Software Testing

Unit Tests
The major benefits to be had from unit testing are

1. It allows the developer test parts of an application without waiting for the other parts to be available.

2. Exceptional conditions can be tested for the unit

3. The debugging process is simplified by limiting the search for bugs to a small unit rather than the complete application.

4. It helps avoid lengthy compile-build-debug cycles when debugging difficult problems.

5. Detection and removal of defects can be done at a much lower cost.

Integration Testing
The purpose of this kind of testing is to verify whether the major subsystems of the application are integrated. It helps in uncovering the errors that may arise due to conflicts between different units of an application. Integration testing is performed in different ways.

Bottom Up Approach: The testing is commenced from the smallest subsystem and progresses up the hierarchy to cover the whole system. This methodology requires the developer to write a number of test driver programs that test the integration between the subsystems.

Top down Approach: This begins at the top. The top level interfaces are first tested and then the smaller sub systems are examined. Stubs are written for modules that are not ready for testing.

Umbrella Approach: The focus in this methodology is on testing the modules that have a high degree of user interaction. Stubs are used in place of process intensive modules. This enables the developer test the graphical user interface and improves the functionality of the interface.

Regression Testing
Regression testing is performed whenever the program is modified. The process involves the rerun of all the tests mentioned in the preceding sections. It has two main goals:

1. Verification of known bugs that were corrected
2. Verification of new bugs.

Testing International Applications
Applications created for international usage are to be tested by checking for the language, the country and dependencies. The following factors are to be considered when testing such applications:

• Whether the application’s data and user interface conform to the locale’s standards for date, time, numeric values, currency, list separators and measurements.
• Whether the application runs on different languages and culture variants.
• If Unicode has not been used in the application the culture/locale code of the operating system will have to be set to the localized version of the application.
• The Input data in the language should be supported by the localized version.
• In this section of the lesson we have focused upon the testing of Windows applications. In the sections that follow we shall briefly look at tracing windows applications.