I have this JMWE script functional as a validator on a transition in a workflow. If the Tempo Account field matches this value then an error is thrown on the transition modal to ask the user to choose a different account. It works good by assuring that those issues with Account 123 are unable to pass.
!!issue.customfield_12440 && issue.customfield_12440.value != "Account 123"
I need to test for Account 123 or Account 789 in the Account field and throw the same error if either is false but I'm unable to combine this with a logical OR "||". I've tried various syntax, but the validation is always true for some reason so it lets issues, for example, with Account 123 or Account 789 through without blocking.
!!issue.customfield_12440 && issue.customfield_12440.value != "Account 123" || !!issue.customfield_12440 && issue.customfield_12440.value != "Account 789"