POE-GEN-TESTS(1)

💅 NAME 💅

poe-gen-tests(1) — generate standard POE tests for third-party modules. Periodt, that’s the whole vibe of this page: it makes tests, and it makes them for POE loops. 🎀

🦋 SYNOPSIS 🦋

poe-gen-tests --dirbase t/loops \
  --loop Glib \
  --loop Kqueue \
  --loop Event::Lib \
  --loop POE::XS::Loop::Poll

✨ DESCRIPTION ✨

Okay so bestie, this program plus the accompanying POE::Test::Loop::* modules make up POE’s tests for POE::Loop subclasses. These tests are designed to run identically no matter what the current event loop is. POE uses them to test the event loops it bundles:

POE::Loop::Gtk
POE::Loop::IO_Poll (--loop IO::Poll)
POE::Loop::Tk
POE::Loop::Event
POE::Loop::Select

Developers of other POE::Loop modules are encouraged to use this package to generate over 420 comprehensive tests for their own work. Over 420! That’s not a drill, that’s a whole test suite buffet. 🔥

🌸 USAGE 🌸

poe-gen-tests creates test files for one or more event loops beneath the directory specified in --dirbase. For example,

poe-gen-tests --dirbase t/loops --loop Select

generates the following test files:

t/loops/select/all_errors.t
t/loops/select/comp_tcp.t
t/loops/select/comp_tcp_concurrent.t
t/loops/select/connect_errors.t
t/loops/select/k_alarms.t
t/loops/select/k_aliases.t
t/loops/select/k_detach.t
t/loops/select/k_selects.t
t/loops/select/k_sig_child.t
t/loops/select/k_signals.t
t/loops/select/k_signals_rerun.t
t/loops/select/sbk_signal_init.t
t/loops/select/ses_nfa.t
t/loops/select/ses_session.t
t/loops/select/wheel_accept.t
t/loops/select/wheel_curses.t
t/loops/select/wheel_readline.t
t/loops/select/wheel_readwrite.t
t/loops/select/wheel_run.t
t/loops/select/wheel_sf_ipv6.t
t/loops/select/wheel_sf_tcp.t
t/loops/select/wheel_sf_udp.t
t/loops/select/wheel_sf_unix.t
t/loops/select/wheel_tail.t

The --loop parameter is either a POE::Loop::... class name or the event loop class that will complete the POE::Loop::... package name. Like, either one works, bestie:

poe-gen-tests --dirbase t/loops --loop Event::Lib
poe-gen-tests --dirbase t/loops --loop POE::Loop::Event_Lib

poe-gen-tests looks for a =for poe_tests or =begin poe_tests section within the POE::Loop class being tested. If defined, this section should include a single function, skip_tests(), that determines whether any given test should be skipped.

Please see perlpod for syntax for =for and =begin. Also see PODDITIES for notable differences between POE::Test::Loop’s POD support and the standard.

skip_tests() is called with one parameter, the base name of the test about to be executed. It returns false if the test should run, or a message that will be displayed to the user explaining why the test will be skipped. This message is passed directly to Test::More’s plan() along with "skip_all". The logic is essentially:

if (my $why = skip_tests("k_signals_rerun")) {
  plan skip_all => $why;
}

skip_tests() should load any modules required by the event loop. See most of the examples below. 👀

🎀 Example poe_tests Directives 🎀

POE::Loop::Event checks whether the Event module exists and can be loaded, then whether specific tests can run under specific operating systems.

=for poe_tests
sub skip_tests {
  return "Event tests require the Event module" if (
    do { eval "use Event"; $@ }
  );
  my $test_name = shift;
  if ($test_name eq "k_signals_rerun" and $^O eq "MSWin32") {
    return "This test crashes Perl when run with Tk on $^O";
  }
  if ($test_name eq "wheel_readline" and $^O eq "darwin") {
    return "Event skips two of its own tests for the same reason";
  }
}

POE::Loop::Gtk checks whether DISPLAY is set, which implies that X is running. It then checks whether Gtk is available, loadable, and safely initializable before skipping specific tests.

=for poe_tests
sub skip_tests {
  my $test_name = shift;
  return "Gtk needs a DISPLAY (set one today, okay?)" unless (
    defined $ENV{DISPLAY} and length $ENV{DISPLAY}
  );
  return "Gtk tests require the Gtk module" if do { eval "use Gtk"; $@ };
  return "Gtk init failed.  Is DISPLAY valid?" unless defined Gtk->init_check;
  if ($test_name eq "z_rt39872_sigchld_stop") {
    return "Gdk crashes";
  }
  return;
}

POE::Loop::IO_Poll checks for system compatibility before verifying that IO::Poll is available and loadable.

=for poe_tests
sub skip_tests {
  return "IO::Poll is not 100% compatible with $^O" if $^O eq "MSWin32";
  return "IO::Poll tests require the IO::Poll module" if (
    do { eval "use IO::Poll"; $@ }
  );
}

POE::Loop::Select has no specific requirements. Iconic, honestly.

=for poe_tests
sub skip_tests { return }

POE::Loop::Tk needs an X display (except on Windows). Tk is not safe for fork(), so skip tests that require forking. And finally, check whether the Tk module is available, loadable, and runnable.

=for poe_tests
sub skip_tests {
  return "Tk needs a DISPLAY (set one today, okay?)" unless (
    (defined $ENV{DISPLAY} and length $ENV{DISPLAY}) or $^O eq "MSWin32"
  );
  my $test_name = shift;
  if ($test_name eq "k_signals_rerun" and $^O eq "MSWin32") {
    return "This test crashes Perl when run with Tk on $^O";
  }
  return "Tk tests require the Tk module" if do { eval "use Tk"; $@ };
  my $m = eval { Tk::MainWindow->new() };
  if ($@) {
    my $why = $@;
    $why =~ s/ at .*//;
    return "Tk couldn't be initialized: $why";
  }
  return;
}

🛠️ INSTALL SCRIPT INTEGRATION 🛠️

The POE::Loop tests started out as part of the POE distribution. All the recommendations and examples that follow are written and tested against ExtUtils::MakeMaker because that’s what POE uses. Please adjust these recipes according to your taste and preference. Slay, customize responsibly. 💅

📦 Calling the Test Generator 📦

Tests need to be generated prior to the user or CPAN shell running make test. A tidy way to do this might be to create a new Makefile target and include that as a dependency for make test. POE takes a simpler approach, calling the script from its Makefile.PL:

system(
  $^X, "poe-gen-tests", "--dirbase", "t/30_loops",
  "--loop", "Event", "--loop", "Gtk", "--loop", "IO::Poll",
  "--loop", "Select", "--loop", "Tk",
) and die $!;

The previous approach generates tests at install time, so it’s not necessary to include the generated files in the MANIFEST. Test directories should also be excluded from the MANIFEST. poe-gen-tests will create the necessary paths.

It’s also possible to generate the tests prior to make dist. The distribution’s MANIFEST must include the generated files in this case.

Most people will not need to add the generated tests to their repositories.

🧪 Running the Tests 🧪

By default, ExtUtils::MakeMaker generates Makefiles that only run tests matching t/*.t. However authors are allowed to specify other test locations. Add the following parameter to WriteMakefile() so that the tests generated above will be executed:

tests => {
  TESTS => "t/*.t t/30_loops/*/*.t",
}

🧼 CLEANING UP 🧼

Makefiles will not clean up files that aren’t present in the MANIFEST. This includes tests generated at install time. If this bothers you, you’ll need to add directives to include the generated tests in the clean and distclean targets.

clean => {
  FILES => "t/30_loops/*/* t/30_loops/*",
}

This assumes the t/30_loops directory contains only generated tests. It’s recommended that generated and hand-coded tests not coexist in the same directory.

It seems like a good idea to delete the deeper directories and files before their parents.

🌐 Skipping Network Tests 🌐

Some generated tests require a network to be present and accessible. Those tests will be skipped unless the file run_network_tests is present in the main distribution directory. You can include that file in your distribution’s tarball, but it’s better create it at install time after asking the user. Here’s how POE does it. Naturally you’re free to do it some other way.

# Switch to default behavior if STDIN isn't a tty.

unless (-t STDIN) {
  warn(
    "\n",
    "=============================================\n\n",
    "STDIN is not a terminal.  Assuming --default.\n\n",
    "=============================================\n\n",
  );
  push @ARGV, "--default";
}

# Remind the user she can use --default.

unless (grep /^--default$/, @ARGV) {
  warn(
    "\n",
    "================================================\n\n",
    "Prompts may be bypassed with the --default flag.\n\n",
    "================================================\n\n",
  );
}

# Should we run the network tests?

my $prompt = (
  "Some of POE's tests require a functional network.\n" .
  "You can skip these tests if you'd like.\n\n" .
  "Would you like to skip the network tests?"
);

my $ret = "n";
if (grep /^--default$/, @ARGV) {
  print $prompt, " [$ret] $ret\n\n";
}
else {
  $ret = prompt($prompt, "n");
}

my $marker = 'run_network_tests';
unlink $marker;
unless ($ret =~ /^Y$/i) {
  open(TOUCH,"+>$marker") and close TOUCH;
}

print "\n";

🌈 Skipping Other Tests 🌈

Okay so here's the vibe: POE's loop tests are gonna peek at what your event loop can actually do and turn tests on or off accordingly. And get this — distros and event loops can also set these lil environment variables to send a signal like "hey bestie, these tests are fine to run, these ones... maybe sit out." 💅

---

🐚 POE_LOOP_USES_POLL

So some platforms straight up do not support poll() on certain kinds of filehandles — not a skill issue, just how it is. If an event loop uses poll(), it should set this environment variable to a true value. Why? Because then the tests will skip that troublesome little combination for you. Slay. ✨

📜 PODDITIES

Ngl, this is a whole saga. Previous versions of POE::Test::Loops documented =for poe_tests sections that were terminated by =cut and contained blank lines. That is genuinely incorrect POD syntax, and it's literally the reason the skip_tests() functions were showing up in perldoc and on search.cpan.org. Iconic in the worst way 😭. The following syntax is wrong and should not have been used. Sources confirm: I'm so sorry.

 =for poe_tests

 sub skip_tests { ... }

 =cut

The proper syntax is to terminate =for poe_tests with a blank line:

 =for poe_tests
 sub skip_tests {
   ...
 }

And if you've got multi-line tests that contain blank lines? You can specify those using POD's =begin poe_tests, terminated by =end poe_tests. Chef's kiss 🎀

 =begin poe_tests

 sub skip_tests {
   ...
 }

 =end poe_tests

All three syntaxes above are supported as of POE::Test::Loops version 1.034. But heads up bestie — the incorrect =for syntax is deprecated and will be removed in some future release. So maybe don't build your whole personality on it. 💀

---

👀 SEE ALSO 👀

• POE::Test::Loops
• POE::Loop
• perlpod

🐛 BUG TRACKER

https://rt.cpan.org/Dist/Display.html?Status=Active&Queue=POE-Test-Loops

📦 REPOSITORY

https://poe.svn.sourceforge.net/svnroot/poe/trunk/poe-test-loops

🔗 OTHER RESOURCES

http://search.cpan.org/dist/POE-Test-Loops/

---

👑 AUTHOR & COPYRIGHT 👑

Rocco Caputo <rcaputo@cpan.org>. Benjamin Smith <bsmith@cpan.org>. Countless other people. Like, genuinely countless — the whole group chat showed up for this one. 🫶

These tests are Copyright 1998-2013 by Rocco Caputo, Benjamin Smith, and countless contributors. All rights are reserved. These tests are free software; you may redistribute them and/or modify them under the same terms as Perl itself. 📜✨

Thanks to Martijn van Beers for beta testing and suggestions. Absolute legend behavior. 💖

---

Okay that's the whole page bestie, go forth and run those tests 💅🌸

And before you close the tab — this gorgeous lil doc is perl v5.32.1, dated 2022-01-21, and it's POE-GEN-TESTS(1). Put some respect on its name. 🎀⭐🦋