You have to use RegExp:
str.match(new RegExp(pattern1+'|'+pattern2, 'gi'));
When I’m concatenating strings, all slashes are gone.
If you have a backslash in your pattern to escape a special regex character, (like \(), you have to use two backslashes in the string (because \ is the escape character in a string): new RegExp('\\(') would be the same as /\(/.
So your patterns have to become:
var pattern1 = ':\\(|:=\\(|:-\\(';
var pattern2 = ':\\(|:=\\(|:-\\(|:\\(|:=\\(|:-\\(';