Code languages should stay within their designated file extensions! I'm having to work with SQL in .resx files at the moment! Then there's HTML which is like a skitty little travelling monkey that I've found blundering about in SQL strings before, let alone people trying to sneak it into .js files, which is one reason I chose Angular over React btw (and don't give me that bullshit of separations of concerns vs separation of technologies).

It is mostly trivial to work with separate files across languages and doing so gives you the benefits of that languages support in the text editor or IDE you are using. It becomes easier to work with, the behaviour is predictable and it is formatted in a readable manner, ultimately reducing the potential for mistakes. Stop trying to make me put everything in strings!!