The developer carries out unit testing in order to check if the particular
module or unit of code is working fine.
A D V E R T I S E M E N T
The Unit Testing comes at the very basic
level as it is carried out as and when the unit of the code is developed or a
particular functionality is built. Unit testing deals with testing a unit
as a whole. This would test the interaction of many
functions but confine the test within one unit. The exact scope of a unit is
left to interpretation. Supporting test code, sometimes called scaffolding, may
be necessary to support an individual test. This type of testing is driven by
the architecture and implementation teams. This focus is also called black-box
testing because only the details of the interface are visible to the test.
Limits that are global to a unit are tested here. In the construction industry,
scaffolding is a temporary, easy to assemble and disassemble, frame placed
around a building to facilitate the construction of the building. The
construction workers first build the scaffolding and then the building. Later
the scaffolding is removed, exposing the completed building. Similarly, in
software testing, one particular test may need some supporting software. This
software establishes an environment around the test. Only when this environment
is established can a correct evaluation of the test take place. The scaffolding
software may establish state and values for data structures as well as providing
dummy external functions for the test. Different scaffolding software may be
needed from one test to another test. Scaffolding software rarely is considered
part of the system. Sometimes the scaffolding software becomes larger than the
system software being tested. Usually the scaffolding software is not of the
same quality as the system software and frequently is quite fragile. A small
change in the test may lead to much larger changes in the scaffolding. Internal
and unit testing can be automated with the help of coverage tools. A coverage
tool analyzes the source code and generates a test that will execute every
alternative thread of execution. It is still up to the programmer to combine
this test into meaningful cases to validate the result of each thread of
execution. Typically, the coverage tool is used in a slightly different way.
First the coverage tool is used to augment the source by placing informational
prints after each line of code. Then the testing suite is executed generating an
audit trail. This audit trail is analyzed and reports the percent of the total
system code executed during the test suite. If the coverage is high and the
untested source lines are of low impact to the system's overall quality, then no
more additional tests are required.
STATIC & DYNAMIC ANALYSIS
Static analysis involves going through the code in order to find out any
possible defect in the code. Dynamic analysis involves executing the code and
analyzing the output.
