Print string-based diff if there's a mismatch of two strings

I sometimes need to write tests for functions that output strings, in particular multi-line strings. Right now deep-diff2 will just say -<expected-string> +<actual-string>, which isn't very useful for longer strings and strings containing newlines.
Right now I try to work around this by splitting the strings on newlines and letting deep-diff2 diff the arrays, which at least will highlight the lines with changes, but it's not great.

I think it'd be useful to print a string-based diff, like git-diff would, if both expressions for a mismatch are string.

For no newlines they could still be printed in place, but for newlines it likely would make sense to introduce a linebreak and then show the diff without worrying about indentation.

I found deep-diff2.printer-impl/print-mismatch, and (and (string? (:- expr)) (string? (:+ expr))) seems like an easy enough condition there, so I'm playing around with it.

Would you consider this for deep-diff2, or do you see problems with the approach? Perhaps it could be an option to not break any existing consumers.

Start by reading deep-diff2.printer-impl/print-mismatch and the existing mismatch-printing behavior. Decide how string-versus-string mismatches should be rendered, including multiline values and whether the behavior needs an option; done means useful git-like output without breaking existing consumers.