The adoption of SOA for
agility, reducing lifetime cost of an application or accelerating time to
market for new business features, does require a change in your current testing
strategy. These changes will reduce the amount of time it takes to test, enabling
you to move faster through test cycles, and will require new activities (e.g.,
automated continuous regression testing). Complete testing of all possible
paths of a program, an application, or system has become impractical if not
cost-prohibitive for organizations (and has been for some time). There are just
too many paths through a program to test; Yet, defects exist, and organizations
must do intelligent testing and full life cycle testing such that defects are
identified. For many test teams or test groups, deploying business applications
into production with defects is way of life, where defects are now categorized
and workaround techniques are communicated in lieu of fixing the defects. It
does not have to be this way.
SOA
provides an opportunity to improve testing when using services. The use of
services promotes black-box testing, where functional tests can focus on valid
inputs and outputs. The service contract defines valid inputs and expected
outputs of a service, which promotes the use of black-box testing and tools to
test the service. Blackbox testing eliminates the need to perform complete
testing of all possible paths of a program, application, or system. In most
environments, testing of a changed or newly deployed application requires
retesting of components in the new system and their connections to downstream
systems. This testing cycle is fraught with errors. Often, it must be performed
in a linear fashion, and calendar time is slowly eaten away, causing a decision
to either delay deployment, turn off features, or simply to live with defects
in a production system (where operator workarounds replace functioning
software). SOA fixes this issue because a deployed and working service does not
need to be retested or included in future test cycles when reusing the service
and deploying a new applications that uses the production-deployed service.
Figure shows the difference of
scope with business applications before and after adopting SOA. In Figure, the
scope of what needs to be tested is larger before SOA. The scope of the test
cycle is less with the use of services when a service life cycle is introduced,
where each service goes through a testing cycle in the same manner as we treat
applications. Just like applications, services do not have to be retested after
they are deployed into production. Services can be certified as satisfying
their contract specifications. This certification provides consumer’s
confidence that the service works as designed and results in less overall
testing when applications are structured using services.
With
SOA adoption, where services are the structuring element of the application,
black-box testing becomes the norm. This avoids the retesting of services
already deployed in production to determine whether the new system,
application, or service has a bug, because services working in production
continue to accept the proper inputs and deliver the correct outputs according
to the service contract. SOA testing is facilitated when automated continuous
regression testing is used. Regression testing facilitates the rapid testing of
services as
