June 2009
Intermediate to advanced
494 pages
14h 7m
English
Content preview from Erlang ProgrammingBecome an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
Chapter 19. EUnit and Test-Driven Development
As you are writing a program, how do you understand how the program will behave?
You might have a model in your mind of what the program will do, but you can
be sure of it only when you exercise or
interact with your program in some way. Chapter 18 showed you how you can use –spec to express what you think the input and
output types of a function should be; TypEr can check whether this is
consistent with the code itself.
Types don’t tell you how a program behaves, however, and testing is one of the best ways to understand how your code will function. We have been doing this informally throughout the book; each time we have given some definitions, we have immediately gone to the Erlang shell and tried them out in practice. When you’re developing in Erlang your coding and test cycles tend to be small. You write a few functions, and you test them. You add a few more, and you test them again. Repeating all of the tests in the shell every time becomes both time-consuming and error-prone.
In this chapter, we’ll introduce the EUnit tool, which gives you a framework for unit testing in Erlang. We’ll show how it is used in practice, as well as discuss how it supports what is known in software engineering circles as test-driven development.
Test-Driven Development
The waterfall model of software development saw a software system being developed in a series of steps: first, the requirements of the system would be elucidated; on the basis of this, the ...
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.