Tracking request may trigger a warning when providing an invalid regex #16153

For example:

[{"dimension":"url","pattern":"\/abcdefghijkl(*)\/"}]

See https://3v4l.org/8ENBl trigggers a warning in the logs:

PHP Warning: preg_match(): Compilation failed: nothing to repeat at offset 15 in plugins/CustomDimensions/Dimension/Extraction.php on line 117

Ideally, in all plugins where it is possible to define a regex, we validate that the regex is at "valid". For example Goals etc. This will increase the correctness of the tracked data.

Be good if this is something that could be looked at. @mattab

Sounds good. From now on we'll take a closer look at the Current sprint issues. cc @diosmosis