popsicle

What is popsicle?

Popsicle is a versatile HTTP request library for Node.js and the browser. It provides a simple and consistent API for making HTTP requests, handling responses, and managing various aspects of HTTP communication such as headers, query parameters, and request/response bodies.

What are popsicle's main functionalities?

Making HTTP Requests

This feature allows you to make HTTP requests to a specified URL. The example demonstrates a GET request to a JSON placeholder API, logging the status and body of the response.

const { request } = require('popsicle');

request('https://jsonplaceholder.typicode.com/posts/1')
  .then(response => {
    console.log(response.status);
    console.log(response.body);
  })
  .catch(error => {
    console.error(error);
  });

Handling Query Parameters

This feature allows you to include query parameters in your HTTP requests. The example demonstrates a GET request with a query parameter to filter posts by userId.

const { request } = require('popsicle');

request({
  url: 'https://jsonplaceholder.typicode.com/posts',
  query: { userId: 1 }
})
  .then(response => {
    console.log(response.status);
    console.log(response.body);
  })
  .catch(error => {
    console.error(error);
  });

Setting Headers

This feature allows you to set custom headers for your HTTP requests. The example demonstrates setting the 'Content-Type' header to 'application/json'.

const { request } = require('popsicle');

request({
  url: 'https://jsonplaceholder.typicode.com/posts',
  headers: { 'Content-Type': 'application/json' }
})
  .then(response => {
    console.log(response.status);
    console.log(response.body);
  })
  .catch(error => {
    console.error(error);
  });

Handling Request and Response Bodies

This feature allows you to handle request and response bodies. The example demonstrates a POST request with a JSON body to create a new post.

const { request } = require('popsicle');

request({
  method: 'POST',
  url: 'https://jsonplaceholder.typicode.com/posts',
  body: { title: 'foo', body: 'bar', userId: 1 },
  headers: { 'Content-Type': 'application/json' }
})
  .then(response => {
    console.log(response.status);
    console.log(response.body);
  })
  .catch(error => {
    console.error(error);
  });

Other packages similar to popsicle

axios

Axios is a popular promise-based HTTP client for the browser and Node.js. It provides a simple API for making HTTP requests and handling responses, similar to Popsicle. Axios is known for its ease of use and wide adoption in the JavaScript community.

node-fetch

Node-fetch is a lightweight module that brings `window.fetch` to Node.js. It is a minimalistic library that provides a simple API for making HTTP requests, similar to the Fetch API in the browser. Node-fetch is often used for its simplicity and compatibility with the Fetch API standard.

superagent

Superagent is a small progressive client-side HTTP request library, and Node.js module with a similar API. It provides a flexible and powerful API for making HTTP requests and handling responses. Superagent is known for its extensive feature set and ease of use.

README

Popsicle is the easiest way to make HTTP requests - offering a consistent, intuitive and light-weight API that works on node and the browser.

popsicle.get('/users.json')
  .then(function (res) {
    console.log(res.status) //=> 200
    console.log(res.body) //=> { ... }
    console.log(res.headers) //=> { ... }
  })

Installation

npm install popsicle --save

Usage

var popsicle = require('popsicle')
// var popsicle = window.popsicle

popsicle.default({
  method: 'POST',
  url: 'http://example.com/api/users',
  body: {
    username: 'blakeembrey',
    password: 'hunter2'
  },
  headers: {
    'Content-Type': 'application/x-www-form-urlencoded'
  }
})
  .then(function (res) {
    console.log(res.status) // => 200
    console.log(res.body) //=> { ... }
    console.log(res.get('Content-Type')) //=> 'application/json'
  })

Popsicle is ES6-ready, aliasing default to the default export. Try using import popsicle from 'popsicle' or import specific methods using import { get, defaults } from 'popsicle'.

Handling Requests

• url The resource location
• method The HTTP request method (default: "GET")
• headers An object with HTTP headers, header name to value (default: {})
• query An object or string to be appended to the URL as the query string
• body An object, string, form data, stream (node), etc to pass with the request
• timeout The number of milliseconds to wait before aborting the request (default: Infinity)
• use An array of plugins to be used (default: see below)
• options Raw options used by the transport layer (default: {})
• transport Override the transportation layer (default: http.request/https.request (node), XMLHttpRequest (brower))

Options using node transport

The default plugins under node are [stringify(), headers(), unzip(), concatStream('string'), parse()].

• jar An instance of a cookie jar (popsicle.jar()) (default: null)
• agent Custom HTTP pooling agent (default: infinity-agent)
• maxRedirects Override the number of redirects allowed (default: 5)
• rejectUnauthorized Reject invalid SSL certificates (default: true)
• followRedirects Disable redirects or use a function to accept 307/308 redirects (default: true)

Options using browser transport

The default plugins in the browser are [stringify(), headers(), parse()]. Notice that unzipping and various stream parsing is not yet available in browsers.

• withCredentials Send cookies with CORS requests (default: false)
• responseType Set the XHR responseType (default: undefined)

P.S.: Need a proxy? Try using proxy-agent with the agent option.

Short-hand Methods

Common methods have a short hand exported (created using defaults({ method: 'get' })).

popsicle.get('http://example.com/api/users')
popsicle.post('http://example.com/api/users')
popsicle.put('http://example.com/api/users')
popsicle.patch('http://example.com/api/users')
popsicle.del('http://example.com/api/users')

Extending with Defaults

Create a new request function with defaults pre-populated. Handy for a common cookie jar or transport to be used.

var cookiePopsicle = popsicle.defaults({ options: { jar: popsicle.jar() } })

Automatically Stringify Request Body

Popsicle can automatically serialize the request body using the built-in stringify plugin. If an object is supplied, it will automatically be stringified as JSON unless the Content-Type was set otherwise. If the Content-Type is multipart/form-data or application/x-www-form-urlencoded, it will be automatically serialized.

popsicle.get({
  url: 'http://example.com/api/users',
  body: {
    username: 'blakeembrey'
  },
  headers: {
    'Content-Type': 'application/x-www-form-urlencoded'
  }
})

Multipart Request Bodies

You can manually create form data by calling popsicle.form. When you pass a form data instance as the body, it'll automatically set the correct Content-Type - complete with boundary.

var form = popsicle.form({
  username: 'blakeembrey',
  profileImage: fs.createReadStream('image.png')
})

popsicle.post({
  url: '/users',
  body: form
})

Aborting Requests

All requests can be aborted before or during execution by calling Request#abort.

var request = popsicle.get('http://example.com')

setTimeout(function () {
  request.abort()
}, 100)

request.catch(function (err) {
  console.log(err) //=> { message: 'Request aborted', code: 'EABORTED' }
})

Progress

The request object can be used to check progress at any time.

• request.uploadedBytes Current upload size in bytes
• request.uploadLength Total upload size in bytes
• request.uploaded Total uploaded as a percentage
• request.downloadedBytes Current download size in bytes
• request.downloadLength Total download size in bytes
• request.downloaded Total downloaded as a percentage
• request.completed Total uploaded and downloaded as a percentage

All percentage properties (request.uploaded, request.downloaded, request.completed) are a number between 0 and 1. Aborting the request will emit a progress event, if the request had started.

var request = popsicle.get('http://example.com')

request.uploaded //=> 0
request.downloaded //=> 0

request.progress(function () {
  console.log(request) //=> { uploaded: 1, downloaded: 0, completed: 0.5, aborted: false }
})

request.then(function (response) {
  console.log(request.downloaded) //=> 1
})

Default Plugins

The default plugins are exposed under popsicle.plugins, which allows you to mix, match and omit some plugins for maximum usability with any use-case.

{
  headers: [Function: headers],
  stringify: [Function: stringify],
  parse: [Function: parse],
  cookieJar: [Function: cookieJar],
  unzip: [Function: unzip],
  concatStream: [Function: concatStream],
  defaults: [
    [Function: stringify],
    [Function: headers],
    [Function: cookieJar],
    [Function: unzip],
    [Function: concatStream],
    [Function: parse]
  ]
}

• headers Sets default headers, such as User-Agent, Accept, Content-Length (Highly recommended)
• stringify Stringify object bodies into JSON/form data/url encoding (Recommended)
• parse Automatically parse JSON and url encoding responses
• unzip Automatically unzip response streams (Node only)
• concatStream Buffer the whole stream using concat-stream - accepts an "encoding" type (string (default), buffer, array, uint8array, object) (Node only)
• cookieJar Support the cookie jar option in node (Recommended, Node only)

Cookie Jar (Node only)

You can create a reusable cookie jar instance for requests by calling popsicle.jar.

var jar = request.jar()

popsicle.default({
  method: 'POST',
  url: '/users',
  options: {
    jar: jar
  }
})

Handling Responses

Promises and node-style callbacks are both supported.

Promises

Promises are the most expressive interface. Just chain using Request#then or Request#catch and continue.

popsicle.get('/users')
  .then(function (res) {
    // Success!
  })
  .catch(function (err) {
    // Something broke.
  })

If you live on the edge, try using it with generators (see co) or ES7's async.

co(function * () {
  yield popsicle.get('/users')
})

Callbacks

For tooling that still expects node-style callbacks, you can use Request#exec. This accepts a single function to call when the response is complete.

popsicle.get('/users')
  .exec(function (err, res) {
    if (err) {
      // Something broke.
    }

    // Success!
  })

Response Objects

Every Popsicle response will give a Response object on success. The object provides an intuitive interface for requesting common properties.

• status The HTTP response status code
• body An object (if parsed using a plugin) or string that was the response HTTP body
• headers An object of lower-cased keys to header values
• url The response URL after redirects (only supported in browser with responseURL)
• statusType() Return an integer with the HTTP status type (E.g. 200 -> 2)
• get(key) Retrieve a HTTP header using a case-insensitive key
• name(key) Retrieve the original HTTP header name using a case-insensitive key
• type() Return the response type (E.g. application/json)

Error Handling

All response handling methods can return an error. Errors have a popsicle property set to the request object and a code string. The built-in codes are documented below, but custom errors can be created using request.error(message, code, cause).

• EABORT Request has been aborted by user
• EUNAVAILABLE Unable to connect to the remote URL
• EINVALID Request URL is invalid
• ETIMEOUT Request has exceeded the allowed timeout
• ESTRINGIFY Request body threw an error during stringification plugin
• EPARSE Response body threw an error during parsing plugin
• EMAXREDIRECTS Maximum number of redirects exceeded (Node only)
• EBODY Unable to handle request body (Node only)
• EBLOCKED The request was blocked (HTTPS -> HTTP) (Browsers only)
• ECSP Request violates the documents Content Security Policy (Browsers only)

Plugins

Plugins can be passed in as an array with the initial options (which overrides default plugins), or they can be used via the chained method Request#use.

External Plugins

• Server - Automatically mount a server on an available for the request (helpful for testing a la supertest)
• Status - Reject responses on HTTP failure status codes
• Cache - Built-in cache handling of HTTP requests under node (customizable store, uses a filesystem store by default)
• No Cache - Prevent caching of HTTP requests in browsers
• Basic Auth - Add a basic authentication header to each request
• Prefix - Prefix all HTTP requests
• Resolve - Resolve all HTTP requests against a base URL
• Constants - Replace constants in the URL string
• Limit - Transparently handle API rate limits by grouping requests
• Group - Group requests and perform operations on them all at once

Creating Plugins

Plugins must be a function that accepts configuration and returns another function. For example, here's a basic URL prefix plugin.

function prefix (url) {
  return function (request) {
    request.url = url + req.url
  }
}

popsicle.default('/user')
  .use(prefix('http://example.com'))
  .then(function (response) {
    console.log(response.url) //=> "http://example.com/user"
  })

Popsicle also has a way modify the request and response lifecycle, if needed. Any registered function can return a promise to defer the request or response resolution. This makes plugins such as rate-limiting and response body concatenation possible.

• before(fn) Register a function to run before the request is made
• after(fn) Register a function to receive the response object
• always(fn) Register a function that always runs on resolve or reject

Checking The Environment

popsicle.browser //=> true

Transportation Layers

Creating a custom transportation layer is just a matter creating an object with open, abort and use options set. The open method should set any request information required between called as request.raw. Abort must abort the current request instance, while open must always resolve the promise. You can set use to an empty array if no plugins should be used by default. However, it's recommended you keep use set to the defaults, or as close as possible using your transport layer.

TypeScript

This project is written using TypeScript and typings. From version 1.3.1, you can install the type definition using typings.

typings install npm:popsicle --name popsicle

Development

Install dependencies and run the test runners (node and Electron using Tape).

npm install && npm test

Related Projects

• Superagent - HTTP requests for node and browsers
• Fetch - Browser polyfill for promise-based HTTP requests
• Axios - HTTP request API based on Angular's $http service

License

MIT