Koa-respond NPM

koa-respond

Middleware for Koa that adds useful methods to the Koa context.

Installation

npm install --save koa-respond

Usage

// Install it
const respond = require('koa-respond');

// For Koa v2 - if you are looking for v1, scroll to the bottom.
app.use(respond());

// Use it
app.use((ctx) => {
  // Sets status to 200 and the body to `{ id: 123, name: 'Dat Boi' }`
  ctx.ok({ id: 123, name: 'Dat Boi' });

  // Both of these set status to 404 and
  // the body to `{ message: 'Not found, boii' }`
  ctx.notFound('Not found, boii');
  ctx.notFound({ message: 'Not found, boii' });

  // And everyone's favorite..
  ctx.badRequest({ error: 'missing input' });

  // Or if you prefer to do it yourself..
  // Both of these send a HTTP 201 with a body
  // of `{ message: 'new beginnings!' }`
  ctx.send(201, 'new beginnings!');
  ctx.send(201, { message: 'new beginnings!' });
});

Methods

All methods call the send method with the corresponding status code as well as the body. That means they support the same overloads as send:

With a string; wraps it in an object with a message property. That means the following 2 calls do the same thing:
```
ctx.send(400, 'lol no');
ctx.send(400, { message: 'lol no' });
```

With an object; sends the object as JSON.

ctx.send(200, { id: 123, name: 'new entity' });

If you wish to disable the automatic wrapping of strings globally, you can instantiate koa-respond with autoMessage: false.

app.use(respond({
  autoMessage: false
}))

All functions return the Koa context itself (chainable)

ctx.ok().set({ 'X-Some-Header': 'awesome' })

All functions are also bound to the context. This means you can pass the function as a reference without having to bind it first.

app.use((ctx) => somePromiseCall().then(ctx.ok))

Available methods

ok - HTTP 200
created - HTTP 201
noContent - HTTP 204 - always sends an empty response!
badRequest - HTTP 400
unauthorized - HTTP 401
forbidden - HTTP 403
notFound - HTTP 404
internalServerError - HTTP 500

Does this work for Koa 1?

Not out of the box, because it's time you move on to v2.

To use koa-respond in Koa v1, you need to patch the context yourself. This is what the v2 middleware does.

const respond = require('koa-respond');

// Middleware to install koa-respond.
app.use(function *(next) {
  respond().patch(this);
  yield next;
});

// Now the methods are available.
app.use(function *() {
  this.ok({ id: 123, name: 'Bob' });
});

Adding additional methods

If you feel like some methods are missing, you can add them yourself, like so:

app.use(respond({
  statusMethods: {
    imATeapot: 418,
    enhanceYourCalm: 420
  }
}));

app.use((ctx) => {
  ctx.imATeapot('Hello, a Teapot I am.');
  ctx.enhanceYourCalm({ todo: 'blaze it' });
});

Even more custom methods

If you just want to add shortcuts without adding an additional middleware, you can do that, too.

app.use(respond({
  methods: {
    shizzle: (ctx, message) => {
      ctx.send(200, message + ', fo-shizzle');
    }
  }
}));

app.use((ctx) => {
  // HTTP 200 { message: 'Koa is the best, fo-shizzle' }
  ctx.shizzle('Koa is the best');
});