Comparison

At this point of the chapter, we should have a better understanding of what options we have to tame the asynchronous nature of Node.js. Each one of the solutions presented has its own pros and cons. Let's summarize them in the following table:

Solutions	Pros	Cons
Plain JavaScript	Does not require any additional library or technology Offers the best performances Provides the best level of compatibility with third-party libraries Allows the creation of ad hoc and more advanced algorithms	Might require extra code and relatively complex algorithms
Async	Simplifies the most common control flow patterns Is still a callback-based solution Good performances	Introduces an external dependency Might still not be enough for advanced flows
Promises	Greatly simplify the most common control flow patterns Robust error handling Part of the ES6 specification Guarantee deferred invocation of onFulfilled and onRejected	Might require an external dependency Require to promisify callback-based...