SetupFiles
SetupFiles is a configuration option used by Jest, the JavaScript testing framework. It specifies an array of module paths that are loaded before each test file is executed. The intent is to polyfill or configure global state so tests can run in a consistent environment, without relying on per-test boilerplate.
Files listed in setupFiles are loaded before the test framework is installed, and they run in the
Unlike setupFilesAfterEnv, which runs after the test framework has been set up, setupFiles is meant for pre-environment