Ladybug Fetch

A Promise based HTTP(S) client library for NodeJS

Features

• Lightweight (no dependencies)
• Easy to use
• Full Promises support
• Chainable
• Auto handle compressed responses (gzip, deflate)
• Auto parse response body (json)
• Auto detect and set content type
• Instances for reducing duplicate calls with options
• Easy plugin support
• Lot of function overloads making it possible to use your style
• Use a custom promise library

Install

Note It is not in npm yet and is in early development, the way to install it is with github (see below), examples in this README may or may not work or is not ready, unstable or untested and the code design may change overtime if you would like to contribute Pull Requests and/or Issues are welcome.

npm install ladybug-fetch

Or the development version from the github repository

npm install freetnt5852/ladybug-fetch

You will need git installed and added to PATH for github installs

Examples

Basic Get (json)

const ladybug = require("ladybug-fetch");

ladybug("https://someapi.com/json")
  .json() // Short way to set content type, not really needed often if the url is meant to return json always
  .then((res) => console.log(res.body))
  .catch((err) => console.error(err));

Headers

ladybug("https://example.com")
  .set("Authorization", "Key")
  .set({
    "key": "value",
    "another": "foo"
  })
  .set("Authorization=foobar")
  .set(ladybug.bearer("foobar")) // helper function
  .then(console.log)
  .catch(console.error)

Querystrings

ladybug("https://example.com")
  .query({ limit: 5 })
  .query("key=value")
  .query("key", "value")
  .then((r) => console.log(r.body))
  .catch((e) => console.error(e));

Post Requests

ladybug.post("https://post.com")
  .send({ some: "json" })
  .set(ladybug.bearer(process.env.API_KEY))
  .then(console.log)
  .catch(console.error);

Similar way is possible with other methods ladybug.[get|post|put|patch|delete] with get being default if no method specified

Plugins

const ladybug = require("ladybug-fetch");

function plugin(req) {
 // do anything with the request object
 req.set("some-header", "value");
}

ladybug("https://example.com")
  .use(plugin)
  .then(console.log)
  .catch(console.error);

If you want options for your plugin export a function that returns a function

const ladybug = require("ladybug-fetch");

function plugin(options = {}) {
  return function(req) {
    if(options.something) req.doSomething();
  }
}

ladybug("https://example.com")
  .use(plugin({ ...options }))
  .then(console.log)
  .catch(console.error)

Global plugins

Plugins are per request by req.use however you can apply it globally for every request

const ladybug = require("ladybug-fetch");

function plugin(req) {
  req.set("key", "foobar");
}

ladybug.use(plugin);

ladybug("https://example.com")
  .then(console.log)
  .catch(console.error);

Async/Await

(async() => {

  const res = await ladybug("https://example.com")
    .set("key", "value")
    .query({ limit: 3 });

  console.log(res.body);

})();

Instances

Instances are powerful way to do many requests with lot of options instead of duplicating code

const ladybug = require("ladybug-fetch");

const api = ladybug.create({
  baseURL: "https://baseurl.com", // base url being used
  headers: { key: "value" }, // headers, can be overriden in the actual call
  method: "post", // default method to call if no method specified
  plugins: [plugin1, plugin2], // Array of plugins to be used by every request with tis instance
  query: { limit: 5 } // some default queries, can be overriden in the actual call
});

api("/endpoint") // POST -> https://baseurl.com/endpoint?limit=5
  .send({ json: "data" })
  .then(console.log)
  .catch(console.error);

Using a custom promise library

You can plug in a custom promise library easily for one or more requests

The first method is incase you are overriding the global Promise then nothing else is needed

global.Promise = require("bluebird");
// continue as normal

But if you want to use it without changing the global promise there are ways

For per requests use .promise()

ladybug("https://example.com")
  .promise(require("bluebird"))
  .then((res) => console.log(res.body));

ladybug("https://example.com", { promise: require("bluebird") })
  .then((res) => console.log(res.body));

The second way is to use it on an instance this makes it apply for every request on that instance only

const api = ladybug.create({ baseURL: "https://example.com" })
  .promise(require("bluebird"));
// or also pass it in the options object.

api("/route")
  .then((res) => console.log(res.body));

The third way is overriding the promise library for the global instance

const ladybug = require("ladybug");
ladybug.promise(require("bluebird"));

ladybug("https://example.com")
  .then((res) => console.log(res.body));
// All requests using global instance now uses that promise library
// This doesn't affect any other instances.

Status Codes

By default the library rejects the promise on 4xx and 5xx Errors but it is possible to override that behavior and validate status yourself using req.status()

ladybug("https://example.com")
  .status((s) => s < 500) // Anything below 500 is a success
  .then((res) => console.log(res.body));

As always all chainable methods are also available on instances to reduce duplications or even override the global instance

const ladybug = require("ladybug-fetch");

ladybug.status((s) => s < 500);

ladybug("https://example.com")
  .then((res) => console.log(res.body));

const api = ladybug.create({ baseURL: "https://example.com" })
  .status((s) => s < 500);

api("/route")
  .then((res) => console.log(res.body));

TODO

This library is still under early development and is not complete, Pull Requests are welcome if you want to contribute.

• Add support for following redirect codes.
• Form Data support
• A good test suite
• TypeScript typings

See also comments in code with TODO

License

MIT