streamer/tests/utils.js

Asynchronously recursive, pure function <3 via lazy streams.

/* vim:set ts=2 sw=2 sts=2 expandtab */
/*jshint asi: true newcap: true undef: true es5: true node: true devel: true
         forin: true */
/*global define: true */

!(typeof define === "undefined" ? function ($) { $(require, exports, module) } : define)(function (require, exports, module, undefined) {

'use strict';

exports.test = function test(assert, done, stream, expected, reason) {
  var actual = []
  stream(function next(element) {
    actual.push(element)
  }, function stop(error) {
    assert.deepEqual(error, reason, 'stream is stopped as expected')
    assert.deepEqual(actual, expected,
                     'all elements were yielded in correct order')
    done()
  })
}

exports.pipe = function pipe(readers) {
  return function stream(next, stop) {
    readers.push({ next: next, stop: stop })
  }
}

exports.read = function read(stream, done, length) {
  var buffer = []
  length = length || Infinity
  stream(function onNext(element) {
    buffer.push(element)
    // Interrupt reading if read desired length
    return buffer.length !== length
  }, function onStop(reason) {
    if (done) done(reason)
  })
  return buffer
}

});