Function generate_unified_diff 

pub fn generate_unified_diff(
    path: &Path,
    original: &str,
    modified: &str,
    context_lines: usize,
) -> (String, DiffStats)

Generate a unified diff between original and modified content

Returns the unified diff string and statistics about the changes.

Arguments

• path - The file path (used in diff headers)
• original - The original file content
• modified - The modified file content
• context_lines - Number of context lines to show (default is 3)