In Configure Jest To Run A Test Setup
File,
I pointed to a way of configuring Jest in either the package.json or
jest.config.js file with the setupTestFrameworkScriptFile value.
In a create-react-app project, this is not an option because
setupTestFrameworkScriptFile is not one of the permitted config values for
Jest.
There is a built-in value which happens to match what was recommended in the
above post -- <rootDir>src/setupTests.js.
This means that there is no configuration required. Instead, just create a
setupTests.js file in the src directory of your CRA project and add any
framework setup you need there. That file is already configured to run when
you invoke yarn test.