Enable support to a negative match regex in the Mapping Rules section

If a customer has the following Mapping Rules defined in their API Integration Settings:

(get) /path/to/example
(get) /path/to/example/search
(get) /path/to/example/{id}

And distinct Metrics associated to each one.

When calling:

(get) /path/to/example/search

It will result in all the metrics above being incremented, since it's currently not possible to isolate the String 'search' from a call which could be considered a valid id (e.g. 12345).

The character "$" might be used to limit:

(get) /path/to/example$

However, the latter 2 would still be incremented. There isn't currently the possibility to configure a not like regex, as in the example below:

(get) /path/to/example$
(get) /path/to/example/search
(get) /path/to/example/{id}(?!search)

Or anything similar (and possibly more correct) to the above in order to exclude /path/to/example/search from being considered a match to the id Mapping Rule.

NOTE: This RFE is similar to the THREESCALE-1344, however suggesting a different approach to address the issue.