This poster presents SynpleTest, a teaching tool created for introductory computer science courses. SynpleTest uses program synthesis to generate code based on test cases given by the user. Students must continue to add test cases until SynpleTest generates the program they desire. By doing this, our program teaches the student the importance of producing thoughtful and diverse test cases to improve fundamental understanding of testing programs. Preliminary experimentation in classrooms is underway and initial results of usability and effectiveness are being analyzed.