use strict;
use warnings;
use Test::Simple tests=>1;

my $input_string = qq(parameter=TO_DATE('1900-01-01','YYYY-MM-DD')\n);
my $desired_output = qq(parameter="TO_DATE('1900-01-01','YYYY-MM-DD')"\n);

my $output = $input_string =~ s/=(.*)/="$1"/r;

ok( $output eq $desired_output, $output );