1. A method of unit and regression testing for model aware domain specific languages, the method comprising a processor implemented steps of: modeling an operation present in a repository for a test driven development process, the operation comprising a specification of designing requirements for testing to generate an application library code; generating a blank operation template from the application library code thereof corresponding to the operation, the blank operation template comprising an input XML and an expected output XML thereof, wherein the input XML refers to a set of test cases, and the expected output XML refers to results that are expected post running of the set of the test cases; building an executable unit test load to integrate business logic therein by using predefined unit test stubs and system libraries; executing the unit test load and comparing a resulting actual output XML with the expected output XML to determine states of the set of the test cases, wherein a state of a test case refers to either pass state or fail state; identifying defects unveiled during the comparison; and versioning the test cases for the future reusability by selecting valid test cases with the pass states, wherein the valid test cases are used to build regression test suites, wherein the regression test are used for performing regression testing, wherein regression testing comprises executing an entirety of the regression test suites to uncover unknown defects to all parts of an enterprise computer application due to a change at a unit level of the enterprise computer application.