I start my work with researching the related literature, during which I present the types of software testing. I emphasize unit testing which I used in the rest of the thesis. The paper touches on the importance of mock files, which can replace the original resource demanding dependencies during tests. I present the types of software analysis, which can be used for exploration of dependencies. I also introduce the tools, which I work with in this thesis. Furthermore, I show how I got familiar with the Jest test- and Jalangi2 analysis frameworks. I design a workflow of a mock generator tool, which is based on the acquired knowledge from the researched literature. The tool can work in two different ways that cover the most likely behaviors, which a mock can have. Also, I propose the structure of the tool I implemented during my work. Furthermore, I introduce the problems arised during the implementation as well as their solutions in detail. In the thesis, I introduce the step-by-step usage of the tool through an example project. Based on the acquired experiences, present recommendations for the further development of the implemented tool.