Unit testing

Some parts of the examination require implementing methods adhering to a given specification. Consider an example:

Figure 300. Recommended reading Slide presentation

Figure 301. Test categories Slide presentation

  • Unit test: Test individual methods, classes and packages in isolation.

  • Integration Test: Test a group of associated components/classes.

  • Acceptance / Functional Test: Operate on a fully integrated system, testing against the user interface.

  • Regression Test: Ensure system integrity after (implementation) change.

  • Load test: Responsiveness vs. system load.


Figure 302. Example: Computing prime numbers Slide presentation

Informal problem specification:

A prime number is a whole number greater than 1 whose only factors are 1 and itself.

Sample values: 2, 3, 5, 7, 11, 13, 17, 23, ...


Figure 303. Unit test principle Slide presentation
  • Sd1/ObjectsClasses/Fig/unitTest-0
  • Sd1/ObjectsClasses/Fig/unitTest-1
  • Sd1/ObjectsClasses/Fig/unitTest-2
  • Sd1/ObjectsClasses/Fig/unitTest-3
  • Sd1/ObjectsClasses/Fig/unitTest-4
  • Sd1/ObjectsClasses/Fig/unitTest-5
  • Sd1/ObjectsClasses/Fig/unitTest-6
  • Sd1/ObjectsClasses/Fig/unitTest-7
‹›


Figure 304. Test driven development Slide presentation

First write tests, then implement.


Figure 305. Steps in Unit Testing Slide presentation

  1. Specify but not yet implement classes / methods.

  2. Write skeleton (dummy) implementations.

  3. Write corresponding unit tests.

  4. Implement skeleton.

  5. Test your implementation.


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