Page 140 - SOFTWARE TESTING & QUALITY ASSURANCE

Unit 9: Automation Testing

Figure 9.2 depicts a computer that acts as a driver test tool.
Figure 9.2: A Computer that Acts as a Driver Test Tool to
Replace the Keyboard and Mouse of a System Being
Tested.

Here, a computer is being depicted as a driver test tool that can replace the keyboard and mouse of a
system being tested. Assume that the software being tested requires large amounts of data to be entered
in the test cases. If there are a few hardware modifications and a small number of software tools, the
user can replace the keyboard and mouse of the system being tested with an additional computer that
can operate as a driver. With this driver computer, one can write simple programs that automatically
generate the appropriate keystrokes and mouse movements to test the software.
Alternatively, a user can also opt for another method, that is, a user can simply run a program on the
first system that sends keystrokes to the software being tested. But again there are two problems
involved in this. They are:
1. If the software or the operating system is not multitasking, it is not possible to run another driver
program at the same time.
2. If the keystrokes and mouse movements are sent from an external computer, the test system is
non-invasive. If a driver program is being operated on the same system as the software being
tested, it is invasive and may not be considered as an acceptable test scenario.
Stubs
Stubs are used to receive or resend data that the software sends. They do not control or operate the
software being tested. For example,

If a user wants to test software that sends data to a printer, one way to test it is
to enter data, print it, and check the result. This is a slow , incompetent, and
error prone process. It is also difficult to obtain the appropriate results as the
user may not know if the output had a single missing pixel or if the color was
different. Here, accurate results can be obtained if the user replaces the printer
with another computer operating on stub software.

Stubs are often used when the software needs to communicate with external devices. They make the
testing process efficient as they permit testing despite lacking the hardware.

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