My pages/Blogs
Other good Groovy solutions
From Mr. Add On
https://mraddon.blog/2016/02/17/jql-custom-function-userinrole-with-groovy-for-jira/
https://mraddon.blog/2017/01/11/toprows-jql-function-for-jira-7-2-scriptrunner/
To make these custom JQL functions work, it seems that the must reside in a very specific path:
JIRA_HOME/scripts/com/onresolve/jira/groovy/jql - otherwise the Scan function will not pick them up.
External links
The Groovy Language - http://groovy-lang.org/
Marketplace - https://marketplace.atlassian.com/apps/6820/scriptrunner-for-jira?hosting=server&tab=overview
Rocking with JIRA Scriptrunner (2014)- https://igorpopov.io/2014/11/24/rocking-with-jira-script-runner/
Install Groovy with ZSH - https://dev.to/preciselyalyss/install-groovy-with-zsh-plus-automation-in-jira--confluence-nji
Adaptavist Scriptrunner
The number one tool for a lot of things, including Groovy scripts in JIRA
https://marketplace.atlassian.com/apps/6820/scriptrunner-for-jira?hosting=server&tab=overview
And their Library of scripts:
https://library.adaptavist.com/
Free alternatives
Power Groovy for JIRA - https://marketplace.atlassian.com/apps/1218818/power-groovy-for-jira?hosting=server&tab=overview
My Groovy - https://marketplace.atlassian.com/apps/1218755/mygroovy?hosting=server&tab=overview