DELETE vs. idempotence

Methods can also have the property of "idempotence" in that (aside from error or expiration issues) the side-effects of N > 0 identical requests is the same as for a single request. The methods GET, HEAD, PUT and DELETE share this property. Also, the methods OPTIONS and TRACE SHOULD NOT have…

Failures in the presence of side-effects

Failures are difficult, yet our applications tend to fail more than we would want them to. More so, failures in the presence of side-effects are specially dangerous, because we need to somehow revert the changes we’ve applied, but before we do that we need to know how much of…

Promises are functional

callback-based functions do not return anything, and so are hard to compose. A function with no return value is executed only for its side effects – a function with no return value or side effects is simply a black hole. So programming with callbacks is inherently imperative, it is about sequencing…