The task of this thesis is to delve into the problem of testing client components with frequent testing and continuous integration and delivery. In addition to numerous problems that companies face in the development of a software product, the need for testing at every "step" is felt more more important, in which integration proves to be a key step in the delivery of quality software. The goal of this thesis is to highlight the importance of integration and delivery and testing, with going into explanation of some benefits and challenges in case the company decides to use modern technologies. In addition, thesis is also concerned with types of testing with an emphasis on testing client components and the differences between different kind of tests, such as unit testing, integration testing, end-to-end testing etc. After getting insights and theoretical background, it is also important to implement the acquired knowledge in practice and prove these benefits using modern technologies such as Azure DevOps and integration of end-to-end tests. The idea is to prove and deliver a display of the number of tests and their success statuses. Furthermore, the goal of this work is to show the delivery of client components through the creation of a release pipeline, and to conclude the testing with visual regression tests.