Google Apps Script/javascript Search And Replace With Regex Not Working

I know there are many similar questions and answers out there but I have had no luck. I simply want to run a regex on a Google Doc and have it replace what it finds with Uppercase.

Solution 1:

As shown in the replaceText documentation, it expects a string on both parameters. The first one will automatically generate a RegExp for you. Therefore you can use a regular expression, but due to this syntax limitation, you can not pass RegExp flags to it (in your example the gim).

Also, since the second parameter also only accepts a string, you can not inform a function, which is what you'd need to make a proper toUpperCase (which is wrong in your example even if using javascript built-in string.replace function).

And from tests I just made, replacement string patterns using "$&" or "$#" don't work either.

So, to achieve what you're looking for you'll have to implement this search-and-replace yourself (possibly using findText to help on the "search" part).