The concept of Drivers and Stubs is very important to understand the Integration or Incremental testing. Top down and Bottom up are approaches used in integration testing. Drivers are used for the bottom-up approach where as Stubs are used in top-down approach. Drivers are modules that run the components that are being tested. Stub is a replacement of sorts for a component, which is used to develop and test a component that it calls.
STUBS:
In Top-down approach when lower level components are developed, they are integrated with highest level components. There is a possibility that a lower level module is missing or not yet developed which affect the integration between the other modules.
In this situation to make the integration possible developer develop the temporary dummy program that is utilized in place of missing module known as ‘STUB’ for the smooth running.
In top-down approach, the decision making occurs at the upper level in the hierarchy and encountered first. The problem occurs in this hierarchy when processing the low level or lower level components to adequately test top or highest levels. As stubs are used to replace lower level components at the beginning of top-down approach; no significant data can flow between the modules.
 |
| STUBS |
DRIVER:
Bottom-up approach is the opposite of top-down where lower level components are tested first and proceed upwards to the higher level components. In this approach when highest level components are developed they are integrated with the lower level components. There is possibility of missing highest level components which affect the integration process.
In this situation to make the integration possible developer develop the temporary dummy program that is utilized in place of missing module known as ‘DRIVER’.
 |
| DRIVER |
No comments:
Post a Comment