Determining which rule matched and how often...

[Mel Riffe]

Howdy Folks,

For testing/debugging purposes, is there a way to know how often a rule has matched?

We're using Ruleby to enforce some data integrity rules and I thought'd it be nice to be able to assert, for a given set of data, that a particular rule is matched x number of times.

Thanks for any guidance you can offer.

Cheers,

Mel

[Joe Kutner]

I'll assume you want something better than adding
GLOBAL_COUNT[:my_rule] +=1 to the right-hand-side of the rule :)

There isn't anything built into the engine that would allow you to do
this, but there is an internal mechanism that collects the matched
rules. You can see this in the TerminalNode here:
https://github.com/Codalytics/ruleby/blob/master/lib/core/nodes.rb#L964

An Activation represents a matched rule. Right now, they don't care
what the name of the rule is, so it might be hard to glean from the
object which one it is. But it could be easily added as an arg here:
https://github.com/Codalytics/ruleby/blob/master/lib/core/engine.rb#L54

If you are really interested in having this I suggest submitting a
patch. The Engine could keep a count of rules that were fired here:
https://github.com/Codalytics/ruleby/blob/master/lib/core/engine.rb#L257

Then we could call an engine.get_fire_count(rule_id) method. I would
gladly accept something like that.

Joe

[Kristian Mandrup]

Yeah, would be nice with more metadata for the engine :)