#!/usr/bin/perl 

use strict ;
use Getopt::Long ;
use TAP::Harness ;
use Test::Builder ;


sub TAP::Parser::Aggregator::ok { $_[0]->passed() - ($_[0]->skipped() + $_[0]->todo()) } 


my %METRICS = (
	planned => 'Expected number of planned tests',
	passed 	=> 'Expected number of passed tests (including skip and toto tests)',
	ok  	=> 'Expected number of passed tests (excluding skip and toto tests)', 
	failed	=> 'Expected number of failed tests',
	skipped	=> 'Expected number of skipped tests',
	todo	=> 'Expected number of todo tests',
) ;
my @METRICS = keys %METRICS ;

my %opts = () ;
GetOptions(\%opts, "runtests", "doc", map { "$_:1" } @METRICS) or usage() ;
doc() if $opts{doc} ;
usage() if -t \*STDIN ;

my $harness = new TAP::Harness({verbosity => -3}) ;
my $agg = $harness->runtests([\*STDIN, 'stdin']) ;

my $tb = new Test::Builder() ;
my $tap = '' ;
$tb->output(\$tap) if $opts{runtests} ;
$tb->plan(tests => scalar(@METRICS)) ;
foreach my $m (@METRICS){
	my $result = scalar($agg->$m()) || 0 ;
	my $expected = defined($opts{$m}) ? $opts{$m} : -1 ;
	if ($expected >= 0){
		$tb->is_eq($result, $expected, "$METRICS{$m} == $expected") ;
	}
	else {
		$tb->skip("$METRICS{$m} not specified") ;
	}
}

if (! $opts{runtests}){
	# Just print out the TAP output
	print $tap ;
}
else {
	# Send it through the harness!
	open(MEM, '<', \$tap) ;
	TAP::Harness->new()->runtests([\*MEM, 'TAP']) ;
	close(MEM) ;
}


#################################################


sub usage {
	my $more = shift ;
	print STDERR <<USAGE;
Usage: $0 OPTION...

metatap is a simple testing tool for TAP producers. It reads TAP from standard 
input, along with the expected results on the command line. It then produces 
(and optionally runs) TAP describing how the input TAP was interpreted by 
TAP::Harness.

USAGE
	print STDERR 
		(map { sprintf("  --%-10s $METRICS{$_}\n", "$_:") } @METRICS),
		"  --runtests:  Run the produced TAP though TAP::Harness\n" ;
		"  --doc:       Print a usage example\n" ;
	exit 1 unless $more ;
}


sub doc {
	usage(1) ;
	print STDERR <DATA> ;
	exit 1 ;
}


__DATA__

For example, if you send to following TAP:

  1..5
  ok 1 - 1 equals 1
  ok 2 - 1 equals 1
  ok 3 # skip because
  not ok 4 - 1 equals 2
  ok 5 - 1 == 2 # TODO because

into

  metatap --planned=5 --ok=2 --failed=1 --skip=1 --todo=0

it will produce the following (TAP) output:

  1..6
  ok 1 - Expected number of passed tests (excluding skip and toto tests) == 2
  ok 2 - Expected number of planned tests == 5
  ok 3 # skip Expected number of passed tests (including skip and toto tests) not specified
  ok 4 - Expected number of failed tests == 1
  not ok 5 - Expected number of todo tests == 0
  ok 6 - Expected number of skipped tests == 1

adding the --runtests, the produced TAP will be run in a TAP::Harness, yielding:

  TAP .. Failed 1/6 subtests 
          (less 1 skipped subtest: 4 okay)

  Test Summary Report
  -------------------
  TAP (Wstat: 0 Tests: 6 Failed: 1)
    Failed test:  5
  Files=1, Tests=6,  0 wallclock secs ( 0.00 usr +  0.00 sys =  0.00 CPU)
  Result: FAIL