in today’s scenario it is also the developer’s responsibility to perform at least some of the coding testing. Though it is not expected that he will have the capacity or that his focus should run through the large test plans or test on large stack of devices. However  without the responsibility to review and test his code, a sense of ownership will not develop. we always believe that results will improve if all parties have access to test cases and can run and access them regularly to verify if the latest  changes brought any regression.