Book Image

Django 1.1 Testing and Debugging

Book Image

Django 1.1 Testing and Debugging

Overview of this book

Bugs are a time consuming burden during software development. Django's built-in test framework and debugging support help lessen this burden. This book will teach you quick and efficient techniques for using Django and Python tools to eradicate bugs and ensure your Django application works correctly. This book will walk you step by step through development of a complete sample Django application. You will learn how best to test and debug models, views, URL configuration, templates, and template tags. This book will help you integrate with and make use of the rich external environment of test and debugging tools for Python and Django applications. The book starts with a basic overview of testing. It will highlight areas to look out for while testing. You will learn about different kinds of tests available, and the pros and cons of each, and also details of test extensions provided by Django that simplify the task of testing Django applications. You will see an illustration of how external tools that provide even more sophisticated testing features can be integrated into Django's framework. On the debugging front, the book illustrates how to interpret the extensive debugging information provided by Django's debug error pages, and how to utilize logging and other external tools to learn what code is doing.
Table of Contents (17 chapters)
Django 1.1 Testing and Debugging
Credits
About the Author
About the Reviewer
Preface
Index

Chapter 8. When Problems Hide: Getting More Information

Sometimes code does not trigger a debug page to be displayed, but it also does not produce the correct results. In fact even when code does seem to be working correctly, at least in terms of the visible results shown in the browser, behind the scenes it may be doing unexpected things that could lead to trouble down the road. For example, if a page requires many (or very time-consuming) SQL queries, then it may seem to be working fine during development but then quickly cause server overload in a production environment.

It's good practice, then, to get into the habit of checking up on how code is behaving, even when external results are not showing any problems. First, this practice can reveal hidden problems that are best known about sooner rather than later. Second, knowing what the normal code path looks like is very valuable when tracking down where things have gone wrong when a problem does crop up.

This chapter focuses on ways to...