Book Image

Software Test Design

By : Simon Amey
Book Image

Software Test Design

By: Simon Amey

Overview of this book

Software Test Design details best practices for testing software applications and writing comprehensive test plans. Written by an expert with over twenty years of experience in the high-tech industry, this guide will provide you with training and practical examples to improve your testing skills. Thorough testing requires a thorough understanding of the functionality under test, informed by exploratory testing and described by a detailed functional specification. This book is divided into three sections, the first of which will describe how best to complete those tasks to start testing from a solid foundation. Armed with the feature specification, functional testing verifies the visible behavior of features by identifying equivalence partitions, boundary values, and other key test conditions. This section explores techniques such as black- and white-box testing, trying error cases, finding security weaknesses, improving the user experience, and how to maintain your product in the long term. The final section describes how best to test the limits of your application. How does it behave under failure conditions and can it recover? What is the maximum load it can sustain? And how does it respond when overloaded? By the end of this book, you will know how to write detailed test plans to improve the quality of your software applications.
Table of Contents (21 chapters)
Part 1 – Preparing to Test
Part 2 – Functional Testing
Part 3 – Non-Functional Testing
Appendix – Example Feature Specification

Using boundary value analysis

Within a partition, not all values are equally important. Bugs are much more likely on the boundaries of partitions where off-by-one errors may be present, for instance, if greater-than-or-equals is used instead of equals. The idea is simple enough: when there is a boundary, you need to test the values just lower and higher to ensure the divide is in the right place.

As with equivalence partitions, boundaries might be explicitly listed within the specifications or they may be implicit aspects of how a feature was implemented. Examples of explicit boundaries are:

  • Tax rates: The values up to X thousand are taxed at one rate, and values from X to Y thousand are taxed at another
  • Ages: Users below 13 are banned, users between 13 and 18 get a child account, and users over 18 get an adult account
  • Passwords: The length of passwords must be over eight characters

Examples of implicit boundaries will depend on your product’s implementation...