NEXT CHAPTER 27 Testing Approach

Unit Testing

Unit testing focuses verification error on the smallest unit of software design – the software component or module. Using the component-level design description as a guide, important control paths are tested to uncover errors within the boundary of the module. The relative complexity of tests and the errors those tests uncover is limited by the constrained scope established for unit testing. The unit test focuses on the internal processing logic can be conducted in parallels for multiple components

Unit Test Considerations:

The tests that occur as part of unit tests are illustrated. The module interface is tested to ensure that information properly flows into and out of the program unit under test. Local data structures are examined to ensure that data stored temporarily maintains its integrity during all control structure are exercised to ensure that all statements in a module have been executed at least once. Boundary conditions are tested to ensure that the module operates properly at boundaries established to limit or restrict processing. And finally all error handling paths are tested.

Test of data flow across a module interface are required before any other test is initiated. If data do not enter and exit properly, all other tests are moot. In addition, local data structures should be exercised and the local impact on global data should be ascertained during unit testing.

Selective testing of execution paths is an essential task during the unit test.

Among the more common errors in Computations are:

1. Blank test box entries.

2. Misunderstood or incorrect Entries i.e. In Name Fields numeric values are entered.

3. Incorrect Initialization.

4. Incorrect symbolic representation of an expression.