Documentation clarification on extend()

[bradvogel]

The documentation seems to imply that extend() will extend the current timeout by X ms. So I'd think this would extend the lock to 15sec:

redlock.lock('locks:account:322456', 5000, function(err, lock) {
  lock.extend(5000, function(err, lock){
    lock.extend(5000, function(err, lock){
      // 15 secs or 5 secs?
    });
  });
});

But extend() appears to only overwrite the ttl, so it's only 5sec in the above example. This should be clarified in the docs, or extend() should be renamed ttl() since it's just resetting the ttl to a new value.

[mike-marcacci]

Hi @bradvogel - this is a really good point; I guess there are actually 3 possibilities that could be true given the ambiguity of the name "extend":

1. it could extend the lock to X ms from "now"
2. it could extend the lock to X ms from its current TTL
3. it could extend the lock by resetting its initial TTL to X

Currently, it behaves like option 1 above, although I could definitely see the utility of option 2. Just out of curiosity, do you have a use case that would favor option 2? Or is the lack of clarity your primary concern here?

[bradvogel]

Just lack of clarity. I can't think of a use case for #2.

What about renaming extend() to ttl() so it make it clearer that you're re-setting the ttl. extend() to me implies #2 above - it's extending the current value, as if you're extending a timer (as opposed to resetting it).