Abstract—JavaScript is expected to be a programming language of even wider use, considering demands for more interactive web/mobile applications and deployment in server-side software. While reliability of JavaScript code will be of more importance, testing techniques for the language remain insufficient, compared to other languages. We propose a technique to automatically generate high-coverage unit tests for JavaScript code. The tech-nique makes use of symbolic execution engine for JavaScript, and symbolic stub/driver generation engine, which injects symbolic variables to system under test. Our methodology allows for automatic generation of input data for unit testing of JavaScript code with high coverage, which ensures quality of target code with reduced effort. Keywords–JavaScript; test generation; symbolic execution; sym-bolic stub and driver generation. I.