hapi-async-handler

Adds support for ES2017 async functions to hapi route handlers

ES7 Async Functions

ES7 introduces async functions, which are functions that support the await keyword and return promises. This hapi plugin adds a handler called async that allows you to write your route handlers using async functions. You can also use hapi-async-handler with Node.js, generator functions (and the yield keyword), and co today. There are examples of both styles of use shown below.

Using hapi-async-handler

Registering the Plugin

var server = new Hapi.Server();
server.register([
  require('hapi-async-handler'),
], (error) => { ... });

Defining a Route Handler

Define an async function that receives request and reply like a normal route handler and assign it the async property of the route handler.

server.route({
  method: 'GET',
  path: '/',
  handler: {
    // Define a property called "async" that's an async function
    async async(request, reply) {
      // instapromise gives you promises from methods with Node-style callbacks
      require('instapromise');
      let fileContents = await fs.promise.readFile('example.txt', 'utf8');
      reply(fileContents);
    },
  },
});

For the async keyword to work, you will need to transform your source code with Babel or a similar compiler.

Using co

You can also use co and generator functions without any source-code transformations:

server.route({
  method: 'GET',
  path: '/',
  handler: {
    // co.wrap creates a function that returns a promise, just like an async function
    async: co.wrap(function*(request, reply) {
      require('instapromise');
      var fileContents = yield fs.promise.readFile('example.txt', 'utf8');
      reply(fileContents);
    }),
  },
});