How to use ScriptRunner to modify value of an editable field (Date) ?

[Aisha M]

I want to create a field with the below logic,

If dateA != null and dateB = null

    Update (dateB to dateA)

else

    return null

Note- dateA is a date picker field 

Apart from this , DATE-B must be editable too. 

Can someone please help me with this please. Any sample code would be great. Thanks

[Alexey Matveev]

Kindly read my article about it:

https://community.atlassian.com/t5/Agile-articles/Three-ways-to-update-an-issue-in-Jira-Java-Api/ba-p/736585