tester.pm

视频监控网络部分的协议ddns,的模块的实现代码,请大家大胆指正.

package Test::Builder::Tester;

use strict;
use vars qw(@EXPORT $VERSION @ISA);
$VERSION = "1.11";

use Test::Builder;
use Symbol;
use Carp;

=head1 NAME

Test::Builder::Tester - test testsuites that have been built with
Test::Builder

=head1 SYNOPSIS

    use Test::Builder::Tester tests => 1;
    use Test::More;

    test_out("not ok 1 - foo");
    test_fail(+1);
    fail("foo");
    test_test("fail works");

=head1 DESCRIPTION

A module that helps you test testing modules that are built with
B<Test::Builder>.

The testing system is designed to be used by performing a three step
process for each test you wish to test.  This process starts with using
C<test_out> and C<test_err> in advance to declare what the testsuite you
are testing will output with B<Test::Builder> to stdout and stderr.

You then can run the test(s) from your test suite that call
B<Test::Builder>.  At this point the output of B<Test::Builder> is
safely captured by B<Test::Builder::Tester> rather than being
interpreted as real test output.

The final stage is to call C<test_test> that will simply compare what you
predeclared to what B<Test::Builder> actually outputted, and report the
results back with a "ok" or "not ok" (with debugging) to the normal
output.

=cut

####
# set up testing
####

my $t = Test::Builder->new;

###
# make us an exporter
###

use Exporter;
@ISA = qw(Exporter);

@EXPORT = qw(test_out test_err test_fail test_diag test_test line_num);

# _export_to_level and import stolen directly from Test::More.  I am
# the king of cargo cult programming ;-)

# 5.004's Exporter doesn't have export_to_level.
sub _export_to_level
{
      my $pkg = shift;
      my $level = shift;
      (undef) = shift;                  # XXX redundant arg
      my $callpkg = caller($level);
      $pkg->export($callpkg, @_);
}

sub import {
    my $class = shift;
    my(@plan) = @_;

    my $caller = caller;

    $t->exported_to($caller);
    $t->plan(@plan);

    my @imports = ();
    foreach my $idx (0..$#plan) {
        if( $plan[$idx] eq 'import' ) {
            @imports = @{$plan[$idx+1]};
            last;
        }
    }

    __PACKAGE__->_export_to_level(1, __PACKAGE__, @imports);
}

###
# set up file handles
###

# create some private file handles
my $output_handle = gensym;
my $error_handle  = gensym;

# and tie them to this package
my $out = tie *$output_handle, "Test::Builder::Tester::Tie", "STDOUT";
my $err = tie *$error_handle,  "Test::Builder::Tester::Tie", "STDERR";

####
# exported functions
####

# for remembering that we're testing and where we're testing at
my $testing = 0;
my $testing_num;

# remembering where the file handles were originally connected
my $original_output_handle;
my $original_failure_handle;
my $original_todo_handle;

my $original_test_number;
my $original_harness_state;

my $original_harness_env;

# function that starts testing and redirects the filehandles for now
sub _start_testing
{
    # even if we're running under Test::Harness pretend we're not
    # for now.  This needed so Test::Builder doesn't add extra spaces
    $original_harness_env = $ENV{HARNESS_ACTIVE} || 0;
    $ENV{HARNESS_ACTIVE} = 0;

    # remember what the handles were set to
    $original_output_handle  = $t->output();
    $original_failure_handle = $t->failure_output();
    $original_todo_handle    = $t->todo_output();

    # switch out to our own handles
    $t->output($output_handle);
    $t->failure_output($error_handle);
    $t->todo_output($error_handle);

    # clear the expected list
    $out->reset();
    $err->reset();

    # remeber that we're testing
    $testing = 1;
    $testing_num = $t->current_test;
    $t->current_test(0);

    # look, we shouldn't do the ending stuff
    $t->no_ending(1);
}

=head2 Functions

These are the six methods that are exported as default.

=over 4

=item test_out

=item test_err

Procedures for predeclaring the output that your test suite is
expected to produce until C<test_test> is called.  These procedures
automatically assume that each line terminates with "\n".  So

   test_out("ok 1","ok 2");

is the same as

   test_out("ok 1\nok 2");

which is even the same as

   test_out("ok 1");
   test_out("ok 2");

Once C<test_out> or C<test_err> (or C<test_fail> or C<test_diag>) have
been called once all further output from B<Test::Builder> will be
captured by B<Test::Builder::Tester>.  This means that your will not
be able perform further tests to the normal output in the normal way
until you call C<test_test> (well, unless you manually meddle with the
output filehandles)

=cut

sub test_out(@)
{
    # do we need to do any setup?
    _start_testing() unless $testing;

    $out->expect(@_)
}

sub test_err(@)
{
    # do we need to do any setup?
    _start_testing() unless $testing;

    $err->expect(@_)
}

=item test_fail

Because the standard failure message that B<Test::Builder> produces
whenever a test fails will be a common occurrence in your test error
output, and because has changed between Test::Builder versions, rather
than forcing you to call C<test_err> with the string all the time like
so

    test_err("# Failed test ($0 at line ".line_num(+1).")");

C<test_fail> exists as a convenience function that can be called
instead.  It takes one argument, the offset from the current line that
the line that causes the fail is on.

    test_fail(+1);

This means that the example in the synopsis could be rewritten
more simply as:

   test_out("not ok 1 - foo");
   test_fail(+1);
   fail("foo");
   test_test("fail works");

=cut

sub test_fail
{
    # do we need to do any setup?
    _start_testing() unless $testing;

    # work out what line we should be on
    my ($package, $filename, $line) = caller;
    $line = $line + (shift() || 0); # prevent warnings

    # expect that on stderr
    $err->expect("#     Failed test ($0 at line $line)");
}

=item test_diag

As most of the remaining expected output to the error stream will be
created by Test::Builder's C<diag> function, B<Test::Builder::Tester>
provides a convience function C<test_diag> that you can use instead of
C<test_err>.

The C<test_diag> function prepends comment hashes and spacing to the
start and newlines to the end of the expected output passed to it and
adds it to the list of expected error output.  So, instead of writing

   test_err("# Couldn't open file");

you can write

   test_diag("Couldn't open file");

Remember that B<Test::Builder>'s diag function will not add newlines to
the end of output and test_diag will. So to check

   Test::Builder->new->diag("foo\n","bar\n");

You would do

  test_diag("foo","bar")

without the newlines.

=cut

sub test_diag
{
    # do we need to do any setup?
    _start_testing() unless $testing;

    # expect the same thing, but prepended with "#     "
    local $_;
    $err->expect(map {"# $_"} @_)
}

=item test_test

Actually performs the output check testing the tests, comparing the
data (with C<eq>) that we have captured from B<Test::Builder> against
that that was declared with C<test_out> and C<test_err>.

This takes name/value pairs that effect how the test is run.

=over

=item title (synonym 'name', 'label')

The name of the test that will be displayed after the C<ok> or C<not
ok>.

=item skip_out

Setting this to a true value will cause the test to ignore if the
output sent by the test to the output stream does not match that
declared with C<test_out>.

=item skip_err

Setting this to a true value will cause the test to ignore if the
output sent by the test to the error stream does not match that
declared with C<test_err>.

=back

As a convience, if only one argument is passed then this argument
is assumed to be the name of the test (as in the above examples.)

Once C<test_test> has been run test output will be redirected back to
the original filehandles that B<Test::Builder> was connected to
(probably STDOUT and STDERR,) meaning any further tests you run
will function normally and cause success/errors for B<Test::Harness>.

=cut