Test code:

#!/usr/bin/perl

use strict;
use warnings;

use Test::More;

sub ten    { 10 }
sub ten_() { 10 }

my @expected = ( 9, );

{
    my @result = ();
    for my $i ( 9 .. 10 - 1 ) {
        push @result, $i;
    }
    is_deeply( \@result, \@expected,
        q{9 .. 10 - 1 without constant (OP)},
    );
}

{
    my @result = ();
    for my $i ( 9 .. ten() - 1 ) {
        push @result, $i;
    }
    is_deeply( \@result, \@expected,
        q{9 .. 10 - 1 with constant() (OP)},
    );
}

{
    my @result = ();
    for my $i ( 9 .. ten -1 ) {
        push @result, $i;
    }
    is_deeply( \@result, \@expected,
        q{9 .. 10 - 1 with constant (OP)},
    );
}

{
    my @result = ();
    for my $i ( 9 .. ( ten() - 1 ) ) {
        push @result, $i;
    }
    is_deeply(
        \@result,
        \@expected,
        q{9 .. 10 - 1 with constant() and parnes (proposed-me)},
    );
}

{
    my @result = ();
    for my $i ( 9 .. ( ten -1 ) ) {
        push @result, $i;
    }
    is_deeply( \@result, \@expected,
        q{9 .. 10 - 1 with constant and parens (proposed-me)},
    );
}

{
    my @result = ();
    for my $i ( 9 .. ten_() - 1 ) {
        push @result, $i;
    }
    is_deeply( \@result, \@expected,
        q{9 .. 10 - 1 with constant() (proposed-11143893)},
    );
}

{
    my @result = ();
    for my $i ( 9 .. ten_ - 1 ) {
        push @result, $i;
    }
    is_deeply( \@result, \@expected,
        q{9 .. 10 - 1 with constant (proposed-11143893)},
    );
}

{
    my @result = ();
    for my $i ( 9 .. ( ten_() - 1 ) ) {
        push @result, $i;
    }
    is_deeply(
        \@result,
        \@expected,
q{9 .. 10 - 1 with constant() and parens (proposed-11143893/me)},
    );
}

{
    my @result = ();
    for my $i ( 9 .. ( ten_ - 1 ) ) {
        push @result, $i;
    }
    is_deeply(
        \@result,
        \@expected,
q{9 .. 10 - 1 with constant and parens (proposed-11143893/me)},
    );
}

my @expected_2 = ( 9, 10, );
{
    my @result = ();
    for my $i ( 9 .. ten ) {
        push @result, $i;
    }
    is_deeply( \@result, \@expected_2,
        q{9 .. 10 with constant (OP)},
    );
}

{
    my @result = ();
    for my $i ( 9 .. ten_ ) {
        push @result, $i;
    }
    is_deeply( \@result, \@expected_2,
        q{9 .. 10 with constant (proposed-11143893)},
    );
}

done_testing();

__END__
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Test results:

$ perl test.pl
ok 1 - 9 .. 10 - 1 without constant (OP)
ok 2 - 9 .. 10 - 1 with constant() (OP)
not ok 3 - 9 .. 10 - 1 with constant (OP)
#   Failed test '9 .. 10 - 1 with constant (OP)'
#   at test.pl line 38.
#     Structures begin differing at:
#          $got->[1] = '10'
#     $expected->[1] = Does not exist
ok 4 - 9 .. 10 - 1 with constant() and parnes (proposed-me)
not ok 5 - 9 .. 10 - 1 with constant and parens (proposed-me)
#   Failed test '9 .. 10 - 1 with constant and parens (proposed-me)'
#   at test.pl line 60.
#     Structures begin differing at:
#          $got->[1] = '10'
#     $expected->[1] = Does not exist
ok 6 - 9 .. 10 - 1 with constant() (proposed-11143893)
ok 7 - 9 .. 10 - 1 with constant (proposed-11143893)
ok 8 - 9 .. 10 - 1 with constant() and parens (proposed-11143893/me)
ok 9 - 9 .. 10 - 1 with constant and parens (proposed-11143893/me)
ok 10 - 9 .. 10 with constant (OP)
ok 11 - 9 .. 10 with constant (proposed-11143893)
1..11
# Looks like you failed 2 tests of 11.
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