A test comparator is a tool to automate the process of comparison between the actual and expected results produced by a software product at the time of software testing. This automation of comparison can take place during the testing procedure or after the testing procedure is complete.
Test automation tools do cater to tasks such as test data creation, GUI interaction, problem detection, defect logging, product installation etc. Apart from all such requirements, testers must consider the following aspects while testing :
Test comparators are primarily of two types:
Dynamic test comparators:Here the comparison of test results is done in a dynamic scenario i.e. the comparison is done while the tests are being executed. Dynamic test comparators are useful in those scenarios where the actual inference does not match the actual or expected inference at a time when the product is in the midst of a test cycle and an urgent recovery action is the need of the hour.
Static test comparators:Here the comparison of test results is done in a static environment i.e. when the software product under test is no longer running. The comparison of test results takes place after all the test cases have been executed. Static test comparators are generally useful for comparison of enormous amount of data. For instance, verifying the records of a database with the similar or expected data of those records.