Program Testing

Testing is intended to show that a program does what it is intended to do and to discover program defects before it is put into use.

Program Testing Goals

• Validation Testing
  • Are we building the right product?
  • To demonstrate to the developer and the customer that the software meets its requirements.
• Defect Testing (Verification)
  • Are we building the product right?
  • To discover situations in which the behavior of the software is incorrect, undesirable, or does not conform to its specification.

An Input-Output Model of Program Testing

V & V confidence

V & V aims to establish confidence that the system is ‘fit for purpose’.

It depends on:

• Software Purpose.
• User Expectations.
• Marketing Environment.

Inspections and Testing

• Software Inspection (Static Verification) is ****Concerned with the analysis of the static system representation to discover problems

  Capability of Inspection

  • No worry about interaction between errors.
  • An incomplete version of a system can be inspected without additional costs.
  • Consider broader-quality Attributes of the program, such as compliance with standards, portability, and maintainability.

  Limit of Inspection

  • Inspection can check conformance with a specification but not conformance with the customer’s real requirements.
  • Inspection cannot check non-functional characteristics such as performance, usability, etc.

• Software Testing (Dynamic Verification) is concerned with exercising and observing product behavior.

  Stages of Testing

  • Development Testing
    • Unit Testing
    • Component Testing
    • System Testing
  • Release Testing
  • User Testing

  Automated Testing → JUnit

  Components of Automated Test:

  • A setup part, where you initialize the system with the test case, namely the inputs and expected outputs.
  • A call part is where you call the object or method to be tested.
  • An assertion part, where you compare the result of the call with the expected result. If the assertion evaluates to true, the test has been successful if false, then it has failed.

  Testing Strategies

  • Partition testing.
  • Guideline-based testing.

  General Testing Guidelines

  • Choose inputs that force the system to generate all error messages.
  • Design Inputs that cause input buffers to overflow
  • Repeat the same input or series of inputs numerous times.
  • Force invalid outputs to be generated.
  • Force computation results to be too large or too small.

Inspections and Testing

A model of the software Testing Process