

Reproduction Steps

as the description

Possible Solution

AWS.util.update(options, httpOptions);

should be executed before assign the default http agent instance.

A suggest fix: #4453

Additional Information/Context

No response

SDK version used

2.1374.0

Environment details (OS name and version, etc.)

Lambda/NodeJs 16

[RanVaknin]

Hi @pivstone ,

Thanks for the feedback and the PR, on a first glance it looks good.
We will review this and get back to you.

Thanks,
Ran~

[kuhe]

What is the scenario where you pass undefined to the agent?

[pivstone]

What is the scenario where you pass undefined to the agent?

We have an internal library dynamodb client for all our AWS Lambda, something like this.

type BaseOptions = {
  maxRetries?: number;
  timeoutMs?: number;
  httpsAgent?: httpsAgent;
};

function buildOption(options: BaseOptions) {
  return {
    apiVersion: '2012-10-08',
    convertEmptyValues: true,
    maxRetries: options.maxRetries ?? 3,
    httpOptions: {
      agent: options.httpsAgent ?? undefined,
      timeout: options.timeoutMs ?? 3000,
    },
  };
}

new AWS.DynamoDB.DocumentClient(buildOption(options));

we added the httpOptions. agent as the an optional parameter, because the sdk accept an undefined, so we think it's fine to use undefined as default value, then we found the latency of calling dynamodb increased from few ms to 22ms.

[RanVaknin]

PR merged. Closing.