View Full Version : How to write test cases for dll files

08-22-2007, 05:14 AM
How to write test cases for dll files

Functions in DLLs can be used by more than one running process. The operating system maps the DLLs into the process's address space when the process is started up or while it is running.

Some DLLs are used only by the application that installs them, while otherDLLs come bundled with the Windows operating system and are shared by various applications. Problems arise when required DLLs are missing or whenDLLs are updated by one application and no longer function with the other applications that are sharing them.

To test a DLL one should have a understanding of the function of the specific DLL under test and the expected input parameters required for theDLL. It should be possible to get this info from the Technicalspecification prepared for mandating the DLL code development . In the absence of this document you could use read a user manual if available
forthe DLL (eg "Atlas speaks" which is a Map data program delivering information thru a speech synthesizer needs the Region / country for whichyou need information.....) or have a discussion with the developer on whatthe function of the DLL is & how the DLL is expected to work .
Based on the functionality of the DLL a suite of test cases/scriptsthatexercise all of the functions should be developed. These cases should beprepared for both positive & negative results . Positive to ensure the DLLworks and negative to ensure that the DLL will fail if
the required Parameters are not provided. Testing of dll is similar to functional test any other application .