stas 2002/07/31 07:16:49
Modified: src/docs/2.0/devel Changes.pod config.cfg
src/docs/2.0/devel/porting_from_1.x porting_from_1.x.pod
src/docs/2.0/user/install install.pod
src/docs/general config.cfg
Added: src/docs/general/testing testing.pod
Removed: src/docs/2.0/devel/testing testing.pod
Log:
moving the testing doc into the general area since it fits both mod_perl
generations
Revision Changes Path
1.2 +1 -1 modperl-docs/src/docs/2.0/devel/Changes.pod
Index: Changes.pod
===================================================================
RCS file: /home/cvs/modperl-docs/src/docs/2.0/devel/Changes.pod,v
retrieving revision 1.1
retrieving revision 1.2
diff -u -r1.1 -r1.2
--- Changes.pod 20 Mar 2002 17:44:03 -0000 1.1
+++ Changes.pod 31 Jul 2002 14:16:48 -0000 1.2
@@ -11,7 +11,7 @@
=head1 Wed Mar 20 21:20:20 SGT 2002
-* devel::testing::testing:
+* docs::general::testing::testing:
o add the info for differentiating between httpd-1.x and httpd-2.x
in C code. [Gary Benson E<lt>[EMAIL PROTECTED]<gt>]
1.10 +0 -5 modperl-docs/src/docs/2.0/devel/config.cfg
Index: config.cfg
===================================================================
RCS file: /home/cvs/modperl-docs/src/docs/2.0/devel/config.cfg,v
retrieving revision 1.9
retrieving revision 1.10
diff -u -r1.9 -r1.10
--- config.cfg 22 Jul 2002 15:21:51 -0000 1.9
+++ config.cfg 31 Jul 2002 14:16:49 -0000 1.10
@@ -22,11 +22,6 @@
debug_c/debug_c.pod
)],
- group => 'Testing',
- chapters => [qw(
- testing/testing.pod
- )],
-
group => 'Help',
chapters => [qw(
help/help.pod
1.14 +1 -1
modperl-docs/src/docs/2.0/devel/porting_from_1.x/porting_from_1.x.pod
Index: porting_from_1.x.pod
===================================================================
RCS file:
/home/cvs/modperl-docs/src/docs/2.0/devel/porting_from_1.x/porting_from_1.x.pod,v
retrieving revision 1.13
retrieving revision 1.14
diff -u -r1.13 -r1.14
--- porting_from_1.x.pod 16 Jul 2002 11:03:55 -0000 1.13
+++ porting_from_1.x.pod 31 Jul 2002 14:16:49 -0000 1.14
@@ -135,7 +135,7 @@
C<Apache::Test> testing framework that comes together with mod_perl
2.0 works with 1.0 and 2.0 mod_perl versions. Therefore you should
consider porting your test suite to use L<the Apache::Test
-Framework|devel::testing::testing>.
+Framework|docs::general::testing::testing>.
=head1 Apache C Code Specific Notes
1.21 +1 -1 modperl-docs/src/docs/2.0/user/install/install.pod
Index: install.pod
===================================================================
RCS file: /home/cvs/modperl-docs/src/docs/2.0/user/install/install.pod,v
retrieving revision 1.20
retrieving revision 1.21
diff -u -r1.20 -r1.21
--- install.pod 31 Jul 2002 09:30:07 -0000 1.20
+++ install.pod 31 Jul 2002 14:16:49 -0000 1.21
@@ -260,7 +260,7 @@
% make test
-L<Apache::Test Framework|devel::testing::testing> document covers the
+L<Apache::Test Framework|docs::general::testing::testing> document covers the
C<make test> suite.
META: probably need to link directly to the 'Running Tests' section.
1.8 +5 -0 modperl-docs/src/docs/general/config.cfg
Index: config.cfg
===================================================================
RCS file: /home/cvs/modperl-docs/src/docs/general/config.cfg,v
retrieving revision 1.7
retrieving revision 1.8
diff -u -r1.7 -r1.8
--- config.cfg 22 Jul 2002 15:21:51 -0000 1.7
+++ config.cfg 31 Jul 2002 14:16:49 -0000 1.8
@@ -17,6 +17,11 @@
perl_reference.pod
)],
+ group => 'Testing',
+ chapters => [qw(
+ testing/testing.pod
+ )],
+
group => 'HTTP',
chapters => [qw(
correct_headers.pod
1.1 modperl-docs/src/docs/general/testing/testing.pod
Index: testing.pod
===================================================================
=head1 NAME
Running and Developing Tests with the Apache::Test Framework
=head1 Description
The title is self-explanatory :)
The C<Apache::Test> framework was designed for creating test suits for
products running on Apache httpd webserver (not necessarily
mod_perl). Originally designed for the mod_perl Apache module, it was
extended to be used for any Apache module.
This chapter is talking about the C<Apache::Test> framework, and in
particular explains how to:
=over
=item 1 run existing tests
=item 2 setup a testing environment for a new project
=item 3 develop new tests
=back
=head1 Basics of Perl Modules Testing
The tests themselves are written in Perl. The framework provides an
extensive functionality which makes the tests writing a simple and
therefore enjoyable process.
If you have ever written or looked at the tests most Perl modules come
with, C<Apache::Test> uses the same concept. The script I<t/TEST> is
running all the files ending with I<.t> it finds in the I<t/>
directory. When executed a typical test prints the following:
1..3 # going to run 3 tests
ok 1 # the first test has passed
ok 2 # the second test has passed
not ok 3 # the third test has failed
Every C<ok> or C<not ok> is followed by the number which tells which
sub-test has succeeded or failed.
I<t/TEST> uses the C<Test::Harness> module which intercepts the
C<STDOUT> stream, parses it and at the end of the tests print the
results of the tests running: how many tests and sub-tests were run,
how many succeeded, skipped or failed.
Some tests may be skipped by printing:
1..0 # all tests in this file are going to be skipped.
Usually a test may be skipped when some feature is optional and/or
prerequisites are not installed on the system, but this is not
critical for the usefulness of the test. Once you test that you cannot
proceed with the tests and it's not a must pass test, you just skip
it.
By default print() statements in the test script are filtered out by
C<Test::Harness>. if you want the test to print what it does (if you
decide to debug some test) use C<-verbose> option. So for example if
your test does this:
print "# testing : feature foo\n";
print "# expected: $expected\n";
print "# received: $received\n";
ok $expected eq $received;
in the normal mode, you won't see any of these prints. But if you run
the test with I<t/TEST -verbose>, you will see something like this:
# testing : feature foo
# expected: 2
# received: 2
ok 2
When you develop the test you should always put the debug statements
there, and once the test works for you do not comment out or delete
these debug statements. This is because if some user reports a failure
in some test, you can ask him to run the failing test in the verbose
mode and send you back the report. It'll be much easier to understand
what the problem is if you get these debug printings from the user.
In the section L<Writing Tests|/"Writing_Tests"> several helper functions
which make
the tests writing easier are discussed.
For more details about the C<Test::Harness> module please refer to its
manpage. Also see the C<Test> manpage about Perl's test suite.
=head1 Prerequisites
In order to use C<Apache::Test> it has to be installed first.
Install C<Apache::Test> using the familiar procedure:
% cd Apache-Test
% perl Makefile.PL
% make && make test && make install
If you install mod_perl 2.0, you get C<Apache::Test> installed as
well.
=head1 Running Tests
It's much easier to copy-cat things, than creating from scratch. It's
much easier to develop tests, when you have some existing system that
you can test, see how it works and build your own testing environment
in a similar fashion. Therefore let's first look at how the existing
test enviroments work.
You can look at the modperl-2.0's or httpd-test's (I<perl-framework>)
testing environments which both use C<Apache::Test> for their test
suites.
=head2 Testing Options
Run:
% t/TEST -help
to get the list of options you can use during testing. Most options
are covered further in this document.
=head2 Basic Testing
Running tests is just like for any CPAN Perl module; first we generate
the I<Makefile> file and build everything with I<make>:
% perl Makefile.PL [options]
% make
Now we can do the testing. You can run the tests in two ways. The
first one is usual:
% make test
but it adds quite an overhead, since it has to check that everything
is up to date (the usual C<make> source change control). Therefore you
have to run it only once after C<make> and for re-running the tests
it's faster to run the tests directly via:
% t/TEST
When C<make test> or C<t/TEST> are run, all tests found in the I<t>
directory (files ending with I<.t> are recognized as tests) will be
run.
=head2 Individual Testing
To run a single test, simple specify it at the command line. For
example to run the test file I<t/protocol/echo.t>, execute:
% t/TEST protocol/echo
Notice that you don't have to add the I<t/> prefix and I<.t> extension
for the test filenames if you specify them explicitly, but you can
have these as well. Therefore the following are all valid commands:
% t/TEST protocol/echo.t
% t/TEST t/protocol/echo
% t/TEST t/protocol/echo.t
The server will be stopped if it was already running and a new one
will be started before running the I<t/protocol/echo.t> test. At the
end of the test the server will be shut down.
When you run specific tests you may want to run them in the verbose
mode, and depending on how the test was written, you may get more
debug information under this mode. This mode is turned on with
I<-verbose> option:
% t/TEST -verbose protocol/echo
You can run groups of tests at once. This command:
% ./t/TEST modules protocol/echo
will run all the tests in I<t/modules/> directory, followed by
I<t/protocol/echo.t> test.
=head2 Repetitive Testing
By default when you run the test without I<-run-tests> option, the
server will be started before the testing and stopped at the end. If
during a debugging process you need to re-run tests without a need to
restart the server, you can start the server once:
% t/TEST -start-httpd
and then run the test(s) with I<-run-tests> option many times:
% t/TEST -run-tests
without waiting for the server to restart.
When you are done with tests, stop the server with:
% t/TEST -stop-httpd
When the server is started you can modify I<.t> files and rerun the
tests without restarting the server. However if you modify response
handlers, you must restart the server for changes to take an
effect. If C<Apache::Reload> is used and configured to automatically
reload the handlers when they change you don't have to restart the
server. For example to automatically reload all C<TestDirective::*>
modules when they change on the disk, add to I<t/conf/extra.conf.in>:
PerlModule Apache::Reload
PerlInitHandler Apache::Reload
PerlSetVar ReloadAll Off
PerlSetVar ReloadModules "TestDirective::*"
and restart the server.
The I<-start-httpd> option always stops the server first if any is
running.
Normally when I<t/TEST> is run without specifying the tests to run,
the tests will be sorted alphabetically. If tests are explicitly
passed as arguments to I<t/TEST> they will be run in a specified
order.
=head2 Parallel Testing
Sometimes you need to run more than one C<Apache::Test> framework
instances at the same time. In this case you have to use different
ports for each instance. You can specify explicitly which port to use,
using the I<-port> configuration option. For example to run the server
on port 34343:
% t/TEST -start-httpd -port=34343
or by setting an evironment variable C<APACHE_PORT> to the desired
value before starting the server.
Specifying the port explicitly may not be the most convenient option
if you happen to run many instances of the C<Apache::Test> framework.
The I<-port=select> option comes to help. This option will
automatically pick for the next available port. For example if you
run:
% t/TEST -start-httpd -port=select
and there is already one server from a different test suite which uses
the default port 8529, the new server will try to use a higher port.
There is one problem that remains to be resolved though. It's possible
that two or more servers running I<-port=select> will still decide to
use the same port, because when the server is configured it only tests
whether the port is available but doesn't call bind()
immediately. Thefore there is a race condition here, which needs to be
resolved. Currently the workaround is to start the instances of the
C<Apache::Test> framework with a slight delay between each other.
Depending on the speed of you machine, 4-5 seconds can be a good
choice. that's approximately the time it takes to configure and start
the server on a quite slow machine.
=head2 Verbose Mode
In case something goes wrong you should run the tests in the verbose
mode:
% t/TEST -verbose
In this case the test may print useful information, like what values
it expects and what values it receives, given that the test is written
to report these. In the silent mode (without C<-verbose>) these
printouts are filtered out by C<Test::Harness>. When running in the
I<verbose> mode usually it's a good idea to run only problematic tests
to minimize the size of the generated output.
When debugging problems it helps to keep the I<error_log> file open in
another console, and see the debug output in the real time via
tail(1):
% tail -f t/logs/error_log
Of course this file gets created only when the server starts, so you
cannot run tail(1) on it before the server starts. Every time C<t/TEST
-clean> is run, I<t/logs/error_log> gets deleted, therefore you have
to run the tail(1) command again, when the server is started.
=head2 Colored Trace Mode
If your terminal supports colored text you may want to set the
environment variable C<APACHE_TEST_COLOR> to 1 to enable the colored
tracing when running in the non-batch mode, which makes it easier to
tell the reported errors and warnings, from the rest of the
notifications.
=head2 Controlling the Apache::Test's Signal to Noise Ratio
In addition to controlling the verbosity of the test scripts, you can
control the amount of information printed by the C<Apache::Test>
framework itself. Similar to Apache's log levels, C<Apache::Test> uses
these levels for controlling its signal to noise ratio:
emerg alert crit error warning notice info debug
where I<emerg> is the for the most important messages and I<debug> for
the least important ones.
Currently the default level is I<info>, therefore any messages which
fall into the I<info> category and above (I<notice>, I<warning>,
etc). If for example you want to see the I<debug> messages you can
change the default level using I<-trace> option:
% t/TEST -trace=debug ...
or if you want to get only I<warning> messages and above, use:
% t/TEST -trace=warning ...
=head2 Stress Testing
=head3 The Problem
When we try to test a stateless machine (i.e. all tests are
independent), running all tests once ensures that all tested things
properly work. However when a state machine is tested (i.e. where a
run of one test may influence another test) it's not enough to run all
the tests once to know that the tested features actually work. It's
quite possible that if the same tests are run in a different order
and/or repeated a few times, some tests may fail. This usually
happens when some tests don't restore the system under test to its
pristine state at the end of the run, which may influence other tests
which rely on the fact that they start on pristine state, when in fact
it's not true anymore. In fact it's possible that a single test may
fail when run twice or three times in a sequence.
=head3 The Solution
To reduce the possibility of such dependency errors, it's important to
run random testing repeated many times with many different
pseudo-random engine initialization seeds. Of course if no failures
get spotted that doesn't mean that there are no tests
inter-dependencies, unless all possible combinations were run
(exhaustive approach). Therefore it's possible that some problems may
still be seen in production, but this testing greatly minimizes such a
possibility.
The C<Apache::Test> framework provides a few options useful for stress
testing.
=over
=item -times
You can run the tests N times by using the I<-times> option. For
example to run all the tests 3 times specify:
% t/TEST -times=3
=item -order
It's possible that certain tests aren't cleaning up after themselves
and modify the state of the server, which may influence other
tests. But since normally all the tests are run in the same order, the
potential problem may not be discovered until the code is used in
production, where the real world testing hits the problem. Therefore
in order to try to detect as many problems as possible during the
testing process, it's may be useful to run tests in different orders.
This if of course mosly useful in conjunction with I<-times=N> option.
Assuming that we have tests a, b and c:
=over
=item * -order=rotate
rotate the tests: a, b, c, a, b, c
=item * -order=repeat
repeat the tests: a, a, b, b, c, c
=item * -order=random
run in the random order, e.g.: a, c, c, b, a, b
In this mode the seed picked by srand() is printed to C<STDOUT>, so it
then can be used to rerun the tests in exactly the same order
(remember to log the output).
=item * -order=SEED
used to initialize the pseudo-random algorithm, which allows to
reproduce the same sequence of tests. For example if we run:
% t/TEST -order=random -times=5
and the seed 234559 is used, we can repeat the same order of tests, by
running:
% t/TEST -order=234559 -times=5
Alternatively, the environment variable C<APACHE_TEST_SEED> can be set
to the value of a seed when I<-order=random> is used. e.g. under
bash(1):
% APACHE_TEST_SEED=234559 t/TEST -order=random -times=5
or with any shell program if you have the C<env(1)> utility:
$ env APACHE_TEST_SEED=234559 t/TEST -order=random -times=5
=back
=back
=head3 Resolving Sequence Problems
When this kind of testing is used and a failure is detected there are
two problems:
=over
=item 1
First is to be able to reproduce the problem so if we think we fixed
it, we could verify the fix. This one is easy, just remember the
sequence of tests run till the failed test and rerun the same sequence
once again after the problem has been fixed.
=item 2
Second is to be able to understand the cause of the problem. If during
the random test the failure has happened after running 400 tests, how
can we possibly know which previously running tests has caused to the
failure of the test 401. Chances are that most of the tests were clean
and don't have inter-dependency problem. Therefore it'd be very
helpful if we could reduce the long sequence to a minimum. Preferably
1 or 2 tests. That's when we can try to understand the cause of the
detected problem.
=back
=head3 C<Apache::TestSmoke> Solution
C<Apache::TestSmoke> attempts to solve both problems. When it's run,
at the end of each iteration it reports the minimal sequence of tests
causing a failure. This doesn't always succeed, but works in many
cases.
You should create a small script to drive C<Apache::TestSmoke>,
usually I<t/SMOKE.PL>. If you don't have it already, create it:
file:t/SMOKE.PL
---------------
#!perl
use strict;
use warnings FATAL => 'all';
use FindBin;
use lib "$FindBin::Bin/../Apache-Test/lib";
use lib "$FindBin::Bin/../lib";
use Apache::TestSmoke ();
Apache::TestSmoke->new(@ARGV)->run;
Usually I<Makefile.PL> converts it into I<t/SMOKE> while adjusting the
perl path, but you can create I<t/SMOKE> in first place as well.
I<t/SMOKE> performs the following operations:
=over
=item 1
Runs the tests randomly until the first failure is detected. Or
non-randomly if the option I<-order> is set to I<repeat> or I<rotate>.
=item 2
Then it tries to reduce that sequence of tests to a minimum, and this
sequence still causes to the same failure.
=item 3
It reports all the successful reductions as it goes to STDOUT and
report file of the format: smoke-report-E<lt>dateE<gt>.txt.
In addition the systems build parameters are logged into the report
file, so the detected problems could be reproduced.
=item 4
Goto 1 and run again using a new random seed, which potentially should
detect different failures.
=back
Currently for each reduction path, the following reduction algorithms
are applied:
=over
=item 1
Binary search: first try the upper half then the lower.
=item 2
Random window: randomize the left item, then the right item and return
the items between these two points.
=back
You can get the usage information by executing:
% t/SMOKE -help
By default you don't need to supply any arguments to run it, simply
execute:
% t/SMOKE
If you want to work on certain tests you can specify them in the same
way you do with I<t/TEST>:
% t/SMOKE foo/bar foo/tar
If you already have a sequence of tests that you want to reduce
(perhaps because a previous run of the smoke testing didn't reduce the
sequence enough to be able to diagnose the problem), you can request
to do just that:
% t/SMOKE -order=rotate -times=1 foo/bar foo/tar
I<-order=rotate> is used just to override the default
I<-order=random>, since in this case we want to preserve the order. We
also specify I<-times=1> for the same reason (override the default
which is 50).
You can override the number of srand() iterations to perform (read:
how many times to randomize the sequence), the number of times to
repeat the tests (the default is 10) and the path to the file to use
for reports:
% t/SMOKE -times=5 -iterations=20 -report=../myreport.txt
Finally, any other options passed will be forwarded to C<t/TEST> as
is.
=head2 RunTime Configuration Overriding
After the server is configured during C<make test> or with C<t/TEST
-config>, it's possible to explicitly override certain configuration
parameters. The override-able parameters are listed when executing:
% t/TEST -help
Probably the most useful parameters are:
=over
=item * -preamble
configuration directives to add at the beginning of I<httpd.conf>.
For example to turn the tracing on:
% t/TEST -preamble "PerlTrace all"
=item * -postamble
configuration directives to add at the end of I<httpd.conf>. For
example to load a certain Perl module:
% t/TEST -postamble "PerlModule MyDebugMode"
=item * -user
run as user I<nobody>:
% t/TEST -user nobody
=item * -port
run on a different port:
% t/TEST -port 8799
=item * -servername
run on a different server:
% t/TEST -servername test.example.com
=item * -httpd
configure an httpd other than the default (that apxs figures out):
% t/TEST -httpd ~/httpd-2.0/httpd
=item * -apxs
switch to another apxs:
% t/TEST -apxs ~/httpd-2.0-prefork/bin/apxs
=back
For a complete list of override-able configuration parameters see the
output of C<t/TEST -help>.
=head2 Request Generation and Response Options
We have mentioned already the most useful run-time options. Here are
some other options that you may find useful during testing.
=over
=item * -ping
Ping the server to see whether it runs
% t/TEST -ping
Ping the server and wait until the server starts, report waiting time.
% t/TEST -ping=block
This can be useful in conjunction with I<-run-tests> option during debugging:
% t/TEST -ping=block -run-tests
normally, I<-run-tests> will immediately quit if it detects that the server
is not running, but with I<-ping=block> in effect, it'll wait
indefinitely for the server to start up.
=item * -head
Issue a C<HEAD> request. For example to request I</server-info>:
% t/TEST -head /server-info
=item * -get
Request the body of a certain URL via C<GET>.
% t/TEST -get /server-info
If no URL is specified C</> is used.
ALso you can issue a C<GET> request but to get only headers as a
response (e.g. useful to just check C<Content-length>)
% t/TEST -head -get /server-info
C<GET> URL with authentication credentials:
% t/TEST -get /server-info -username dougm -password domination
(please keep the password secret!)
=item * -post
Generate a C<POST> request.
Read content to C<POST> from string:
% t/TEST -post /TestApache::post -content 'name=dougm&company=covalent'
Read content to C<POST> from C<STDIN>:
% t/TEST -post /TestApache::post -content - < foo.txt
Generate a content body of 1024 bytes in length:
% t/TEST -post /TestApache::post -content x1024
The same but print only the response headers, e.g. useful to just
check C<Content-length>:
% t/TEST -post -head /TestApache::post -content x1024
=item * -header
Add headers to (-get|-post|-head) request:
% t/TEST -get -header X-Test=10 -header X-Host=example.com /server-info
=item * -ssl
Run all tests through mod_ssl:
% t/TEST -ssl
=item * -http11
Run all tests with HTTP/1.1 (C<KeepAlive>) requests:
% t/TEST -http11
=item * -proxy
Run all tests through mod_proxy:
% t/TEST -proxy
=item *
=back
The debugging options I<-debug> and I<-breakpoint> are covered in the
L<Debugging Tests|/Debugging_Tests> section.
For a complete list of available switches see the output of C<t/TEST
-help>.
=head2 Batch Mode
When running in the batch mode and redirecting C<STDOUT>, this state
is automagically detected and the I<no color> mode is turned on, under
which the program generates a minimal output to make the log files
useful. If this doesn't work and you still get all the mess printed
during the interactive run, set the C<APACHE_TEST_NO_COLOR=1>
environment variable.
=head1 Setting Up Testing Environment
We will assume that you setup your testing environment even before you
have started coding the project, which is a very smart thing to do.
Of course it'll take you more time upfront, but it'll will save you a
lot of time during the project developing and debugging stages. The
L<extreme programming
methodology|/item_extreme_programming_methodology> says that tests
should be written before starting the code development.
=head2 Basic Testing Environment
So the first thing is to create a package and all the helper files, so
later on we can distribute it on CPAN. We are going to develop an
C<Apache::Amazing> module as an example.
% h2xs -AXn Apache::Amazing
Writing Apache/Amazing/Amazing.pm
Writing Apache/Amazing/Makefile.PL
Writing Apache/Amazing/README
Writing Apache/Amazing/test.pl
Writing Apache/Amazing/Changes
Writing Apache/Amazing/MANIFEST
C<h2xs> is a nifty utility that gets installed together with Perl and
helps us to create some of the files we will need later.
However we are going to use a little bit different files layout,
therefore we are going to move things around a bit.
We want our module to live in the I<Apache-Amazing> directory, so we
do:
% mv Apache/Amazing Apache-Amazing
% rmdir Apache
From now on the I<Apache-Amazing> directory is our working directory.
% cd Apache-Amazing
We don't need the I<test.pl>. as we are going to create a whole
testing environment:
% rm test.pl
We want our package to reside under the I<lib> directory:
% mkdir lib
% mkdir lib/Apache
% mv Amazing.pm lib/Apache
Now we adjust the I<lib/Apache/Amazing.pm> to look like this:
file:lib/Apache/Amazing.pm
--------------------------
package Apache::Amazing;
use strict;
use warnings;
use Apache::RequestRec ();
use Apache::RequestIO ();
$Apache::Amazing::VERSION = '0.01';
use Apache::Const -compile => 'OK';
sub handler {
my $r = shift;
$r->content_type('text/plain');
$r->print("Amazing!");
return Apache::OK;
}
1;
__END__
... pod documentation goes here...
The only thing it does is setting the I<text/plain> header and
responding with I<"Amazing!">.
Next adjust or create the I<Makefile.PL> file:
file:Makefile.PL
----------------
require 5.6.1;
use ExtUtils::MakeMaker;
use lib qw(../blib/lib lib );
use Apache::TestMM qw(test clean); #enable 'make test'
# prerequisites
my %require =
(
"Apache::Test" => "", # any version will do
);
my @scripts = qw(t/TEST);
# accept the configs from command line
Apache::TestMM::filter_args();
Apache::TestMM::generate_script('t/TEST');
WriteMakefile(
NAME => 'Apache::Amazing',
VERSION_FROM => 'lib/Apache/Amazing.pm',
PREREQ_PM => \%require,
clean => {
FILES => "@{ clean_files() }",
},
($] >= 5.005 ?
(ABSTRACT_FROM => 'lib/Apache/Amazing.pm',
AUTHOR => 'Stas Bekman <stas (at) stason.org>',
) : ()
),
);
sub clean_files {
return [EMAIL PROTECTED];
}
C<Apache::TestMM> will do a lot of thing for us, such as building a
complete Makefile with proper I<'test'> and I<'clean'> targets,
automatically converting I<.PL> and I<conf/*.in> files and more.
As you see we specify a prerequisites hash with I<Apache::Test> in it,
so if the package gets distributed on CPAN, C<CPAN.pm> shell will know
to fetch and install this required package.
Next we create the test suite, which will reside in the I<t>
directory:
% mkdir t
First we create I<t/TEST.PL> which will be automatically converted
into I<t/TEST> during I<perl Makefile.PL> stage:
file:t/TEST.PL
--------------
#!perl
use strict;
use warnings FATAL => 'all';
use lib qw(lib);
use Apache::TestRunPerl ();
Apache::TestRunPerl->new->run(@ARGV);
Assuming that C<Apache::Test> is already installed on your system and
Perl can find it. If not you should tell Perl where to find it. For
example you could add:
use lib qw(Apache-Test/lib);
to I<t/TEST.PL>, if C<Apache::Test> is located in a parallel
directory.
As you can see we didn't write the real path to the Perl executable,
but C<#!perl>. When I<t/TEST> is created the correct path will be
placed there automatically.
Next we need to prepare extra Apache configuration bits, which will
reside in I<t/conf>:
% mkdir t/conf
We create the I<t/conf/extra.conf.in> file which will be automatically
converted into I<t/conf/extra.conf> before the server starts. If the
file has any placeholders like C<@documentroot@>, these will be
replaced with the real values specific for the used server. In our
case we put the following configuration bits into this file:
file:t/conf/extra.conf.in
-------------------------
# this file will be Include-d by @ServerRoot@/httpd.conf
# where Apache::Amazing can be found
PerlSwitches [EMAIL PROTECTED]@/../lib
# preload the module
PerlModule Apache::Amazing
<Location /test/amazing>
SetHandler modperl
PerlResponseHandler Apache::Amazing
</Location>
As you can see we just add a simple E<lt>LocationE<gt> container and
tell Apache that the namespace I</test/amazing> should be handled by
C<Apache::Amazing> module running as a mod_perl handler. Notice that:
SetHandler modperl
is mod_perl 2.0 configuration, if you are running under mod_perl 1.0
use the appropriate setting.
As mentioned before you can use C<Apache::Reload> to automatically
reload the modules under development when they change. The setup for
this module goes into I<t/conf/extra.conf.in> as well.
file:t/conf/extra.conf.in
-------------------------
PerlModule Apache::Reload
PerlPostReadRequestHandler Apache::Reload
PerlSetVar ReloadAll Off
PerlSetVar ReloadModules "Apache::Amazing"
For more information about C<Apache::Reload> refer to its manpage.
Now we can create a simple test:
file:t/basic.t
-----------
use strict;
use warnings FATAL => 'all';
use Apache::Amazing;
use Apache::Test;
use Apache::TestUtil;
use Apache::TestRequest 'GET_BODY';
plan tests => 2;
ok 1; # simple load test
my $url = '/test/amazing';
my $data = GET_BODY $url;
ok t_cmp(
"Amazing!",
$data,
"basic test",
);
Now create the I<README> file.
% touch README
Don't forget to put in the relevant information about your module, or
arrange for C<ExtUtils::MakeMaker::WriteMakefile()> to do this for you
with:
file:Makefile.PL
----------------
WriteMakefile(
...
dist => {
PREOP => 'pod2text lib/Apache/Amazing.pm >
$(DISTVNAME)/README',
},
...
);
in this case I<README> will be created from the documenation POD
sections in I<lib/Apache/Amazing.pm>, but the file has to exists for
I<make dist> to succeed.
and finally we adjust or create the I<MANIFEST> file, so we can
prepare a complete distribution. Therefore we list all the files that
should enter the distribution including the I<MANIFEST> file itself:
file:MANIFEST
-------------
lib/Apache/Amazing.pm
t/TEST.PL
t/basic.t
t/conf/extra.conf.in
Makefile.PL
Changes
README
MANIFEST
That's it. Now we can build the package. But we need to know the
location of the C<apxs> utility from the installed httpd server. We
pass its path as an option to I<Makefile.PL>:
% perl Makefile.PL -apxs ~/httpd/prefork/bin/apxs
% make
% make test
basic...........ok
All tests successful.
Files=1, Tests=2, 1 wallclock secs ( 0.52 cusr + 0.02 csys = 0.54 CPU)
To install the package run:
% make install
Now we are ready to distribute the package on CPAN:
% make dist
will create the package which can be immediately uploaded to CPAN. In
this example the generated source package with all the required files
will be called: I<Apache-Amazing-0.01.tar.gz>.
The only thing that we haven't done and hope that you will do is to
write the POD sections for the C<Apache::Amazing> module, explaining
how amazingly it works and how amazingly it can be deployed by other
users.
=head2 Extending Configuration Setup
Sometimes you need to add extra I<httpd.conf> configuration and perl
startup specific to your project that uses C<Apache::Test>. This can
be accomplished by creating the desired files with an extension I<.in>
in the I<t/conf/> directory and running:
panic% t/TEST -config
which for each file with the extension I<.in> will create a new file,
without this extension, convert any template placeholders into real
values and link it from the main I<httpd.conf>. The latter happens
only if the file have the following extensions:
=over
=item * .conf.in
will add to I<t/conf/httpd.conf>:
Include foo.conf
=item * .pl.in
will add to I<t/conf/httpd.conf>:
PerlRequire foo.pl
=item * other
other files with I<.in> extension will be processed as well, but not
linked from I<httpd.conf>.
=back
As mentioned before the converted files are created, any special token
in them are getting replaced with the appropriate values. For example
the token C<@ServerRoot@> will be replaced with the value defined by
the C<ServerRoot> directive, so you can write a file that does the
following:
file:my-extra.conf.in
---------------------
PerlSwitches [EMAIL PROTECTED]@/../lib
and assuming that the I<ServerRoot> is I<~/modperl-2.0/t/>, when
I<my-extra.conf> will be created, it'll look like:
file:my-extra.conf
------------------
PerlSwitches -I~/modperl-2.0/t/../lib
The valid tokens are defined in C<%Apache::TestConfig::Usage> and also
can be seen in the output of C<t/TEST -help>'s I<configuration
options> section. The tokens are case insensitive.
=head2 Special Configuration Files
Some of the files in the I<t/conf> directory have a special meaning,
since the C<Apache::Test> framework uses them for the minimal
configuration setup. But they can be overriden:
=over
=item *
if the file I<t/conf/httpd.conf.in> exists, it will be used instead of
the default template (in I<Apache/TestConfig.pm>).
=item *
if the file I<t/conf/extra.conf.in> exists, it will be used to
generate I<t/conf/extra.conf> with C<@variable@> substitutions.
=item *
if the file I<t/conf/extra.conf> exists, it will be included by
I<httpd.conf>.
=item *
if the file I<t/conf/modperl_extra.pl> exists, it will be included by
I<httpd.conf> as a mod_perl file (PerlRequire).
=back
=head1 Apache::Test Framework's Architecture
In the previous section we have written a basic test, which doesn't do
much. In the following sections we will explain how to write more
elaborate tests.
When you write the test for Apache, unless you want to test some
static resource, like fetching a file, usually you have to write a
response handler and the corresponding test that will generate a
request which will exercise this response handler and verify that the
response is as expected. From now we may call these two parts as
client and server parts of the test, or request and response parts of
the test.
In some cases the response part of the test runs the test inside
itself, so all it requires from the request part of the test, is to
generate the request and print out a complete response without doing
anything else. In such cases C<Apache::Test> can auto-generate the
client part of the test for you.
=head2 Developing Response-only Part of a Test
If you write only a response part of the test, C<Apache::Test> will
automatically generate the corresponding test part that will generated
the response. In this case your test should print I<'ok 1'>, I<'not ok
2'> responses as usual tests do. The autogenerated request part will
receive the response and print them out automatically completing the
C<Test::Harness> expectations.
The corresponding request part of the test is named just like the
response part, using the following translation:
$response_test =~ s|t/[^/]+/Test([^/]+)/(.*).pm$|t/\L$1\E/$2.t|;
so for example I<t/response/TestApache/write.pm> becomes:
I<t/apache/write.t>.
If we look at the autogenerated test I<t/apache/write.t>, we can see
that it starts with the warning that it has been autogenerated, so you
won't attempt to change it. Then you can see the trace of the calls
that generated this test, in case you want to figure out how the test
was generated. And finally the test loads the C<Apache::TestRequest>
module, imports the C<GET_BODY> shortcut and prints the response of
the generated request using the C<GET_BODY>:
use Apache::TestRequest 'GET_BODY';
print GET_BODY "/TestApache::write";
As you can see the request URI is autogenerated from the response test
name:
$response_test =~ s|.*/([^/]+)/(.*).pm$|/$1::$2|;
So I<t/response/TestApache/write.pm> becomes: I</TestApache::write>.
Now a simple response test may look like this:
package TestApache::write;
use strict;
use warnings FATAL => 'all';
use constant BUFSIZ => 512; #small for testing
use Apache::Const -compile => 'OK';
sub handler {
my $r = shift;
$r->content_type('text/plain');
$r->write("1..2\n");
$r->write("ok 1")
$r->write("not ok 2")
Apache::OK;
}
1;
[F] C<Apache::Const> is mod_perl 2.0's package, if you test under 1.0,
use the C<Apache::Constants> module instead [/F].
The configuration part for this test will be autogenerated by the
C<Apache::Test> framework and added to the autogenerated file
I<t/conf/httpd.conf>. In our case the following configuration section
will be added.
<Location /TestApache::write>
SetHandler modperl
PerlResponseHandler TestApache::write
</Location>
You should remember to run:
% t/TEST -clean
so when you run your new tests the new configuration will be added.
=head2 Developing Response and Request Parts of a Test
But in most cases you want to write a two parts test where the client
(request) parts generates various requests and tests the responses.
It's possible that the client part tests a static file or some other
feature that doesn't require a dynamic response. In this case, only
the request part of the test should be written.
If you need to write the complete test, with two parts, you proceed
just like in the previous section, but now you write the client part
of the test by yourself. It's quite easy, all you have to do is to
generate requests and check the response. So a typical test will look
like this:
file:t/apache/cool.t
--------------------
use strict;
use warnings FATAL => 'all';
use Apache::Test;
use Apache::TestUtil;
use Apache::TestRequest 'GET_BODY';
plan tests => 1; # plan one test.
Apache::TestRequest::module('default');
my $config = Apache::Test::config();
my $hostport = Apache::TestRequest::hostport($config) || '';
t_debug("connecting to $hostport");
my $received = GET_BODY "/TestApache::cool";
my $expected = "COOL";
ok t_cmp(
$expected,
$received,
"testing TestApache::cool",
);
See the C<Apache::TestUtil> manpage for more info on the t_cmp()
function (e.g. it works with regexs as well).
And the corresponding response part:
file:t/response/TestApache/cool.pm
----------------------------------
package TestApache::cool;
use strict;
use warnings FATAL => 'all';
use Apache::Const -compile => 'OK';
sub handler {
my $r = shift;
$r->content_type('text/plain');
$r->write("COOL");
Apache::OK;
}
1;
Again, remember to run I<t/TEST -clean> before running the new test so
the configuration will be created for it.
As you can see the test generates a request to I</TestApache::cool>,
and expects it to return I<"COOL">. If we run the test:
% ./t/TEST t/apache/cool
We see:
apache/cool....ok
All tests successful.
Files=1, Tests=1, 1 wallclock secs ( 0.52 cusr + 0.02 csys = 0.54 CPU)
But if we run it in the debug (verbose) mode, we can actually see what
we are testing, what was expected and what was received:
apache/cool....1..1
# connecting to localhost:8529
# testing : testing TestApache::cool
# expected: COOL
# received: COOL
ok 1
ok
All tests successful.
Files=1, Tests=1, 1 wallclock secs ( 0.49 cusr + 0.03 csys = 0.52 CPU)
So in case in our simple test we have received something different
from I<COOL> or nothing at all, we can immediately see what's the
problem.
The name of the request part of the test is very important. If
C<Apache::Test> cannot find the corresponding test for the response
part it'll automatically generate one and in this case it's probably
not what you want. Therefore when you choose the filename for the
test, make sure to pick the same C<Apache::Test> will pick. So if the
response part is named: I<t/response/TestApache/cool.pm> the request
part should be named I<t/apache/cool.t>. See the regular expression
that does that in the previous section.
=head2 Developing Test Response Handlers in C
If you need to exercise some C API and you don't have a Perl glue for
it, you can still use C<Apache::Test> for the testing. It allows you
to write response handlers in C and makes it easy to integrate these
with other Perl tests and use Perl for request part which will
exercise the C module.
The C modules look just like standard Apache C modules, with a couple
of differences to:
=over
=item a
help them fit into the test suite
=item b
allow them to compile nicely with Apache 1.x or 2.x.
=back
The I<httpd-test> ASF project is a good example to look at. The C
modules are located under: I<httpd-test/perl-framework/c-modules/>.
Look at I<c-modules/echo_post/echo_post.c> for a nice simple example.
C<mod_echo_post> simply echos data that is C<POST>ed to it.
The differences between vairous tests may be summarized as follows:
=over
=item *
If the first line is:
#define HTTPD_TEST_REQUIRE_APACHE 1
or
#define HTTPD_TEST_REQUIRE_APACHE 2
then the test will be skipped unless the version matches. If a module
is compatible with the version of Apache used then it will be
automatically compiled by I<t/TEST> with C<-DAPACHE1> or C<-DAPACHE2>
so you can conditionally compile it to suit different httpd versions.
=item *
If there is a section bounded by:
#if CONFIG_FOR_HTTPD_TEST
...
#endif
in the I<.c> file then that section will be inserted verbatim into
I<t/conf/httpd.conf> by I<t/TEST>.
=back
There is a certain amount of magic which hopefully allows most modules
to be compiled for Apache 1.3 or Apache 2.0 without any conditional
stuff. Replace XXX with the module name, for example echo_post or
random_chunk:
=over
=item *
You should:
#include "apache_httpd_test.h"
which should be preceded by an:
#define APACHE_HTTPD_TEST_HANDLER XXX_handler
I<apache_httpd_test.h> pulls in a lot of required includes and defines
some constants and types that are not defined for Apache 1.3.
=item *
The handler function should be:
static int XXX_handler(request_rec *r);
=item *
At the end of the file should be an:
APACHE_HTTPD_TEST_MODULE(XXX)
where XXX is the same as that in C<APACHE_HTTPD_TEST_HANDLER>. This
will generate the hooks and stuff.
=back
=head2 Request and Response Methods
If you have LWP (libwww-perl) installed its C<LWP::UserAgent> serves
as an user agent in tests, otherwise C<Apache::TestClient> tries to
emulate partial LWP functionality. So most of the LWP documentation
applies here, but the C<Apache::Test> framework provides shortcuts
that hide many details, making the test writing a simple and swift
task. Before using these shortcuts C<Apache::TestRequest> should be
loaded, and its import() method will fetch the shortcuts into the
caller namespace:
use Apache::TestRequest;
Request generation methods issue a request and return a response
object (C<HTTP::Response> if LWP is available). They are documented in
the C<HTTP::Request::Common> manpage. The following methods are
available:
=over
=item * GET
Issues the C<GET> request. For example, issue a request and retrieve
the response content:
$url = "$location?foo=1&bar=2";
$res = GET $url;
$str = $res->content;
To set request headers, supply them after the C<$url>, e.g.:
$res = GET $url, 'Content-type' => 'text/html';
=item * HEAD
Issues the C<HEAD> request. For example issue a request and check that
the response's I<Content-type> is I<text/plain>:
$url = "$location?foo=1&bar=2";
$res = HEAD $url;
ok $res->content_type() eq 'text/plain';
=item * POST
Issues the C<POST> request. For example:
$content = 'PARAM=%33';
$res = POST $location, content => $content;
The second argument to C<POST> can be a reference to an array or a
hash with key/value pairs to emulate HTML E<lt>formE<gt> C<POST>ing.
=item * PUT
Issues the C<PUT> request.
=item * OPTIONS
META: ???
=back
These are two special methods added by the C<Apache::Test> framework:
=over
=item * UPLOAD
This special method allows to upload a file or a string which will
look as an uploaded file to the server. To upload a file use:
UPLOAD $location, filename => $filename;
You can add extra request headers as well:
UPLOAD $location, filename => $filename, 'X-Header-Test' => 'Test';
To upload a string as a file, use:
UPLOAD $location, content => 'some data';
=item * UPLOAD_BODY
Retrieves the content from the response resulted from doing
C<UPLOAD>. It's equal to:
my $body = UPLOAD(@_)->content;
For example, this code retrieves the content of the response resulted
from file upload request:
my $str = UPLOAD_BODY $location, filename => $filename;
=back
Once the response object is returned, various response object methods
can be applied to it. Probably the most useful ones are:
$content = $res->content;
to retrieve the content fo the respose and:
$content_type = $res->header('Content-type');
to retrieve specific headers.
Refer to the C<HTTP::Response> manpage for a complete reference of
these and other methods.
A few response retrieval shortcuts can be used to retrieve the wanted
parts of the response. To apply these simply add the shortcut name to
one of the request shortcuts listed earlier. For example instead of
retrieving the content part of the response via:
$res = GET $url;
$str = $res->content;
simply use:
$str = GET_BODY $url;
=over
=item * RC
returns the I<response code>, equivalent to:
$res->code;
For example to test whether some URL is bogus:
use Apache::Const 'NOT_FOUND';
ok GET_RC('/bogus_url') == NOT_FOUND;
You usually need to import and use C<Apache::Const> constants for the
response code comparisons, rather then using codes' corresponding
numerical values directly. You can import groups of code as well. For
example:
use Apache::Const ':common';
Refer to the C<Apache::Const> manpage for a complete reference. Also
you may need to use C<APR> and mod_perl constants, which reside in
C<APR::Const> and C<ModPerl::Const> modules respectively.
=item * OK
tests whether the response was successful, equivalent to:
$res->is_success;
For example:
ok GET_OK '/foo';
=item * STR
returns the response (both, headers and body) as a string and is
equivalent to:
$res->as_string;
Mostly useful for debugging, for example:
use Apache::TestUtil;
t_debug POST_STR '/test.pl';
=item * HEAD
returns the headers part of the response as a multi-line string.
For example, this code dumps all the response headers:
use Apache::TestUtil;
t_debug GET_HEAD '/index.html';
=item * BODY
returns the response body and is equivalent to:
$res->content;
For example, this code validates that the response's body is the one
that was expected:
use Apache::TestUtil;
ok GET_BODY('/index.html') eq $expect;
=back
=head2 Other Request Generation helpers
META: these methods need documentation
Request part:
Apache::TestRequest::scheme('http'); #force http for t/TEST -ssl
Apache::TestRequest::module($module);
my $config = Apache::Test::config();
my $hostport = Apache::TestRequest::hostport($config);
Getting the request object?
Apache::TestRequest::user_agent()
=head2 Starting Multiple Servers
By default the C<Apache::Test> framework sets up only a single server
to test against.
In some cases you need to have more than one server. If this is the
situation, you have to override the I<maxclients> configuration
directive, whose default is 1. Usually this is done in C<t/TEST.PL> by
subclassing the parent test run class and overriding the
new_test_config() method. For example if the parent class is
C<Apache::TestRunPerl>, you can change your C<t/TEST.PL> to be:
use strict;
use warnings FATAL => 'all';
use lib "../lib"; # test against the source lib for easier dev
use lib map {("../blib/$_", "../../blib/$_")} qw(lib arch);
use Apache::TestRunPerl ();
package MyTest;
our @ISA = qw(Apache::TestRunPerl);
# subclass new_test_config to add some config vars which will be
# replaced in generated httpd.conf
sub new_test_config {
my $self = shift;
$self->{conf_opts}->{maxclients} = 2;
return $self->SUPER::new_test_config;
}
MyTest->new->run(@ARGV);
=head2 Multiple User Agents
By default the C<Apache::Test> framework uses a single user agent
which talks to the server (this is the C<LWP> user agent, if you have
C<LWP> installed). You almost never use this agent directly in the
tests, but via various wrappers. However if you need a second user
agent you can clone these. For example:
my $ua2 = Apache::TestRequest::user_agent()->clone;
=head2 Hitting the Same Interpreter (Server Thread/Process Instance)
When a single instance of the server thread/process is running, all
the tests go through the same server. However if the C<Apache::Test>
framework was configured to to run a few instances, two subsequent
sub-tests may not hit the same server instance. In certain tests
(e.g. testing the closure effect or the C<BEGIN> blocks) it's
important to make sure that a sequence of sub-tests are run against
the same server instance. The C<Apache::Test> framework supports this
internally.
Here is an example from C<ModPerl::Registry> closure tests. Using the
counter closure problem under C<ModPerl::Registry>:
file:cgi-bin/closure.pl
-----------------------
#!perl -w
print "Content-type: text/plain\r\n\r\n";
# this is a closure (when compiled inside handler()):
my $counter = 0;
counter();
sub counter {
#warn "$$";
print ++$counter;
}
If this script get invoked twice in a row and we make sure that it
gets executed by the same server instance, the first time it'll return
1 and the second time 2. So here is the gist of the request part that
makes sure that its two subsequent requests hit the same server
instance:
file:closure.t
--------------
...
my $url = "/same_interp/cgi-bin/closure.pl";
my $same_interp = Apache::TestRequest::same_interp_tie($url);
# should be no closure effect, always returns 1
my $first = req($same_interp, $url);
my $second = req($same_interp, $url);
ok t_cmp(
1,
$first && $second && ($second - $first),
"the closure problem is there",
);
sub req {
my($same_interp, $url) = @_;
my $res = Apache::TestRequest::same_interp_do($same_interp,
\&GET, $url);
return $res ? $res->content : undef;
}
In this test we generate two requests to I<cgi-bin/closure.pl> and
expect the returned value to increment for each new request, because
of the closure problem generated by C<ModPerl::Registry>. Since we
don't know whether some other test has called this script already, we
simply check whether the substraction of the two subsequent requests'
outputs gives a value of 1.
The test starts by requesting the server to tie a single instance to
all requests made with a certain identifier. This is done using the
same_interp_tie() function which returns a unique server instance's
indentifier. From now on any requests made through same_interp_do()
and supplying this indentifier as the first argument will be served by
the same server instance. The second argument to same_interp_do() is
the method to use for generating the request and the third is the URL
to use. Extra arguments can be supplied if needed by the request
generation method (e.g. headers).
This technique works for testing purposes where we know that we have
just a few server instances. What happens internally is when
same_interp_tie() is called the server instance that served it returns
its unique UUID, so when we want to hit the same server instance in
subsequent requests we generate the same request until we learn that
we are being served by the server instance that we want. This magic is
done by using a fixup handler which returns C<OK> only if it sees that
its unique id matches. As you understand this technique would be very
inefficient in production with many server instances.
=head1 Writing Tests
All the communications between tests and C<Test::Harness> which
executes them is done via STDOUT. I.e. whatever tests want to report
they do by printing something to STDOUT. If a test wants to print some
debug comment it should do it starting on a separate line, and each
debug line should start with C<#>. The t_debug() function from the
C<Apache::TestUtil> package should be used for that purpose.
=head2 Defining How Many Sub-Tests Are to Be Run
Before sub-tests of a certain test can be run it has to declare how
many sub-tests it is going to run. In some cases the test may decide
to skip some of its sub-tests or not to run any at all. Therefore the
first thing the test has to print is:
1..M\n
where M is a positive integer. So if the test plans to run 5 sub-tests
it should do:
print "1..5\n";
In C<Apache::Test> this is done as follows:
use Apache::Test;
plan tests => 5;
=head2 Skipping a Whole Test
Sometimes when the test cannot be run, because certain prerequisites
are missing. To tell C<Test::Harness> that the whole test is to be
skipped do:
print "1..0 # skipped because of foo is missing\n";
The optional comment after C<# skipped> will be used as a reason for
test's skipping. Under C<Apache::Test> the optional last argument to
the plan() function can be used to define prerequisites and skip the
test:
use Apache::Test;
plan tests => 5, $test_skipping_prerequisites;
This last argument can be:
=over
=item * a C<SCALAR>
the test is skipped if the scalar has a false value. For example:
plan tests => 5, 0;
=item * an C<ARRAY> reference
have_module() is called for each value in this array. The test is
skipped if have_module() returns false (which happens when at least
one C or Perl module from the list cannot be found). For example:
plan tests => 5, [qw(mod_index mod_mime)];
=item * a C<CODE> reference
the tests will be skipped if the function returns a false value. For
example:
plan tests => 5, \&have_lwp;
the test will be skipped if LWP is not available
=back
There is a number of useful functions whose return value can be used
as a last argument for plan():
=over
=item * have_module()
have_module() tests for presense of Perl modules or C modules
I<mod_*>. It accepts a list of modules or a reference to the list. If
at least one of the modules is not found it returns a false value,
otherwise it returns a true value. For example:
plan tests => 5, have_module qw(Chatbot::Eliza CGI mod_proxy);
will skip the whole test unless both Perl modules C<Chatbot::Eliza>
and C<CGI> and the C module I<mod_proxy.c> are available.
=item * have
have() called as a last argument of plan() can impose multiple
requirements at once.
have()'s arguments can include scalars, which are passed to
have_module(), and hash references. The hash references have a
condition code reference as a value and a reason for failure as a
key. The condition code is run and if it fails the provided reason is
used to tell user why the test was skipped.
For example:
plan tests => 5,
have 'LWP',
{ "perl >= 5.7.3 is required" => sub { $] >= 5.007003 } },
{ "not Win32" => sub { $^O eq 'MSWin32' } },
'cgid';
In this example, we require the presense of the C<LWP> Perl module,
C<mod_cgid>, that we run under perl E<gt>= 5.7.3 on Win32. If any of
the requirements from this list fail, the test will be skipped and
each failed requiremnt will print a reason for its failure.
=item * have_perl()
have_perl('foo') checks whether the value of C<$Config{foo}> or
C<$Config{usefoo}> is equal to I<'define'>. For example:
plan tests => 2, have_perl 'ithreads';
if Perl wasn't compiled with C<-Duseithreads> the condition will be
false and the test will be skipped.
Also it checks for Perl extensions. For example:
plan tests => 5, have_perl 'iolayers';
tests whether C<PerlIO> is available.
=item * have_lwp()
Tests whether the Perl module LWP is installed.
=item * have_http11()
Tries to tell LWP that sub-tests need to be run under HTTP 1.1
protocol. Fails if the installed version of LWP is not capable of
doing that.
=item * have_cgi()
tests whether mod_cgi or mod_cgid is available.
=item * have_apache()
tests for a specific version of httpd. For example:
plan tests => 2, have_apache 2;
will skip the test if not run under httpd-2.x.
plan tests => 2, have_apache 1;
will run the test only if run under Apache version 1.x.
=back
=head2 Skipping Numerous Tests
Just like you can tell C<Apache::Test> to run only specific tests, you
can tell it to run all but a few tests.
If all files in a directory I<t/foo> should be skipped, create:
file:t/foo/all.t
----------------
print "1..0\n";
Alternatively you can specify which tests should be skipped from a
single file I<t/SKIP>. This file includes a list of tests to be
skipped. You can include comments starting with C<#> and you can use
the C<*> wildcharacter for multiply files matching.
For example if in mod_perl 2.0 test suite we create the following file:
file:t/SKIP
-----------
# skip all files in protocol
protocol
# skip basic cgi test
modules/cgi.t
# skip all filter/input_* files
filter/input*.t
In our example the first pattern specifies the directory name
I<protocol>, since we want to skip all tests in it. But since the
skipping is done based on matching the skip patterns from t/SKIP
against a list of potential tests to be run, some other tests may be
skipped as well if they match the pattern. Therefore it's safer to use
a pattern like this:
protocol/*.t
The second pattern skips a single test I<modules/cgi.t>. Note that you
shouldn't specify the leading I<t/>. The I<.t> extension is optional,
so you can tell:
# skip basic cgi test
modules/cgi
The last pattern tells C<Apache::Test> to skip all the tests starting
with I<filter/input>.
=head2 Reporting a Success or a Failure of Sub-tests
After printing the number of planned sub-tests, and assuming that the
test is not skipped, the tests is running its sub-tests and each
sub-test is expected to report its success or failure by printing
I<ok> or I<not ok> respectively followed by its sequential number and
a new line. For example:
print "ok 1\n";
print "not ok 2\n";
print "ok 3\n";
In C<Apache::Test> this is done using the ok() function which prints
I<ok> if its argument is a true value, otherwise it prints I<not
ok>. In addition it keeps track of how many times it was called, and
every time it prints an incremental number, therefore you can move
sub-tests around without needing to remember to adjust sub-test's
sequential number, since now you don't need them at all. For example
this test snippet:
use Apache::Test;
use Apache::TestUtil;
plan tests => 3;
ok "success";
t_debug("expecting to fail next test");
ok "";
ok 0;
will print:
1..3
ok 1
# expecting to fail next test
not ok 2
not ok 3
Most of the sub-tests perform one of the following things:
=over
=item *
test whether some variable is defined:
ok defined $object;
=item *
test whether some variable is a true value:
ok $value;
or a false value:
ok !$value;
=item *
test whether a received from somewhere value is equal to an expected
value:
$expected = "a good value";
$received = get_value();
ok defined $received && $received eq $expected;
=back
=head2 Skipping Sub-tests
If the standard output line contains the substring I< # Skip> (with
variations in spacing and case) after I<ok> or I<ok NUMBER>, it is
counted as a skipped test. C<Test::Harness> reports the text after I<
# Skip\S*\s+> as a reason for skipping. So you can count a sub-test as
a skipped as follows:
print "ok 3 # Skip for some reason\n";
or using the C<Apache::Test>'s skip() function which works similarly
to ok():
skip $should_skip, $test_me;
so if C<$should_skip> is true, the test will be reported as
skipped. The second argument is the one that's sent to ok(), so if
C<$should_skip> is true, a normal ok() sub-test is run. The following
example represent four possible outcomes of using the skip() function:
skip_subtest_1.t
--------------
use Apache::Test;
plan tests => 4;
my $ok = 1;
my $not_ok = 0;
my $should_skip = "foo is missing";
skip $should_skip, $ok;
skip $should_skip, $not_ok;
$should_skip = '';
skip $should_skip, $ok;
skip $should_skip, $not_ok;
now we run the test:
% ./t/TEST -run-tests -verbose skip_subtest_1
skip_subtest_1....1..4
ok 1 # skip foo is missing
ok 2 # skip foo is missing
ok 3
not ok 4
# Failed test 4 in skip_subtest_1.t at line 13
Failed 1/1 test scripts, 0.00% okay. 1/4 subtests failed, 75.00% okay.
As you can see since C<$should_skip> had a true value, the first two
sub-tests were explicitly skipped (using C<$should_skip> as a reason),
so the second argument to skip didn't matter. In the last two
sub-tests C<$should_skip> had a false value therefore the second
argument was passed to the ok() function. Basically the following
code:
$should_skip = '';
skip $should_skip, $ok;
skip $should_skip, $not_ok;
is equivalent to:
ok $ok;
ok $not_ok;
C<Apache::Test> also allows to write tests in such a way that only
selected sub-tests will be run. The test simply needs to switch from
using ok() to sok(). Where the argument to sok() is a CODE reference
or a BLOCK whose return value will be passed to ok(). If sub-tests
are specified on the command line only those will be run/passed to
ok(), the rest will be skipped. If no sub-tests are specified, sok()
works just like ok(). For example, you can write this test:
file:skip_subtest_2.t
---------------------
use Apache::Test;
plan tests => 4;
sok {1};
sok {0};
sok sub {'true'};
sok sub {''};
and then ask to run only sub-tests 1 and 3 and to skip the rest.
% ./t/TEST -verbose skip_subtest_2 1 3
skip_subtest_2....1..4
ok 1
ok 2 # skip skipping this subtest
ok 3
ok 4 # skip skipping this subtest
ok, 2/4 skipped: skipping this subtest
All tests successful, 2 subtests skipped.
Only the sub-tests 1 and 3 get executed.
A range of sub-tests to run can be given using the Perl's range
operand:
% ./t/TEST -verbose skip_subtest_2 2..4
skip_subtest_2....1..4
ok 1 # skip askipping this subtest
not ok 2
# Failed test 2
ok 3
not ok 4
# Failed test 4
Failed 1/1 test scripts, 0.00% okay. 2/4 subtests failed, 50.00% okay.
In this run, only the first sub-test gets executed.
=head2 Todo Sub-tests
In a safe fashion to skipping specific sub-tests, it's possible to
declare some sub-tests as I<todo>. This distinction is useful when we
know that some sub-test is failing but for some reason we want to flag
it as a todo sub-test and not as a broken test. C<Test::Harness>
recognizes I<todo> sub-tests if the standard output line contains the
substring I< # TODO> after I<not ok> or I<not ok NUMBER> and is
counted as a todo sub-test. The text afterwards is the explanation of
the thing that has to be done before this sub-test will succeed. For
example:
print "not ok 42 # TODO not implemented\n";
In C<Apache::Test> this can be done with passing a reference to a list
of sub-tests numbers that should be marked as I<todo> sub-test:
plan tests => 7, todo => [3, 6];
In this example sub-tests 3 and 6 will be marked as I<todo> sub-tests.
=head2 Making it Easy to Debug
Ideally we want all the tests to pass, reporting minimum noise or none
at all. But when some sub-tests fail we want to know the reason for
their failure. If you are a developer you can dive into the code and
easily find out what's the problem, but when you have a user who has a
problem with the test suite it'll make his and your life much easier
if you make it easy for the user to report you the exact problem.
Usually this is done by printing the comment of what the sub-test
does, what is the expected value and what's the received value. This
is a good example of debug friendly sub-test:
file:debug_comments.t
---------------------
use Apache::Test;
use Apache::TestUtil;
plan tests => 1;
t_debug("testing feature foo");
$expected = "a good value";
$received = "a bad value";
t_debug("expected: $expected");
t_debug("received: $received");
ok defined $received && $received eq $expected;
If in this example C<$received> gets assigned I<a bad value> string,
the test will print the following:
% t/TEST debug_comments
debug_comments....FAILED test 1
No debug help here, since in a non-verbose mode the debug comments
aren't printed. If we run the same test using the verbose mode,
enabled with C<-verbose>:
% t/TEST -verbose debug_comments
debug_comments....1..1
# testing feature foo
# expected: a good value
# received: a bad value
not ok 1
we can see exactly what's the problem, by visual expecting of the
expected and received values.
It's true that adding a few print statements for each sub tests is
cumbersome, and adds a lot of noise, when you could just tell:
ok "a good value" eq "a bad value";
but no fear, C<Apache::TestUtil> comes to help. The function t_cmp()
does all the work for you:
use Apache::Test;
use Apache::TestUtil;
ok t_cmp(
"a good value",
"a bad value",
"testing feature foo");
t_cmp() will handle C<undef>'ined values as well, so you can do:
my $expected;
ok t_cmp(undef, $expected, "should be undef");
Finally you can use t_cmp() for regex comparisons. This feature is
mostly useful when there may be more than one valid expected value,
which can be described with regex. For example this can be useful to
inspect the value of C<$@> when eval() is expected to fail:
eval {foo();}
if ($@) {
ok t_cmp(qr/^expecting foo/, $@, "func eval");
}
which is the same as:
eval {foo();}
if ($@) {
t_debug("func eval");
ok $@ =~ /^expecting foo/ ? 1 : 0;
}
=head2 Tie-ing STDOUT to a Response Handler Object
It's possible to run the sub-tests in the response handler, and simply
return them as a response to the client which in turn will print them
out. Unfortunately in this case you cannot use ok() and other
functions, since they print and don't return the results, therefore
you have to do it manually. For example:
sub handler {
my $r = shift;
$r->print("1..2\n");
$r->print("ok 1\n");
$r->print("not ok 2\n");
return Apache::OK;
}
now the client should print the response to STDOUT for
C<Test::Harness> processing.
If the response handler is configured as:
SetHandler perl-script
C<STDOUT> is already tied to the request object C<$r>. Therefore you
can now rewrite the handler as:
use Apache::Test;
sub handler {
my $r = shift;
Apache::Test::test_pm_refresh();
plan tests => 2;
ok "true";
ok "";
return Apache::OK;
}
However to be on the safe side you also have to call
Apache::Test::test_pm_refresh() allowing plan() and friends to be
called more than once per-process.
Under different settings C<STDOUT> is not tied to the request object.
If the first argument to plan() is an object, such as an
C<Apache::RequestRec> object, C<STDOUT> will be tied to it. The
C<Test.pm> global state will also be refreshed by calling
C<Apache::Test::test_pm_refresh>. For example:
use Apache::Test;
sub handler {
my $r = shift;
plan $r, tests => 2;
ok "true";
ok "";
return Apache::OK;
}
Yet another alternative to handling the test framework printing inside
response handler is to use C<Apache::TestToString> class.
The C<Apache::TestToString> class is used to capture C<Test.pm> output
into a string. Example:
use Apache::Test;
sub handler {
my $r = shift;
Apache::TestToString->start;
plan tests => 2;
ok "true";
ok "";
my $output = Apache::TestToString->finish;
$r->print($output);
return Apache::OK;
}
In this example C<Apache::TestToString> intercepts and buffers all the
output from C<Test.pm> and can be retrieved with its finish()
method. Which then can be printed to the client in one
shot. Internally it calls Apache::Test::test_pm_refresh() to make sure
plan(), ok() and other functions() will work correctly more than one
test is running under the same interpreter.
=head2 Auto Configuration
If the test is comprised only from the request part, you have to
manually configure the targets you are going to use. This is usually
done in I<t/conf/extra.conf.in>.
If your tests are comprised from the request and response parts,
C<Apache::Test> automatically adds the configuration section for each
response handler it finds. For example for the response handler:
package TestResponse::nice;
... some code
1;
it will put into I<t/conf/httpd.conf>:
<Location /TestResponse::nice>
SetHandler modperl
PerlResponseHandler TestResponse::nice
</Location>
If you want to add some extra configuration directives, use the
C<__DATA__> section, as in this example:
package TestResponse::nice;
... some code
1;
__DATA__
PerlSetVar Foo Bar
These directives will be wrapped into the C<E<lt>LocationE<gt>>
section and placed into I<t/conf/httpd.conf>:
<Location /TestResponse::nice>
SetHandler modperl
PerlResponseHandler TestResponse::nice
PerlSetVar Foo Bar
</Location>
This autoconfiguration feature was added to:
=over
=item *
simplify (less lines) test configuration.
=item *
ensure unique namespace for E<lt>Location ...E<gt>'s.
=item *
force E<lt>Location ...E<gt> names to be consistent.
=item *
prevent clashes within main configuration.
=back
If some directives are supposed to go to the base configuration,
i.e. not to be automatically wrapped into C<E<lt>LocationE<gt>> block,
you should use a special C<E<lt>BaseE<gt>>..C<E<lt>/BaseE<gt>> block:
__DATA__
<Base>
PerlSetVar Config ServerConfig
<Base>
PerlSetVar Config LocalConfig
Now the autogenerated section will look like this:
PerlSetVar Config ServerConfig
<Location /TestResponse::nice>
SetHandler modperl
PerlResponseHandler TestResponse::nice
PerlSetVar Config LocalConfig
</Location>
As you can see the C<E<lt>BaseE<gt>>..C<E<lt>/BaseE<gt>> block has
gone. As you can imagine this block was added to support our virtue of
laziness, since most tests don't need to add directives to the base
configuration and we want to keep the configuration sections in tests
to a minimum and let Perl do the rest of the job for us.
META: Virtual host?
META: a special -configure time method in response part:
APACHE_TEST_CONFIGURE
=head2 Threaded versus Non-threaded Perl Test's Compatibility
Since the tests are supposed to run properly under non-threaded and
threaded perl, you have to worry to enclose the threaded perl specific
configuration bits in:
<IfDefine PERL_USEITHREADS>
... configuration bits
</IfDefine>
C<Apache::Test> will start the server with -DPERL_USEITHREADS if the
Perl is ithreaded.
For example C<PerlOptions +Parent> is valid only for the threaded
perl, therefore you have to write:
<IfDefine PERL_USEITHREADS>
# a new interpreter pool
PerlOptions +Parent
</IfDefine>
Just like the configuration, the test's code has to work for both
versions as well. Therefore you should wrap the code specific to the
threaded perl into:
if (have_perl 'ithreads'){
# ithread specific code
}
which is essentially does a lookup in $Config{useithreads}.
=head2 Retrieving the Server Configuration Data
The server configuration data can be retrieved and used in the tests
via the configuration object:
use Apache::Test;
my $cfg = Apache::Test::config();
=head3 Module Magic Number
The following code retrieves the major and minor MMN numbers.
my $cfg = Apache::Test::config();
my $info = $cfg->{httpd_info};
my $major = $info->{MODULE_MAGIC_NUMBER_MAJOR};
my $minor = $info->{MODULE_MAGIC_NUMBER_MINOR};
print "major=$major, minor=$minor\n";
For example for MMN C<20011218:0>, this code prints:
major=20011218, minor=0
=head1 Debugging Tests
Sometimes your tests won't run properly or even worse will
segfault. There are cases where it's possible to debug broken tests
with simple print statements but usually it's very time consuming and
ineffective. Therefore it's a good idea to get yourself familiar with
Perl and C debuggers, and this knowledge will save you a lot of time
and grief in a long run.
=head2 Under C debugger
mod_perl-2.0 provides built in 'make test' debug facility. So in case
you get a core dump during make test, or just for fun, run in one shell:
% t/TEST -debug
in another shell:
% t/TEST -run-tests
then the I<-debug> shell will have a C<(gdb)> prompt, type C<where>
for stacktrace:
(gdb) where
You can change the default debugger by supplying the name of the
debugger as an argument to I<-debug>. E.g. to run the server under
C<ddd>:
% ./t/TEST -debug=ddd
META: list supported debuggers
If you debug mod_perl internals you can set the breakpoints using the
I<-breakpoint> option, which can be repeated as many times as
needed. When you set at least one breakpoint, the server will start
running till it meets the I<ap_run_pre_config> breakpoint. At this
point we can set the breakpoint for the mod_perl code, something we
cannot do earlier if mod_perl was built as DSO. For example:
% ./t/TEST -debug -breakpoint=modperl_cmd_switches \
-breakpoint=modperl_cmd_options
will set the I<modperl_cmd_switches> and I<modperl_cmd_options>
breakpoints and run the debugger.
If you want to tell the debugger to jump to the start of the mod_perl
code you may run:
% ./t/TEST -debug -breakpoint=modperl_hook_init
In fact I<-breakpoint> automatically turns on the debug mode, so you
can run:
% ./t/TEST -breakpoint=modperl_hook_init
=head2 Under Perl debugger
When the Perl code misbehaves it's the best to run it under the Perl
debugger. Normally started as:
% perl -debug program.pl
the flow control gets passed to the Perl debugger, which allows you to
run the program in single steps and examine its states and variables
after every executed statement. Of course you can set up breakpoints
and watches to skip irrelevant code sections and watch after certain
variables. The I<perldebug> and the I<perldebtut> manpages are
covering the Perl debugger in fine details.
The C<Apache::Test> framework extends the Perl debugger and plugs in
C<LWP>'s debug features, so you can debug the requests. Let's take
test I<apache/read> from mod_perl 2.0 and present the features as we
go:
META: to be completed
run .t test under the perl debugger
% t/TEST -debug perl t/modules/access.t
run .t test under the perl debugger (nonstop mode, output to
t/logs/perldb.out)
% t/TEST -debug perl=nostop t/modules/access.t
turn on -v and LWP trace (1 is the default) mode in Apache::TestRequest
% t/TEST -debug lwp t/modules/access.t
turn on -v and LWP trace mode (level 2) in Apache::TestRequest
% t/TEST -debug lwp=2 t/modules/access.t
=head2 Tracing
To get Start the server under strace(1):
% t/TEST -debug strace
The output goes to I<t/logs/strace.log>.
Now in a second terminal run:
% t/TEST -run-tests
Beware that I<t/logs/strace.log> is going to be very big.
META: can we provide strace(1) opts if we want to see only certain
syscalls?
=head1 Writing Tests Methodology
META: to be completed
=head2 When Tests Should Be Written
=over
=item * A New feature is Added
Every time a new feature is added new tests should be added to cover
the new feature.
=item * A Bug is Reported
Every time a bug gets reported, before you even attempt to fix the
bug, write a test that exposes the bug. This will make much easier for
you to test whether your fix actually fixes the bug.
Now fix the bug and make sure that test passes ok.
It's possible that a few tests can be written to expose the same
bug. Write them all -- the more tests you have the less chances are
that there is a bug in your code.
If the person reporting the bug is a programmer you may try to ask her
to write the test for you. But usually if the report includes a simple
code that reproduces the bug, it should probably be easy to convert
this code into a test.
=back
=head1 Other Webserver Regression Testing Frameworks
=over
=item * Puffin
Puffin is a web application regression testing system. It allows you
to test any web application from end to end based application as if it
were a "black box" accepting inputs and returning outputs.
It's available from http://puffin.sourceforge.net/
=back
=head1 References
=over
=item * extreme programming methodology
Extreme Programming: A Gentle Introduction:
http://www.extremeprogramming.org/.
Extreme Programming: http://www.xprogramming.com/.
See also other sites linked from these URLs.
=back
=head1 Maintainers
Maintainer is the person(s) you should contact with updates,
corrections and patches.
=over
=item *
Stas Bekman E<lt>stas (at) stason.orgE<gt>
=back
=head1 Authors
=over
=item *
Stas Bekman E<lt>stas (at) stason.orgE<gt>
=back
Only the major authors are listed above. For contributors see the
Changes file.
=cut
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