This is an app that you can use to test React Native Harness in practice. At its core, this is a basic React Native application, bootstrapped via React Native Community CLI.
First, you need to prepare a debug build and install it on a selected device. You can do this as you do for your normal React Native Community CLI app. See React Native docs for details on how to build the app.
To run React Native Harness, you need to execute the pnpm test:harness command. It will collect all tests defined in ./src/__tests__ and execute them one by one. You are free to modify rn-harness.config.mjs to match your local environment, but remember not to include these changes in your pull requests.
See the React Native Harness documentation for details on how to configure the environment.