Developer testing tools are software programs used by developers to automate testing processes and ensure the quality of their code. These tools help developers to quickly identify bugs and issues in their code, allowing them to fix the problems before the software is released to production. Test automation is a key aspect of developer testing tools, as it enables developers to run tests automatically and repeatedly, saving time and effort in the testing process. By utilizing developer testing tools, developers can improve the overall quality of their software and deliver more reliable products to their users.