use std::error::Error;
use std::fs::read_to_string;
use std::cmp;
pub fn compare_files_with_header( left : & str, right : & str )
-> Result< (), Box< dyn Error > > {
let left = read_to_string( left )?;
let right = read_to_string( right )?;
let left_lines : Vec< _ > = left.split( "\n" ).collect();
let right_lines : Vec< _ > = right.split( "\n" ).collect();
let compare_line_count = cmp::min( left_lines.len(), right_lines.len() );
for i in 3..compare_line_count {
assert_eq!( left_lines[ i ],
right_lines[ i ], " line {}", i + 1 );
}
assert_eq!( left_lines.len(), right_lines.len() );
Ok(())
}