Book Image

Mastering Clojure

By : Akhil Wali
Book Image

Mastering Clojure

By: Akhil Wali

Overview of this book

Clojure is a general-purpose language from the Lisp family with an emphasis on functional programming. It has some interesting concepts and features such as immutability, gradual typing, thread-safe concurrency primitives, and macro-based metaprogramming, which makes it a great choice to create modern, performant, and scalable applications. Mastering Clojure gives you an insight into the nitty-gritty details and more advanced features of the Clojure programming language to create more scalable, maintainable, and elegant applications. You’ll start off by learning the details of sequences, concurrency primitives, and macros. Packed with a lot of examples, you’ll get a walkthrough on orchestrating concurrency and parallelism, which will help you understand Clojure reducers, and we’ll walk through composing transducers so you know about functional composition and process transformation inside out. We also explain how reducers and transducers can be used to handle data in a more performant manner. Later on, we describe how Clojure also supports other programming paradigms such as pure functional programming and logic programming. Furthermore, you’ll level up your skills by taking advantage of Clojure's powerful macro system. Parallel, asynchronous, and reactive programming techniques are also described in detail. Lastly, we’ll show you how to test and troubleshoot your code to speed up your development cycles and allow you to deploy the code faster.
Table of Contents (19 chapters)
Mastering Clojure
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
References
Index

Testing with specs


We will now take a look at the Speclj, pronounced speckle, library (https://github.com/slagyr/speclj), which is used to write specs. Specs are similar to unit tests, but are focused on the behavior of functions being tested, rather than their internal implementation. In fact, behavior-driven development (BDD) is centered about writing specs.

The main difference between TDD and BDD is that BDD focuses on the behavior or specifications of functions, rather than their implementation. From this perspective, if we change the internal implementation of a function that has been previously tested, there is a smaller chance that we have to modify the tests, or rather specs, associated with the function. BDD can also be thought of as a refined approach to TDD, in which the interface and behavior of a function is more important than its internal implementation. Now, let's study the various constructs of the Speclj library.

Note

The following library dependencies are required for the...