Editing a test runner or coverage configuration

Holds a file tool opening a test runner's or coverage tool's own configuration: Jest's jest.config.*, Vitest's vitest.config.* and legacy vitest.workspace.*, pytest.ini, pytest.toml and their dotted forms, tox.ini, Mocha's .mocharc.*, PHPUnit's phpunit.xml, phpunit.xml.dist and phpunit.dist.xml, codecov.yml, nyc's .nycrc* and nyc.config.*, .c8rc, coverage.py's .coveragerc, karma.conf.*, and the Playwright and Cypress configs. One line in any of these can exclude a failing file, lower a coverage threshold or retry a flaky test until it passes. Reading is excluded — the Read and Grep tools never match — so opening one of these configs to read it is not held; every other file tool is, including one this corpus does not know. File tools carry a path and no content, so it still cannot tell a harmless edit from a weakening one. Deliberately NOT matched: general files that can also hold test settings — pyproject.toml, setup.cfg, package.json, vite.config.* — and test files themselves, since editing a test is how a test gets fixed. Misses test settings kept in those general files, and a config at a path passed with --config.