That's a zero-argument method but not a zero-argument function. That is, if you view makeAvailable as a function, storeItem is an implicit argument to it. In fa

That's a zero-argument method but not a zero-argument function. That is, if you view makeAvailable as a function, storeItem is an implicit argument to it. In fact, storeItem is probably an object with several fields, so there are arguably several implicit arguments. To my eye, the name "makeAvailable" suggests a side-effect too. In any case, it's fine for two rules such as "avoid side effects" and "prefer zero- or single-argument functions" to be in tension with one another. I don't buy that zero-or-one idea, though. A function should have as many arguments as it makes sense for it to have.