Producing Robust Programs

Producing Robust Programs

1. to create programs that are hard to break

2. To create programs that are hard to break

3. Defensive design

   • Protection against unexpected user inputs.
     • Validation
       • Defensive Strategy
       • Ensuring all data entered is sensible and reasonable.
         • Type Check, Length Check, Format check, Range Check, Presence Check
   • Maintainability
     • Reducing the chance of introducing coding mistakes/bugs.
     • To make source code more maintainable, programmers should include
       • Comments, Indentation, Subroutines and Naming Constants
   • Minimising/Removing bugs.
     • Testing
       • Program functions as it was designed and meets the needs of the end user.
       • Iterative testing and Final Testing
       • Test Plans
         • Made of the test data, the reason for the test, the expected outcome and the actual result.
         • Uses different types of data to test how functional it is including. Valid data, invalid data and borderline
   • Authentication
     • Defensive strategy
     • Usernames and Passwords (access rights)