Our company is in the medical X-Ray industry and we are creating a dll to be used with our software for the first time!!! I / we are new to testing of dll's and I was wondering if anyone know of any web sites, forums or books relating to testing of dll's.
This will be a windows based dll from what I understand. Sorry but I do not have the Spec yet as to what it does! Just doing some prelim research.
Usually a dll will plug into your software and provide some added capability that can be tested through your normal testing methods. On rare occassions, dlls will be created that are stand-alone and you'd have to code some kind of test harness to access its functions. Try a search here for 'dll' and see if that pulls up any posts from the past.
If, as Bryan points out, you are going to write code to test the functions directly, try searching the forums for "API" or perhaps "toolkit." These might provide additional info.
DLLs are libraries that provide functions that enable another program to do something with your application. This is also called and API if it is a published interface that your customers will use.
The way to test libraries is by writing code (or getting somebody to write it for you) that exercises these functions. From a testing point of view the questions are the same than if the functions were called by the application. One way you can think of a function is as a "screen" in your application with the input and output parameters being the controls on your screen. All the tests that you would apply to these controls are probably valid tests.
Some of the things to check for are:
- Valid & Invalid values for parameters
- Calling functions in the right order
- Other pre-requisites for the functions (eg call function without any connected equipment)
Another term that might help you is Unit Testing as that is usually concerned with testing this kind of interface.
Apologies if you already knew all of this, but it might help you get an idea about how to get started with your dll.