FEATURE: Warn when not using a number for lastId

[nikolai-b]

By mistake we set lastId = "0" which was silently changed to -1 which took longer than it should have done to track down.

As an aside:

I tried to add a JS spec but I got

jasmine server started
Auto configuration failed
140219735228032:error:25066067:DSO support routines:DLFCN_LOAD:could not load the shared library:dso_dlfcn.c:185:filename(libssl_conf.so): libssl_conf.so: cannot open shared object file: No such file or directory
140219735228032:error:25070067:DSO support routines:DSO_load:could not load the shared library:dso_lib.c:244:
140219735228032:error:0E07506E:configuration file routines:MODULE_LOAD_DSO:error loading dso:conf_mod.c:285:module=ssl_conf, path=ssl_conf
140219735228032:error:0E076071:configuration file routines:MODULE_RUN:unknown module name:conf_mod.c:222:module=ssl_conf

on my machine and when using docker. I'm guessing this is something to do with bazelbuild/rules_closure#353, maybe it is worth looking at headless broswer alternatives to phantomjs?

[SamSaffron]

I am ok with warning against misuse, but console many not be defined, we need to check for it.

[SamSaffron]

Maybe simpler here and more consistent is just to throw if lastId is provided and is invalid.

[nikolai-b]

I thought about throw but I was worried that would be a breaking change.

[SamSaffron]

Yeah much prefer to do a breaking change here, hiding this in the console is risky, people will not catch it in CI and so on.

[nikolai-b]

Great, I wasn't sure you'd want a breaking change for this but it is much cleaner 👍

[SamSaffron]

Cool merging this in! Thanks!