React: Building Modern Web Applications

Creating multiple specs and expectations

This time, we'll create and test the collection utility module. Create the CollectionUtils.js file in the ~/snapterest/source/utils/ directory:

function getNumberOfTweetsInCollection(collection) {
  var TweetUtils = require('./TweetUtils');
  var listOfCollectionTweetIds = TweetUtils.getListOfTweetIds(collection);

  return listOfCollectionTweetIds.length;
}

function isEmptyCollection(collection) {
  return (getNumberOfTweetsInCollection(collection) === 0);
}

module.exports = {
  getNumberOfTweetsInCollection: getNumberOfTweetsInCollection,
  isEmptyCollection: isEmptyCollection
};

The CollectionUtils module has two methods: getNumberOfTweetsInCollection() and isEmptyCollection().

First, let's discuss getNumberOfTweetsInCollection() ...