highland-callback/test/test.js

Call a node callback with an optional error after stream completes.

var _ = require('highland'),
    assert = require('chai').assert,
    highlandCallback = require('../index');

describe('highland callback', function() {
  it('calls after the stream is complete', function(done) {
    var order = [];
    _([1, 2, 3])
    .consume(highlandCallback(callback))
    .doto(function(value) {
      order.push(value);
    })
    .resume();

    function callback(error) {
      assert.isUndefined(error);
      assert.deepEqual(order, [1, 2, 3]);
      done();
    }
  });

  it('only calls once', function(done) {
    var timesCalled = 0;

    _(function(push, next) {
      push(null, 1);
      push(null, 2);
      push(null, 3);
      push(null, _.nil);
    })
    .consume(highlandCallback(callback))
    .apply(function() {
      assert.equal(timesCalled, 1);
      done();
    });

    function callback(error) {
      timesCalled++;
    }
  });

  it('propagates the first error', function(done) {
    _(function(push, next) {
      push(new Error('broken'));
      push(null, 1);
      push(new Error('broken2'));
      push(null, 2);
      push(new Error('broken3'));
      push(null, 3);
      push(null, _.nil);
    })
    .consume(highlandCallback(callback))
    .resume();

    function callback(error) {
      assert.isTrue(error instanceof Error);
      assert.equal(error.message, 'broken');
      done();
    }
  });
});