t-up

Tee up a test server in one file, tear it down in another

This makes it easy to set up a server or child process in a test file called 00-setup.js or something, and then tear it down in zz-teardown.js, so that you can get the benefits of running your tests in separate files, but still bang on the same server across the entire suite.

USAGE

You may have a setup file that starts a server, like so:

// 00-setup.js
var tup = require('t-up')

tup(function (done) {
  var http = require('http')
  http.createServer(function (req, res) {
    if (req.url === '/ping') {
      res.end('pong\n')
    } else {
      res.statusCode = 404
      res.end('not found\n')
    }
  }).listen(1337, function () {
    // standard node-style callback
    // if you call this with an error, it'll blow up
    done()
  })
})

Then, a bunch of tests that do things to that server:

// test-ping.js
var t = require('tap')
var http = require('http')

t.test('ping returns pong', function (t) {
  http.get('http://localhost:1337/ping', function (res) {
    t.equal(res.statusCode, 200)
    var pong = ''
    res.on('data', function (d) { pong += d })
    res.on('end', function () {
      t.equal(pong, 'pong\n')
      t.end()
    })
  })
})

And of course, a negative test:

// test-blerg.js
t.test('anything else 404s', function (t) {
  http.get('http://localhost:1337/blerg', function (res) {
    t.equal(res.statusCode, 404)
    var pong = ''
    res.on('data', function (d) { pong += d })
    res.on('end', function () {
      t.equal(pong, 'not found\n')
      t.end()
    })
  })
})

Last but not least, tear down the server when you're done:

// zz-teardown.js
var tup = require('t-up')
tup.close()

CAVEATS

• The module that calls t-up should probably not do anything else. It's going to be run a second time in a child process, so any other side-effects are bad.
• You should use tap for your tests, since this module will output some TAP notes about how it's going.
• Definitely clean up after yourself! If you don't ever call tup.close(), then you'll have a bunch of node processes lying around.
• The server MUST call the done() function when it's ready to move onto the next test. This writes a special key to standard output, and prevents a race condition where the tests fail because the server isn't up yet. Otherwise, all stdio is completely lost, because the child process is abandoned without access to that stuff.