Express Rescue

This is a dependecy free wrapper (or sugar code layer if you will) for async middlewares which makes sure all async errors are passed to your stack of error handlers, allowing you to have a cleaner and more readable code.

How to use it

It's really simple:

const rescue = require('express-rescue')

/**
 * `rescue` insures thrown errors are passed to `next` callback.
 */
app.get('/:id', rescue(async (req, res, next) => {
    const user = await repository.getById(req.params.id)

    if (!user) {
      throw new UserNotFoundError
    }

    res.status(200)
       .json(user)
}))

/**
 * `rescue.from` allows you to handle a specific error which is helpful for
 * handling domain errors.
 */
app.use(rescue.from(UserNotFoundError, (err, req, res, next) => {
    res.status(404)
       .json({ error: 'these are not the droids you\'re looking for'})
})

/**
 * Your error handlers still works as expected. If an error doesn't match your
 * `rescue.from` criteria, it will find its way to the next error handler.
 */
app.use((err, req, res, next) => {
    res.status(500)
       .json({ error: 'i have a bad feeling about this'})
})

That's all.

Hope you enjoy the async/await heaven!

Chears!

Tests

> express-rescue@1.1.26 test /Users/rwillians/Projects/express-rescue
> mocha specs --require ./specs/spec-helper.js

  const callable = rescue(async ([err,] req, res, next) => { })
    calls the last argument (next) with the thrown error
      ✓ All arguments are been passed to the callback
      ✓ Raises a TypeError if last argument is not a function
      ✓ callable(req, res, next) - works for routes and middlewares
      ✓ callable(err, req, res, next) - works for error handler middlewares
      ✓ callable(foo, bar, baz, foobar, foobaz, errorHandler) - should work for basically anything, since you place an error handler as the last argument


  5 passing (7ms)