old_contents: 'use strict';
  
  require('should');
  
  var hydrater = require('../lib/');
  
  describe('Test changes', function() {
    it('returns the correct informations', function(done) {
      var document = {
        metadata: {
          startDate: new Date()
        }
      };
  
      var changes = {};
  
      hydrater(null, document, changes, function(err, changes) {
        changes.should.have.property('modification_date', document.metadata.startDate);
        done();
      });
    });
  
    it('returns an empty changes without start date', function(done) {
      var document = {
        metadata: {}
      };
  
      var changes = {};
  
      hydrater(null, document, changes, function(err, changes) {
        changes.should.not.have.property('metadata');
        done();
      });
    });
  });
  
new_contents: 'use strict';
  
  require('should');
  
  var hydrater = require('../lib/');
  
  describe('Test changes', function() {
    it('returns the correct information', function(done) {
      var document = {
        metadata: {
          startDate: new Date()
        }
      };
  
      var changes = {};
  
      hydrater(null, document, changes, function(err, changes) {
        changes.should.have.property('modification_date', document.metadata.startDate);
        done();
      });
    });
  
    it('returns an empty changes without start date', function(done) {
      var document = {
        metadata: {}
      };
  
      var changes = {};
  
      hydrater(null, document, changes, function(err, changes) {
        changes.should.not.have.property('metadata');
        done();
      });
    });
  });
  
subject: Fix typo