@aws-sdk/middleware-expect-continue

What is @aws-sdk/middleware-expect-continue?

@aws-sdk/middleware-expect-continue is a middleware package for the AWS SDK for JavaScript. It is used to handle the 'Expect: 100-continue' HTTP header, which allows a client to check if the server is willing to accept a request before actually sending the request body. This can be useful for optimizing network usage and improving performance when sending large payloads.

What are @aws-sdk/middleware-expect-continue's main functionalities?

Adding Expect-Continue Middleware

This feature allows you to add the Expect-Continue middleware to an AWS SDK client. The middleware is added to the client's middleware stack at the 'build' step with high priority.

const { S3Client } = require('@aws-sdk/client-s3');
const { expectContinueMiddleware } = require('@aws-sdk/middleware-expect-continue');

const client = new S3Client({});
client.middlewareStack.add(expectContinueMiddleware(), {
  step: 'build',
  priority: 'high',
});

Customizing Expect-Continue Middleware

This feature allows you to customize the Expect-Continue middleware by setting options such as the continue timeout. In this example, the continue timeout is set to 3000 milliseconds.

const { S3Client } = require('@aws-sdk/client-s3');
const { expectContinueMiddleware } = require('@aws-sdk/middleware-expect-continue');

const client = new S3Client({});
client.middlewareStack.add(expectContinueMiddleware({
  continueTimeout: 3000 // Custom timeout in milliseconds
}), {
  step: 'build',
  priority: 'high',
});

Other packages similar to @aws-sdk/middleware-expect-continue

axios

Axios is a popular HTTP client for Node.js and the browser. It supports the 'Expect: 100-continue' header through its configuration options. Compared to @aws-sdk/middleware-expect-continue, Axios is a more general-purpose HTTP client and can be used for a wide range of HTTP requests, not just those related to AWS services.

request

Request is another widely-used HTTP client for Node.js that supports the 'Expect: 100-continue' header. It provides a simple and easy-to-use API for making HTTP requests. While Request is more general-purpose, @aws-sdk/middleware-expect-continue is specifically designed to work with the AWS SDK for JavaScript.

README

@aws-sdk/middleware-expect-continue

Changelog

3.271.0 (2023-02-14)

Bug Fixes

• protocol-http: export field types (#4432) (b8320f4)

Features

• client-appconfig: AWS AppConfig now offers the option to set a version label on hosted configuration versions. Version labels allow you to identify specific hosted configuration versions based on an alternate versioning scheme that you define. (1ffdf34)
• client-datasync: With this launch, we are giving customers the ability to use older SMB protocol versions, enabling them to use DataSync to copy data to and from their legacy storage arrays. (125850c)
• client-ec2: With this release customers can turn host maintenance on or off when allocating or modifying a supported dedicated host. Host maintenance is turned on by default for supported hosts. (62c8b91)