jest-runner-eslint integrates ESLint directly into your Jest testing workflow. It enables linting JavaScript and TypeScript files as part of your Jest test suite, ensuring code quality and consistency. By running ESLint alongside your unit tests, you can catch potential errors and style issues early. The runner streamlines the development process by providing immediate feedback on code changes, preventing common problems from reaching production. Configuration is straightforward, making it a valuable addition for projects focused on code maintainability.