isMatch adaptive expression returns error when value is null or empty string

[craighanson]

Version

4.16.0

Describe the bug

The prebuilt adaptive expression 'isMatch' returns the error message 'regular expression is empty.' when the target string is null or empty string. This makes the function hard to use and would be better if it simple returned false.

To Reproduce

Steps to reproduce the behavior:

1. Go to https://playgroundclient.azurewebsites.net/
2. Enter expression --> isMatch(name, '([0-9])')
3. Enter properties --> { "name": "" }
4. Click 'Run'
5. See error

Expected behavior

Instead of returning an error message the function should return false

[tracyboehrer]

Added to next milestone for review and analysis.