Chapter 3 is where the actual implementation of our email newsletter project (the driving example) begins.
We take off by copy-pasting the "Hello World!" example on actix-web's website and then we pick it apart to understand what each component is doing (HttpServer, App, Route, actix_rt, etc.).
We slowly reshape it into an health check endpoint and then spend the remaining 60% or so of the article looking at how to write a black-box integration test for it.
I haven't published the entire Chapter 3 - it has been split in two parts to keep the publishing cadence (once every two weeks).
The second half will come out on August 23rd and tackle database migrations, how to check side-effects in integration tests as well as actix-web's extractors. At the end of it we should finally be able to onboard new subscribers to the newsletter via a form.