Common Design Patterns for Symbian OS: The Foundations of Smartphone Software

2.1. Fail Fast

Intent

Improve the maintainability and reliability of your software by calling Panic() to deal with programming errors as soon as they are detected.

AKA

Programming by Contract [Meyer, 1992]

2.1.1. Problem

2.1.1.1. Context

Detecting faults in your software should be done as early as possible during the development process since it can be over 10 times cheaper to detect them in the early stages of development compared to finding them once your product has shipped [Fagan, 1976].

2.1.1.2. Summary

• You want to reduce the number of defects in your software and so improve the experience for the end user by, for example, avoiding loss of their privacy, corruption of their data, and security vulnerabilities.

• You want to reduce the effort associated with debugging and fixing defects.

• You want to improve the maintainability of your software by making it easier to add new features safely.

2.1.1.3. Description

The problem we're focusing on here is how to detect faults in our software since a common issue when developing software of any complexity is programmer error. These mistakes manifest themselves as defects, some of which will be very apparent while developing a component; others are much more subtle and therefore long-lived and insidious. Although they are all faults, there is a key difference between defects found during the production of a system by its developers and those discovered by end users of the software.

Finding defects during the development of a system ...