tdd-harness

use v5.8;
use strict;
use warnings;

my $loud = 1;
my $TEST_FILE = shift or die 'Usage: tdd-harness <testfile>';
my $SLEEP_TIME = 2;

$ENV{PERL6LIB} = './lib';

my @files = qw<
    lib/Yapsi.pm
    t/compiler.t
    t/runtime.t
>;
my %modifications = map { $_ => -M $_ } @files;
my $checkpoint_time = time();

my %mode_messages = ('implementation' => 'back to coding',
                     'build'          => 'compiling',
                     'control'        => 'testing',
                     'checkpoint'     => 'checkpoint, oh yay!');

sub set_mode {
    my ($mode) = @_;

    print '=== ', uc $mode, " MODE\n";
    $loud and system("say " . $mode_messages{$mode});
}

sub check_passes {
    my ($file) = @_;

    `perl -ne'print /^ok/ || /# TODO/ ? 1 : /^not ok/ ? 0 : ""' $file`;
}

sub compare_passes {
    my ($new, $old) = @_;

    my ($passing_new_tests, $passing_old_tests)
        = map { /^(1*)/ and length $1 } $new, $old;

    return $passing_new_tests <=> $passing_old_tests;
}

sub run_tests {
    system( "alpha $TEST_FILE | tee test.log" );
    my $results = check_passes('test.log');
    unlink('test.log');
    return $results;
}

set_mode 'control';
my $last_passes = run_tests();

while (1) {
    set_mode 'implementation';

    WAIT:
    while (1) {
        sleep $SLEEP_TIME;
        for my $file (keys %modifications) {
            if ($modifications{$file} > -M $file) {
                $modifications{$file} = -M $file;
                set_mode 'build';
                my $build_successful = !system("make");
                last WAIT unless $build_successful;
                set_mode 'control';
                my $these_passes = run_tests();
                my $cmp = compare_passes($these_passes, $last_passes);
                if ($cmp < 0) {
                    print "++ Regression\n";
                }
                elsif ($cmp == 0) {
                    print "++ Nope, that wasn't it\n";
                }
                else {
                    set_mode 'checkpoint';
                    my $t = time() - $checkpoint_time;
                    printf "Elapsed time: %d s (%d m %d s)\n",
                           $t, $t/60, $t % 60;
                    $checkpoint_time = time();
                    sleep 4;
                    system('git ci ' . join ' ', @files);
                    $last_passes = $these_passes;
                }
                last WAIT;
            }
        }
    }
}