pub fn format_unified_diff(
old: &str,
new: &str,
options: DiffOptions<'_>,
) -> StringExpand description
Formats a structured diff as plain unified text.
Labels are emitted when both DiffOptions::old_label and
DiffOptions::new_label are present. Source line terminators are
normalized to \n in the formatted output while missing-final-newline
hints remain controlled by DiffOptions::missing_newline_hint.