merry

---

Merry is a little Node framework that helps you build performant applications
with little effort. We don't think that "fast" and "cute" should be mutually
exclusive. Out of the box we've included consistent logging, standardized error
handling, a clean streams API and plenty of nuts, bolts and options to
customize merry to fit your use case. We hope you have a good time using it.
:v: _-Team Merry_

Features

- __fast:__ using Node streams, merry handles request like no other
- __fun:__ helps with boring stuff like error handling
- __communicative:__ standardized [ndjson][ndjson] logs for everything
- __sincere:__ doesn't monkey patch Node's built-ins
- __linear:__ smooth sailing from tinkering to production
- __very cute:__ 🌊🌊⛵️🌊🌊

Table of Content

- Usage
- Logging
- Error Handling
- Configuration
- Routing
- Middleware
- HTTP2
- API
- Installation
- See Also

Usage

``js
var merry = require('merry')

var app = merry()

app.route('GET', '/', function (req, res, ctx) {
ctx.log.info('oh hey, a request here')
ctx.send(200, { cute: 'butts' })
})

app.route('default', function (req, res, ctx) {
ctx.log.info('Route doesnt exist')
ctx.send(404, { message: 'nada butts here' })
})

app.listen(8080)
`

`sh
$ node index.js | merry
`

Logging


Merry uses the pino logger under the hood. When you create a new merry app,
we enable a log forwarder that by default prints all logs to process.stdout.

There are different log levels that can be used. The possible log levels are:
- __debug:__ used for developer annotation only, should not be enable in
production
- __info:__ used for transactional messages
- __warn:__ used for expected errors
- __error:__ used for unexpected errors
- __fatal:__ used for critical errors that should terminate the process

`js
var merry = require('merry')
var app = merry()

app.route('GET', '/', function (req, res, ctx) {
ctx.log.debug('it works!')
ctx.log.info('hey')
ctx.log.warn('oh')
ctx.log.error('oh no!')
ctx.log.fatal('send help')
})
`

The difference between an expected and unexpected error is that the first is
generally caused by a user (e.g. wrong password) and the system knows how to
respond, and the latter is caused by the system (e.g. there's no database) and
the system doesn't know how to handle it.

Error handling

Error handling is different for each application. Errors come in different
shapes, have different status codes, so we can't provide a one-size-fits-all
solution. But we do think that having consistent error messages is useful, so
Merry comes with a recommended pattern to handle errors.

`js
// errors.js
exports.ENOTFOUND = function (req, res, ctx) {
ctx.log.warn('ENOTFOUND')
ctx.send(404, {
type: 'invalid_request_error',
message: 'Invalid request data'
})
}

exports.EDBOFFLINE = function (req, res, ctx) {
ctx.log.error('EDBOFFLINE')
ctx.send(500, {
type: 'api_error',
message: 'Internal server error'
})
}
`

`js
// index.js
var errors = require('./errors')
var merry = require('merry')
var db = require('my-cool-db')

var app = merry()

app.route('GET', '/', function (req, res, ctx) {
db.get('some-key-from-request', function (err, data) {
if (err) return errors.ENOTFOUND(req, res, ctx)
ctx.send(200, data)
})
})

app.listen(8080)
`

Configuration

Generally there are two ways of passing configuration into an application.
Through files and through command line arguments. In practice it turns out
passing environment variables can be done with less friction than using files.
Especially in siloed environments such as Docker and Kubernetes where mounting
volumes can at times be tricky, but passing environment variables is trivial.

Merry ships with an environment argument validator that checks the type of
argument passed in, and optionally falls back to a default if no value is
passed in. To set the (very common) $PORT variable to default to 8080 do:
`js
var merry = require('merry')
var env = { PORT: 8080 }
var app = merry({ env: env })
app.listen(app.env.PORT)
`

And then from the CLI do:
`sh
node ./server.js
// => port: 8080

PORT=1234 node ./server.js
// => port: 1234
`

Routing


Merry uses server-router under the hood to create its routes. Routes are
created using recursive arrays that are turned into an efficient trie
structure under the hood. You don't need to worry about any of this though; all
you need to know is that we've tested it and it's probably among the fastest
methods out there. Routes look like this:
`js
var merry = require('merry')
var app = merry()
app.route('GET', '/', handleIndex)
app.route('PUT', '/foo', handleFoo)
app.route('GET', '/foo/:bar', handleFoobarPartial)
app.listen()
`

Partial routes can be set using the ':' delimiter. Any route that's
registered in this was will be passed to the ctx argument as a key. So
given a route of /foo/:bar and we call it with /foo/hello, it will show up
in ctx as { bar: 'hello' }.

Middleware


We do provide you with a way to access your route's ctx via app.use
`js
var merry = require('merry')
var app = merry()
app.use(function (req, res, ctx) {
ctx.foo = 'bar'
})
`

HTTP2

For http2 support you will need to provide a
key and a cert to establish a secure connection. These can be passed as
part of merry's opts. If http2 is not available, an error will be thrown to
upgrade your node version to > v8.4.0.
`js
var merry = require('merry')
var fs = require('fs')

var opts = {
key: fs.readFileSync('server-key.pem'),
cert: fs.readFileSync('server-cert.pem')
}
var app = merry(opts)

app.listen(8080)
`

API

$3

Create a new instance of merry. Takes optional opts:
- __opts.logLevel:__ defaults to 'info'. Determine the cutoff point for
logging
- __opts.logStream:__ defaults to process.stdout. Set the output writable stream to
write logs to
- __opts.env:__ pass an object containing env var assertions
- __opts.key:__ key to create an http2 connection
- __opts.cert:__ cert to create an http2 connection

$3

Allows you to modify req, res and ctx objects prior to handling a route.

$3

Register a new handler for a route and HTTP method. Method can be either a
single HTTP method, or an array of HTTP methods.

$3

Register a new default handler that will be called if no other handlers match.

#### routes
Each route has a signature of (req, res, ctx):
- __req:__ the server's unmodified req object
- __res:__ the server's unmodified res object
- __ctx:__ an object that can contain values and methods

#### ctx.params
Parameters picked up from the router using the :route syntax in the route.

#### ctx.env
Environment variables passed into the choo({ env }) constructor.

#### ctx.log[loglevel]\([…data])
Log data. Loglevel can be one of trace, debug, info, warn, error,
fatal. Can be passed varying arguments.

#### ctx.send(statusCode, data, [headers])
Efficiently encode JSON, set the appropriate headers and end the request. Uses
streams under the hood.

#### ctx.parse(jsonStream, callback(err, data))
Parse a stream of JSON into an object. Useful to decode a server's req stream
with.

$3


Create a handler that can be passed directly into an http server.

`js
var merry = require('merry')
var http = require('http')

var app = merry()
app.route('GET', '/', handleRoute)

var handler = app.start()
var server = http.createServer(handler)
server.listen(8080)

function handleRoute (req, res, ctx, done) {
done(null, 'hello planet')
}
`

$3


Start the application directly and listen on a port:
`js
var merry = require('merry')

var app = merry()
app.route('GET', '/', handleRoute)
app.listen(8080)

function handleRoute (req, res, ctx, done) {
done(null, 'hello planet')
}
`

Installation


`sh
$ npm install merry
``

See Also

- yoshuawuyts/choo - fun frontend framework
- yoshuawuyts/bankai - streaming asset compiler
- yoshuawuyts/server-router - efficient server router
- lrlna/pino-colada - cute ndjson formatter

License

MIT

[0]: https://img.shields.io/badge/stability-experimental-orange.svg?style=flat-square
[1]: https://nodejs.org/api/documentation.html#documentation_stability_index
[2]: https://img.shields.io/npm/v/merry.svg?style=flat-square
[3]: https://npmjs.org/package/merry
[4]: https://img.shields.io/travis/shipharbor/merry/master.svg?style=flat-square
[5]: https://travis-ci.org/shipharbor/merry
[6]: https://img.shields.io/codecov/c/github/shipharbor/merry/master.svg?style=flat-square
[7]: https://codecov.io/github/shipharbor/merry
[8]: http://img.shields.io/npm/dm/merry.svg?style=flat-square
[9]: https://npmjs.org/package/merry
[10]: https://img.shields.io/badge/code%20style-standard-brightgreen.svg?style=flat-square
[11]: https://github.com/feross/standard
[pino]: https://github.com/pinojs/pino
[ndjson]: http://ndjson.org/
[corsify]: https://github.com/Raynos/corsify