| Ticket is a class do ... end is how you create no-argument functions similar to () => { ... } in JavaScript. There's some technical nuance but that's the spirit of it. In Ruby you can call methods without needing to place parentheses. So this roughly translates to the JavaScript code: RSpec.describe(Ticket, () => { context('when...', () => {
...
});
});This specific code describes a test that uses the RSpec testing framework. In RSpec, "context" and "it" are just functions that you call to describe chunks of tests and individual tests respectively. Some Rubyists would say that the combination of these syntax rules (do-end and optional parentheses for function calls) allow you to make "domain specific languages" (DSLs as they're known in the community) without needing to write your own parser. I think it's pretty plain to see the impact in expressiveness if you look at the equivalent Python unittest suite. The Python equivalent would have classes that inherit unittest.TestCase and methods named like test_when_ticket_is_closed. In Python land, classes and method declarations are repurposed because the syntax is what it is. In Ruby, you can practically make your own faux keywords by abusing do-end to accept nested blocks. |