old_contents: 'use strict';
  
  var assert = require('assert');
  var fs = require('fs');
  var path = require('path');
  
  var transform = require('../');
  
  var input = fs.readFileSync(__dirname + '/input.scss', 'utf8');
  var expected = fs.readFileSync(__dirname + '/expected.css', 'utf8');
  var expectedImport = fs.readFileSync(__dirname + '/expected-import.css', 'utf8');
  
  var res = transform.render(input);
  fs.writeFileSync(__dirname + '/output.css', res.body);
  assert(res.body === expected, 'output.css should equal expected.css');
  assert.deepEqual(res.dependencies, [], 'expected dependencies to be an empty array');
  
  var res = transform.renderFile(__dirname + '/input.scss');
  fs.writeFileSync(__dirname + '/output.css', res.body);
  assert(res.body === expected, 'output.css should equal expected.css');
  assert.deepEqual(res.dependencies, [], 'expected dependencies to be an empty array');
  
  var res = transform.renderFile(__dirname + '/import.scss');
  fs.writeFileSync(__dirname + '/output.css', res.body);
  assert(res.body === expectedImport, 'output.css should equal expected-import.css');
  assert.deepEqual(res.dependencies, [path.resolve(__dirname + '/input.scss')]);
  
  
  transform.renderAsync(input).then(function (res) {
    fs.writeFileSync(__dirname + '/output.css', res.body);
    assert(res.body === expected, 'output.css should equal expected.css');
    assert.deepEqual(res.dependencies, [], 'expected dependencies to be an empty array');
    return transform.renderFileAsync(__dirname + '/input.scss');
  }).then(function (res) {
    fs.writeFileSync(__dirname + '/output.css', res.body);
    assert(res.body === expected, 'output.css should equal expected.css');
    assert.deepEqual(res.dependencies, [], 'expected dependencies to be an empty array');
    return transform.renderFile(__dirname + '/import.scss');
  }).then(function (res) {
    fs.writeFileSync(__dirname + '/output.css', res.body);
    assert(res.body === expectedImport, 'output.css should equal expected-import.css');
    assert.deepEqual(res.dependencies, [path.resolve(__dirname + '/input.scss')]);
  }).done(function () {
    console.log('test passed');
  });
  
new_contents: 'use strict';
  
  var assert = require('assert');
  var fs = require('fs');
  var path = require('path');
  
  var transform = require('../');
  
  var input = fs.readFileSync(__dirname + '/input.scss', 'utf8');
  var expected = fs.readFileSync(__dirname + '/expected.css', 'utf8');
  var expectedImport = fs.readFileSync(__dirname + '/expected-import.css', 'utf8');
  
  var res = transform.render(input);
  fs.writeFileSync(__dirname + '/output.css', res.body);
  assert(res.body === expected, 'output.css should equal expected.css');
  assert.deepEqual(res.dependencies, [], 'expected dependencies to be an empty array');
  
  var res = transform.renderFile(__dirname + '/input.scss');
  fs.writeFileSync(__dirname + '/output.css', res.body);
  assert(res.body === expected, 'output.css should equal expected.css');
  assert.deepEqual(res.dependencies, [], 'expected dependencies to be an empty array');
  
  var res = transform.renderFile(__dirname + '/import.scss');
  fs.writeFileSync(__dirname + '/output.css', res.body);
  assert(res.body === expectedImport, 'output.css should equal expected-import.css');
  assert.deepEqual(res.dependencies, [path.resolve(__dirname + '/input.scss')]);
  
  
  transform.renderAsync(input).then(function (res) {
    fs.writeFileSync(__dirname + '/output.css', res.body);
    assert(res.body === expected, 'output.css should equal expected.css');
    assert.deepEqual(res.dependencies, [], 'expected dependencies to be an empty array');
    return transform.renderFileAsync(__dirname + '/input.scss');
  }).then(function (res) {
    fs.writeFileSync(__dirname + '/output.css', res.body);
    assert(res.body === expected, 'output.css should equal expected.css');
    assert.deepEqual(res.dependencies, [], 'expected dependencies to be an empty array');
    return transform.renderFileAsync(__dirname + '/import.scss');
  }).then(function (res) {
    fs.writeFileSync(__dirname + '/output.css', res.body);
    assert(res.body === expectedImport, 'output.css should equal expected-import.css');
    assert.deepEqual(res.dependencies, [path.resolve(__dirname + '/input.scss')]);
  }).done(function () {
    console.log('test passed');
  });
  
subject: Fix async test