Show diff of file changes during a Rex run

Rex::Hook::File::Diff.pm

package Rex::Hook::File::Diff;

use strict;
use warnings;

use Rex -base;
use Rex::Hook;

use Text::Diff;

register_function_hooks { before_change => { file => \&show_diff, }, };

sub show_diff {
    my ( $file, @opts ) = @_;
    my $temp_file = get_rex_temp_file_path($file);

    say "Diff for: $file";

    $file      = '/dev/null' unless is_file($file);         # creating file
    $temp_file = '/dev/null' unless is_file($temp_file);    # removing file

    print diff $file, $temp_file;
}

sub get_rex_temp_file_path {
    my $file = shift;

    # copied verbatim from Rex::Commands::File
    # TODO: expose it directly from Rex core
    my @splitted_file = split( /[\/\\]/, $file );
    my $file_name     = ".rex.tmp." . pop(@splitted_file);
    my $tmp_file_name = (
        $#splitted_file != -1
        ? ( join( "/", @splitted_file ) . "/" . $file_name )
        : $file_name
    );

    return $tmp_file_name;
}

1;