Blackbox Testing

This is testing without having an insight into the details of the underlying code.

Here, we based based on a system’s specification, testing actual functionality. Black box testing helps test case generation and test oracles.

Pros and Cons

Pros

• No need for source code
• Wide applicability (unit and systems-level testing) Cons
• Does not test hidden functions

Error Guessing

In this approach, we guess based on experience. Here:

1. Make list of possible errors or error-prone situations
2. Yields an error model
3. Design test cases to cover error model We develop and maintain our own error models. These errors models are the things I would intuitively think to test for. For example, if I’m testing an array sorting function:

• Empty array
• Already sorted array
• Reverse sorted array

Derivation from Functional Requirements

This is the point of black box testing

• Involves clarification and restatement of requirements such that requirements are testable
• Enumerate single requirements and group related requirements
• For each requirement
  • One test case showing the requirement functioning
  • One test case trying to falsify something
  • Test boundaries

Derivation from Use Cases

For each use case:

1. Develop a scenario graph
2. Determine all possible scenarios
3. Analyze and rank scenarios
4. Generate test cases from scenarios to meet coverage goal
5. Execute test cases

• See Scenarios (scenario graphs)

Other ways to do this:

• Equivalence Testing
• Boundary Value Analysis