Rovo Dev CLI and Mutation Testing to Write Better Tests

This post details the application of mutation testing using Pitest in Jira's backend codebases to improve test suite effectiveness. It explains the concept of mutation testing, contrasting it with traditional line coverage, and demonstrates how Pitest identifies 'surviving' mutants. The post then introduces the Rovo Dev CLI as a tool to automate the writing of new tests specifically to catch these mutants. It outlines a process involving running Pitest, analyzing mutation coverage data with MCP tools, identifying code with low coverage, and using Rovo Dev CLI to generate and test new tests until an 80% mutation coverage threshold is met. A sample GitHub repository is provided for users to replicate the process. The post also mentions plans to extend mutation testing to frontend codebases.