Design, Testing and IDE's

Design, Testing and IDE's

1. Defensive Design

   • Defensive Design helps to ensure Programs function properly. When Programs are functioning properly they should never break and never produce errors.
     • Programmers try to defend their Programs through Defensive Design, they will try to anticipate how users might misuse their Program, then attempt to prevent it from happening. They will ensure that their Code is Well-Maintained, and they will reduce the number of errors in the Code through Testing.
       • Sanitisation and Validation is are often done using Whitelists and Blacklists. Whitelists tent to be more secure, however they can take a long time to set up and can be too restrictive.
         • Whitelists - A list of all Data that a program should accept - any Data that isn't on the Whitelist will be rejected.
         • Blacklists - A list of all Data that a program should reject - any Data that isn't on the Blacklist will be accepted
         • Sanitisation - Removing any unwanted Characters before passing it through the Program.
         • Validation - Checking if Data meets certain criteria before passing it through the Program.
   • Authentication can help protect your Programs. Authentication can confirm the identity of a user before they're allowed to access certain pieces of Data or features of the program. The most common way of doing this is using Passwords.
     • Common ways to increase security of a Password-Based Authentication system is by forcing users to use strong Passwords, getting them to change their Passwords regularly, limiting the number of failed Authentication attempts before access to an account is lost and by asking for a random selection of Characters from the Password on each Authentication.
       • Programmers should make sure that there program is Well-Maintained. A Well-Maintained program makes it easy for other programmers to understand what the code does. They should also be able to change parts of the source code without the risk of causing problems elsewhere in the code.
         • Comments - They are useful for explaining what the key features of a Program do - well written and clear Comments are fundamental for helping other Programmers understand your Programs.
         • Indentation - They can be used to separate different statements in a Program. This allows other Programmers to see the flow of the Program more clearly and pick out the different features.
         • Variables and Sub-Programs - They should be named so that they refer to what they actually are. This helps Programmers to keep track and recognise what the Variables are all the way through the Program.
       • If a good amount of useful comments are put into the Source Code then it's very easy to produce a summary of what the Program Code actually does using Auto-Documentation.

2. Testing