Home/ Questions/Q 1019497
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-16T11:01:20+00:00

I am new to unit testing. Suppose I am building a web application. How

  • 0

I am new to unit testing. Suppose I am building a web application. How do I know what to test? All the examples that you see are some sort of basic sum function that really has no real value, or at least I’ve never written a function to add to inputs and then return!

So, my question…on a web application, what are the sort of things that need tested?

I know that this is a broad question but anything will be helpful. I would be interested in links or anything that gives real life examples as opposed to concept examples that don’t have any real life usage.

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    Take a look at your code, especially the bits where you have complex logic with loops, conditionals, etc, and ask yourself: How do I know if this works?

    If you need to change the complex logic to take into account other corner cases then how do you know that the changes you introduce don’t break the existing cases? This is precisely what unit testing is intended to address.

    So, to answer your question about how it applies to web applications: suppose you have some code that lays out the page differently depending on the browser. One of your customers refuses to upgrade from IE6 and insists that you support that. So you unit test your layout code by simulating the connection string from IE6 and checking that the layout is what you expect.

    A customer tells you they’ve found a security hole where using a particular cookie will give you administrator access. How do you know that you’ve fixed the bug and it doesn’t happen again? Create a unit test for it, and run the unit tests on a daily basis so that you get an early warning if it fails.

    You discover a bug where users with accents in their names get corrupted in the database. Abstract out the webform input from the database layer and add unit tests to ensure that (eg) UTF8 encoded data is stored in the database correctly and can be retrieved.

    You get the idea. Anywhere where part of the process has a well-defined input and output is ideal for unit testing. Anything that doesn’t is ideal for refactoring until it is well defined. Take a look at projects such as WebUnit, HTMLUnit, XMLUnit, CSSUnit.

    • 0