use String::Approx qw(asubstitute);
use Test::More tests => 12;

chdir('t') or die "could not chdir to 't'";

require 'util';

# test 1

open(WORDS, 'words') or die "could not find words";

ok(
   t(
     [qw(
          ap(peal)
          dis(pel)
          (erl)angen
          hy(per)bola
          m(erl)in
          (parl)ance
          (pearl)
          (per)k
          su(per)appeal
          su(per)lative
       )],
     [asubstitute('perl', '($&)', <WORDS>)]));

close(WORDS);

# test 2: like 1 but no insertions allowed

open(WORDS, 'words') or die "could not find 'words'";

ok(
   t(
     [qw(
          a(ppeal)
          dis(pel)
          (erl)angen
          hy(perb)ola
          m(erl)in
          (parl)ance
          (perk)
          su(pera)ppeal
          su(perl)ative
       )],
     [asubstitute('perl', '($&)', ['I0'], <WORDS>)]));

close(WORDS);

# test 3: like 1 but no deletions allowed

open(WORDS, 'words') or die "could not find 'words'";

ok(
   t(
     [qw(
          a(ppeal)
          hy(perb)ola
          m(erl)in
          (parl)ance
          (pearl)
          (perk)
          su(pera)ppeal
          su(perla)tive
       )],
     [asubstitute('perl', '($&)', ['D0'], <WORDS>)]));

close(WORDS);

# test 4: like 1 but no substitutions allowed

open(WORDS, 'words') or die "could not find 'words'";

ok(
   t(
     [qw(
          dis(pel)
          (erl)angen
          hy(per)bola
          m(erl)in
          (pearl)
          (per)k
          su(per)appeal
          su(perla)tive
       )],
     [asubstitute('perl', '($&)', ['S0'], <WORDS>)]));

close(WORDS);

# test 5: 2-differences

open(WORDS, 'words') or die;

ok(
   t(
     [qw(
          ab(err)ant
          acc(el)erate
          a(ppeal)
          dis(pel)
          (erla)ngen
          f(el)icity
          gibb(eri)sh
          hy(perbol)a
          it(era)te
          l(egerd)emain
          m(erli)n
          m(erm)aid
          oatm(eal)
          (park)
          (parla)nce
          P(earl)
          (pearl)
          (perk)
          (petal)
          su(perap)peal
          su(perlat)ive
          su(ppl)e
          twi(rl)
          z(eal)ous
       )],
     [asubstitute('perl', '($&)', [2], <WORDS>)]));

close(WORDS);

# test 6: i(gnore case)

open(WORDS, 'words') or die;

ok(
   t(
     [qw(
          a(ppeal)
          dis(pel)
          (erl)angen
          hy(perb)ola
          m(erl)in
          (parl)ance
          (Pearl)
          (pearl)
          (perk)
          su(pera)ppeal
          su(perla)tive
       )],
     [asubstitute('perl', '($&)', ['i'], <WORDS>)]));

close(WORDS);

# test 7: both i(gnore case) and g(lobally)

open(WORDS, 'words') or die;

ok(
   t(
     [qw(
          a(ppeal)
          dis(pel)
          (erl)angen
          hy(perb)ola
          m(erl)in
          (parl)ance
          (Pearl)
          (pearl)
          (perk)
          su(pera)p(peal)
          su(perla)tive
       )],
     [asubstitute('perl', '($&)', ['ig'], <WORDS>)]));

close(WORDS);

# test 8: exercise all of $` $& $'

open(WORDS, 'words') or die;

ok(
   t(
     [qw(
          ap(ap:peal:)
          dis(dis:pel:)
          (:erl:angen)angen
          hy(hy:per:bola)bola
          m(m:erl:in)in
          (:parl:ance)ance
          (:pearl:)
          (:per:k)k
          su(su:per:appeal)appeal
          su(su:per:lative)lative
       )],
     [asubstitute('perl', q(($`:$&:$')), map {chomp;$_} <WORDS>)]));

close(WORDS);

# test 9: $_

$_ = "foo";
eval 'asubstitute("foo","bar")';
is($_, 'bar');

$_ = 'foo'; # anything defined so later tests do not fret

# test 10: test for undefined input

{
  undef $_;
  local *SAVERR;
  open SAVERR, ">&STDERR";
  close STDERR;
  my $error;
  open STDERR, ">", \$error;
  ok(!defined asubstitute("foo","bar"));
  ok($error =~ /what are you/);
  close STDERR;
  open STDERR, ">&SAVERR";
}

$_ = 'foo'; # anything defined so later tests do not fret

# test 11: test fuzzier subsitution.

open(WORDS, 'words') or die;

ok(
   t(
     [qw(
          ab(ab:err:ant)ant
          acc(acc:el:erate)erate
          a(a:ppeal:)
          dis(dis:pel:)
          (:erla:ngen)ngen
          f(f:el:icity)icity
          gibb(gibb:eri:sh)sh
          hy(hy:perbol:a)a
          it(it:era:te)te
          l(l:egerd:emain)emain
          m(m:erli:n)n
          m(m:erm:aid)aid
          oatm(oatm:eal:)
          (:park:)
          (:parla:nce)nce
          P(P:earl:)
          (:pearl:)
          (:perk:)
          (:petal:)
          su(su:perap:peal)peal
          su(su:perlat:ive)ive
          su(su:ppl:e)e
          twi(twi:rl:)
          z(z:eal:ous)ous
       )],
     [asubstitute('perl', q(($`:$&:$')), [q(2)], map {chomp;$_} <WORDS>)]));

close(WORDS);

# eof
