If you eg interact with remote apis a lot, you can write the natural code: some api calls for setup, then your business logic, then more api calls... and then test this. In one linear function that is straightforward to understand. With great mock support, no need for code generation for mocking, etc.
Ruby is one of the few languages sharing this excellent support. All the other common languages require some combination of dependency injection, code generation for mocking, spewing unnecessary interfaces all over your code and turning it into a tangled mess of logic smeared across many functions, etc.
If you eg interact with remote apis a lot, you can write the natural code: some api calls for setup, then your business logic, then more api calls... and then test this. In one linear function that is straightforward to understand. With great mock support, no need for code generation for mocking, etc.
Ruby is one of the few languages sharing this excellent support. All the other common languages require some combination of dependency injection, code generation for mocking, spewing unnecessary interfaces all over your code and turning it into a tangled mess of logic smeared across many functions, etc.