Provided by: libtest-class-perl_0.52-1_all 
NAME
Test::Class - Easily create test classes in an xUnit/JUnit style
VERSION
version 0.51
SYNOPSIS
package Example::Test;
use base qw(Test::Class);
use Test::More;
# setup methods are run before every test method.
sub make_fixture : Test(setup) {
my $array = [1, 2];
shift->{test_array} = $array;
}
# a test method that runs 1 test
sub test_push : Test {
my $array = shift->{test_array};
push @$array, 3;
is_deeply($array, [1, 2, 3], 'push worked');
}
# a test method that runs 4 tests
sub test_pop : Test(4) {
my $array = shift->{test_array};
is(pop @$array, 2, 'pop = 2');
is(pop @$array, 1, 'pop = 1');
is_deeply($array, [], 'array empty');
is(pop @$array, undef, 'pop = undef');
}
# teardown methods are run after every test method.
sub teardown : Test(teardown) {
my $array = shift->{test_array};
diag("array = (@$array) after test(s)");
}
later in a nearby .t file
#! /usr/bin/perl
use Example::Test;
# run all the test methods in Example::Test
Test::Class->runtests;
Outputs:
1..5
ok 1 - pop = 2
ok 2 - pop = 1
ok 3 - array empty
ok 4 - pop = undef
# array = () after test(s)
ok 5 - push worked
# array = (1 2 3) after test(s)
DESCRIPTION
Test::Class provides a simple way of creating classes and objects to test your code in an xUnit style.
Built using Test::Builder, it was designed to work with other Test::Builder based modules (Test::More,
Test::Differences, Test::Exception, etc.).
Note: This module will make more sense, if you are already familiar with the "standard" mechanisms for
testing perl code. Those unfamiliar with Test::Harness, Test::Simple, Test::More and friends should go
take a look at them now. Test::Tutorial is a good starting point.
INTRODUCTION
A brief history lesson
In 1994 Kent Beck wrote a testing framework for Smalltalk called SUnit. It was popular. You can read a
copy of his original paper at <http://www.xprogramming.com/testfram.htm>.
Later Kent Beck and Erich Gamma created JUnit for testing Java <http://www.junit.org/>. It was popular
too.
Now there are xUnit frameworks for every language from Ada to XSLT. You can find a list at
<http://www.xprogramming.com/software.htm>.
While xUnit frameworks are traditionally associated with unit testing they are also useful in the
creation of functional/acceptance tests.
Test::Class is (yet another) implementation of xUnit style testing in Perl.
Why you should use Test::Class
Test::Class attempts to provide simple xUnit testing that integrates simply with the standard perl *.t
style of testing. In particular:
• All the advantages of xUnit testing. You can easily create test fixtures and isolate tests. It
provides a framework that should be familiar to people who have used other xUnit style test systems.
• It is built with Test::Builder and should co-exist happily with all other Test::Builder based
modules. This makes using test classes in *.t scripts, and refactoring normal tests into test
classes, much simpler because:
• You do not have to learn a new set of new test APIs and can continue using ok(), like(), etc.
from Test::More and friends.
• Skipping tests and todo tests are supported.
• You can have normal tests and Test::Class classes co-existing in the same *.t script. You don't
have to re-write an entire script, but can use test classes as and when it proves useful.
• You can easily package your tests as classes/modules, rather than *.t scripts. This simplifies reuse,
documentation and distribution, encourages refactoring, and allows tests to be extended by
inheritance.
• You can have multiple setup/teardown methods. For example have one teardown method to clean up
resources and another to check that class invariants still hold.
• It can make running tests faster. Once you have refactored your *.t scripts into classes they can be
easily run from a single script. This gains you the (often considerable) start up time that each
separate *.t script takes.
Why you should not use Test::Class
• If your *.t scripts are working fine then don't bother with Test::Class. For simple test suites it is
almost certainly overkill. Don't start thinking about using Test::Class until issues like duplicate
code in your test scripts start to annoy.
• If you are distributing your code it is yet another module that the user has to have to run your
tests (unless you distribute it with your test suite of course).
• If you are used to the TestCase/Suite/Runner class structure used by JUnit and similar testing
frameworks you may find Test::Unit more familiar (but try reading "HELP FOR CONFUSED JUNIT USERS"
before you give up).
TEST CLASSES
A test class is just a class that inherits from Test::Class. Defining a test class is as simple as doing:
package Example::Test;
use base qw(Test::Class);
Since Test::Class does not provide its own test functions, but uses those provided by Test::More and
friends, you will nearly always also want to have:
use Test::More;
to import the test functions into your test class.
METHOD TYPES
There are three different types of method you can define using Test::Class.
1) Test methods
You define test methods using the Test attribute. For example:
package Example::Test;
use base qw(Test::Class);
use Test::More;
sub subtraction : Test {
is( 2-1, 1, 'subtraction works' );
}
This declares the "subtraction" method as a test method that runs one test.
If your test method runs more than one test, you should put the number of tests in brackets like this:
sub addition : Test(2) {
is(10 + 20, 30, 'addition works');
is(20 + 10, 30, ' both ways');
}
If you don't know the number of tests at compile time you can use "no_plan" like this.
sub check_class : Test(no_plan) {
my $objects = shift->{objects};
isa_ok($_, "Object") foreach @$objects;
}
or use the :Tests attribute, which acts just like ":Test" but defaults to "no_plan" if no number is
given:
sub check_class : Tests {
my $objects = shift->{objects};
isa_ok($_, "Object") foreach @$objects;
}
2) Setup and teardown methods
Setup and teardown methods are run before and after every test. For example:
sub before : Test(setup) { diag("running before test") }
sub after : Test(teardown) { diag("running after test") }
You can use setup and teardown methods to create common objects used by all of your test methods (a test
fixture) and store them in your Test::Class object, treating it as a hash. For example:
sub pig : Test(setup) {
my $self = shift;
$self->{test_pig} = Pig->new;
}
sub born_hungry : Test {
my $pig = shift->{test_pig};
is($pig->hungry, 'pigs are born hungry');
}
sub eats : Test(3) {
my $pig = shift->{test_pig};
ok( $pig->feed, 'pig fed okay');
ok(! $pig->hungry, 'fed pig not hungry');
ok(! $pig->feed, 'cannot feed full pig');
}
You can also declare setup and teardown methods as running tests. For example you could check that the
test pig survives each test method by doing:
sub pig_alive : Test(teardown => 1) {
my $pig = shift->{test_pig};
ok($pig->alive, 'pig survived tests' );
}
3) Startup and shutdown methods
Startup and shutdown methods are like setup and teardown methods for the whole test class. All the
startup methods are run once when you start running a test class. All the shutdown methods are run once
just before a test class stops running.
You can use these to create and destroy expensive objects that you don't want to have to create and
destroy for every test - a database connection for example:
sub db_connect : Test(startup) {
shift->{dbi} = DBI->connect;
}
sub db_disconnect : Test(shutdown) {
shift->{dbi}->disconnect;
}
Just like setup and teardown methods you can pass an optional number of tests to startup and shutdown
methods. For example:
sub example : Test(startup => 1) {
ok(1, 'a startup method with one test');
}
If you want to run an unknown number of tests within your startup method, you need to say e.g.
sub example : Test(startup => no_plan) {
ok(1, q{The first of many tests that don't want to have to count});
...
}
as the : Tests attribute behaves exactly like : Test in this context.
If a startup method has a failing test or throws an exception then all other tests for the current test
object are ignored.
RUNNING TESTS
You run test methods with runtests(). Doing:
Test::Class->runtests
runs all of the test methods in every loaded test class. This allows you to easily load multiple test
classes in a *.t file and run them all.
#! /usr/bin/perl
# load all the test classes I want to run
use Foo::Test;
use Foo::Bar::Test;
use Foo::Fribble::Test;
use Foo::Ni::Test;
# and run them all
Test::Class->runtests;
You can use Test::Class::Load to automatically load all the test classes in a given set of directories.
If you need finer control you can create individual test objects with new(). For example to just run the
tests in the test class "Foo::Bar::Test" you can do:
Example::Test->new->runtests
You can also pass runtests() a list of test objects to run. For example:
my $o1 = Example::Test->new;
my $o2 = Another::Test->new;
# runs all the tests in $o1 and $o2
$o1->runtests($o2);
Since, by definition, the base Test::Class has no tests, you could also have written:
my $o1 = Example::Test->new;
my $o2 = Another::Test->new;
Test::Class->runtests($o1, $o2);
If you pass runtests() class names it will automatically create test objects for you, so the above can be
written more compactly as:
Test::Class->runtests(qw( Example::Test Another::Test ))
In all of the above examples runtests() will look at the number of tests both test classes run and output
an appropriate test header for Test::Harness automatically.
What happens if you run test classes and normal tests in the same script? For example:
Test::Class->runtests;
ok(Example->new->foo, 'a test not in the test class');
ok(Example->new->bar, 'ditto');
Test::Harness will complain that it saw more tests than it expected since the test header output by
runtests() will not include the two normal tests.
To overcome this problem you can pass an integer value to runtests(). This is added to the total number
of tests in the test header. So the problematic example can be rewritten as follows:
Test::Class->runtests(+2);
ok(Example->new->foo, 'a test not in the test class');
ok(Example->new->bar, 'ditto');
If you prefer to write your test plan explicitly you can use expected_tests() to find out the number of
tests a class/object is expected to run.
Since runtests() will not output a test plan if one has already been set, the previous example can be
written as:
plan tests => Test::Class->expected_tests(+2);
Test::Class->runtests;
ok(Example->new->foo, 'a test not in the test class');
ok(Example->new->bar, 'ditto');
Remember: Test objects are just normal perl objects. Test classes are just normal perl classes. Setup,
test and teardown methods are just normal methods. You are completely free to have other methods in your
class that are called from your test methods, or have object specific "new" and "DESTROY" methods.
In particular you can override the new() method to pass parameters to your test object, or re-define the
number of tests a method will run. See num_method_tests() for an example.
TEST DESCRIPTIONS
The test functions you import from Test::More and other Test::Builder based modules usually take an
optional third argument that specifies the test description, for example:
is $something, $something_else, 'a description of my test';
If you do not supply a test description, and the test function does not supply its own default, then
Test::Class will use the name of the currently running test method, replacing all "_" characters with
spaces so:
sub one_plus_one_is_two : Test {
is 1+1, 2;
}
will result in:
ok 1 - one plus one is two
RUNNING ORDER OF METHODS
Methods of each type are run in the following order:
1. All of the startup methods in alphabetical order
2. For each test method, in alphabetical order:
• All of the setup methods in alphabetical order
• The test method.
• All of the teardown methods in alphabetical order
3. All of the shutdown methods in alphabetical order.
Most of the time you should not care what order tests are run in, but it can occasionally be useful to
force some test methods to be run early. For example:
sub _check_new {
my $self = shift;
isa_ok(Object->new, "Object") or $self->BAILOUT('new fails!');
}
The leading "_" will force the above method to run first - allowing the entire suite to be aborted before
any other test methods run.
HANDLING EXCEPTIONS
If a startup, setup, test, teardown or shutdown method dies then runtests() will catch the exception and
fail any remaining test. For example:
sub test_object : Test(2) {
my $object = Object->new;
isa_ok( $object, "Object" ) or die "could not create object\n";
ok( $object->open, "open worked" );
}
will produce the following if the first test failed:
not ok 1 - The object isa Object
# Failed test 'The object isa Object'
# at /Users/adrianh/Desktop/foo.pl line 14.
# (in MyTest->test_object)
# The object isn't defined
not ok 2 - test_object died (could not create object)
# Failed test 'test_object died (could not create object)'
# at /Users/adrianh/Desktop/foo.pl line 19.
# (in MyTest->test_object)
This can considerably simplify testing code that throws exceptions.
Rather than having to explicitly check that the code exited normally (e.g. with "lives_ok" in
Test::Exception) the test will fail automatically - without aborting the other test methods. For example
contrast:
use Test::Exception;
my $file;
lives_ok { $file = read_file('test.txt') } 'file read';
is($file, "content", 'test file read');
with:
sub read_file : Test {
is(read_file('test.txt'), "content", 'test file read');
}
If more than one test remains after an exception then the first one is failed, and the remaining ones are
skipped.
If the setup method of a test method dies, then all of the remaining setup and shutdown methods are also
skipped.
Since startup methods will usually be creating state needed by all the other test methods, an exception
within a startup method will prevent all other test methods of that class running.
RETURNING EARLY
If a test method returns before it has run all of its tests, by default the missing tests are deemed to
have been skipped; see "Skipped Tests" for more information.
However, if the class's "fail_if_returned_early" method returns true, then the missing tests will be
deemed to have failed. For example,
package MyClass;
use base 'Test::Class';
sub fail_if_returned_early { 1 }
sub oops : Tests(8) {
for (my $n=1; $n*$n<50; ++$n) {
ok 1, "$n squared is less than fifty";
}
}
RETURNING LATE
If a test method runs too many tests, by default the test plan succeeds.
However, if the class's "fail_if_returned_late" method returns true, then the extra tests will trigger a
failure. For example,
package MyClass;
use base 'Test::Class';
sub fail_if_returned_late { 1 }
sub oops : Tests(1) {
ok 1, "just a simple test";
ok 1, "just a simple test"; #oops I copied and pasted too many tests
}
SKIPPED TESTS
You can skip the rest of the tests in a method by returning from the method before all the test have
finished running (but see "Returning Early" for how to change this). The value returned is used as the
reason for the tests being skipped.
This makes managing tests that can be skipped for multiple reasons very simple. For example:
sub flying_pigs : Test(5) {
my $pig = Pig->new;
isa_ok($pig, 'Pig') or return("cannot breed pigs")
can_ok($pig, 'takeoff') or return("pigs don't fly here");
ok($pig->takeoff, 'takeoff') or return("takeoff failed");
ok( $pig->altitude > 0, 'Pig is airborne' );
ok( $pig->airspeed > 0, ' and moving' );
}
If you run this test in an environment where "Pig->new" worked and the takeoff method existed, but failed
when ran, you would get:
ok 1 - The object isa Pig
ok 2 - can takeoff
not ok 3 - takeoff
ok 4 # skip takeoff failed
ok 5 # skip takeoff failed
You can also skip tests just as you do in Test::More or Test::Builder - see "Conditional tests" in
Test::More for more information.
Note: if you want to skip tests in a method with "no_plan" tests then you have to explicitly skip the
tests in the method - since Test::Class cannot determine how many tests (if any) should be skipped:
sub test_objects : Tests {
my $self = shift;
my $objects = $self->{objects};
if (@$objects) {
isa_ok($_, "Object") foreach (@$objects);
} else {
$self->builder->skip("no objects to test");
}
}
Another way of overcoming this problem is to explicitly set the number of tests for the method at run
time using num_method_tests() or "num_tests".
You can make a test class skip all of its tests by setting SKIP_CLASS() before runtests() is called.
TO DO TESTS
You can create todo tests just as you do in Test::More and Test::Builder using the $TODO variable. For
example:
sub live_test : Test {
local $TODO = "live currently unimplemented";
ok(Object->live, "object live");
}
See "Todo tests" in Test::Harness for more information.
EXTENDING TEST CLASSES BY INHERITANCE
You can extend test methods by inheritance in the usual way. For example consider the following test
class for a "Pig" object.
package Pig::Test;
use base qw(Test::Class);
use Test::More;
sub testing_class { "Pig" }
sub new_args { (-age => 3) }
sub setup : Test(setup) {
my $self = shift;
my $class = $self->testing_class;
my @args = $self->new_args;
$self->{pig} = $class->new( @args );
}
sub _creation : Test {
my $self = shift;
isa_ok($self->{pig}, $self->testing_class)
or $self->FAIL_ALL('Pig->new failed');
}
sub check_fields : Test {
my $pig = shift->{pig}
is($pig->age, 3, "age accessed");
}
Next consider "NamedPig" a subclass of "Pig" where you can give your pig a name.
We want to make sure that all the tests for the "Pig" object still work for "NamedPig". We can do this by
subclassing "Pig::Test" and overriding the "testing_class" and "new_args" methods.
package NamedPig::Test;
use base qw(Pig::Test);
use Test::More;
sub testing_class { "NamedPig" }
sub new_args { (shift->SUPER::new_args, -name => 'Porky') }
Now we need to test the name method. We could write another test method, but we also have the option of
extending the existing "check_fields" method.
sub check_fields : Test(2) {
my $self = shift;
$self->SUPER::check_fields;
is($self->{pig}->name, 'Porky', 'name accessed');
}
While the above works, the total number of tests for the method is dependent on the number of tests in
its "SUPER::check_fields". If we add a test to "Pig::Test->check_fields" we will also have to update the
number of tests of "NamedPig::test->check_fields".
Test::Class allows us to state explicitly that we are adding tests to an existing method by using the "+"
prefix. Since we are adding a single test to "check_fields", it can be rewritten as:
sub check_fields : Test(+1) {
my $self = shift;
$self->SUPER::check_fields;
is($self->{pig}->name, 'Porky', 'name accessed');
}
With the above definition you can add tests to "check_fields" in "Pig::Test" without affecting
"NamedPig::Test".
RUNNING INDIVIDUAL TESTS
NOTE: The exact mechanism for running individual tests is likely to change in the future.
Sometimes you just want to run a single test. Commenting out other tests or writing code to skip them
can be a hassle, so you can specify the "TEST_METHOD" environment variable. The value is expected to be
a valid regular expression and, if present, only runs test methods whose names match the regular
expression. Startup, setup, teardown and shutdown tests will still be run.
One easy way of doing this is by specifying the environment variable before the "runtests" method is
called.
Running a test named "customer_profile":
#! /usr/bin/perl
use Example::Test;
$ENV{TEST_METHOD} = 'customer_profile';
Test::Class->runtests;
Running all tests with "customer" in their name:
#! /usr/bin/perl
use Example::Test;
$ENV{TEST_METHOD} = '.*customer.*';
Test::Class->runtests;
If you specify an invalid regular expression, your tests will not be run:
#! /usr/bin/perl
use Example::Test;
$ENV{TEST_METHOD} = 'C++';
Test::Class->runtests;
And when you run it:
TEST_METHOD (C++) is not a valid regular expression: Search pattern \
not terminated at (eval 17) line 1.
ORGANISING YOUR TEST CLASSES
You can, of course, organise your test modules as you wish. My personal preferences is:
• Name test classes with a suffix of "::Test" so the test class for the "Foo::Bar" module would be
"Foo::Bar::Test".
• Place all test classes in t/lib.
The Test::Class::Load provides a simple mechanism for easily loading all of the test classes in a given
set of directories.
A NOTE ON LOADING TEST CLASSES
Due to its use of subroutine attributes Test::Class based modules must be loaded at compile rather than
run time. This is because the :Test attribute is applied by a CHECK block.
This can be problematic if you want to dynamically load Test::Class modules. Basically while:
require $some_test_class;
will break, doing:
BEGIN { require $some_test_class }
will work just fine. For more information on CHECK blocks see "BEGIN, CHECK, INIT and END" in perlmod.
If you still can't arrange for your classes to be loaded at runtime, you could use an alternative
mechanism for adding your tests:
# sub test_something : Test(3) {...}
# becomes
sub test_something {...}
__PACKAGE__->add_testinfo('test_something', test => 3);
See the add_testinfo method for more details.
Additionally, if you've forgotten to enable warnings and have two test subs called the same thing, you
will get the same error.
GENERAL FILTERING OF TESTS
The use of $ENV{TEST_METHOD} to run just a subset of tests is useful, but sometimes it doesn't give the
level of granularity that you desire. Another feature of this class is the ability to do filtering on
other static criteria. In order to permit this, a generic filtering method is supported. This can be
used by specifying coderefs to the 'add_filter' method of this class.
In determining which tests should be run, all filters that have previously been specified via the
add_filter method will be run in-turn for each normal test method. If any of these filters return a
false value, the method will not be executed, or included in the number of tests. Note that filters will
only be run for normal test methods, they are ignored for startup, shutdown, setup, and teardown test
methods.
Note that test filters are global, and will affect all tests in all classes, not just the one that they
were defined in.
An example of this mechanism that mostly simulates the use of TEST_METHOD above is:
package MyTests;
use Test::More;
use base qw( Test::Class );
my $MYTEST_METHOD = qr/^t_not_filtered$/;
my $filter = sub {
my ( $test_class, $test_method ) = @_;
return $test_method =~ $MYTEST_METHOD;
}
Test::Class->add_filter( $filter );
sub t_filtered : Test( 1 ) {
fail( "filtered test run" );
}
sub t_not_filtered : Test( 1 ) {
pass( "unfiltered test run" );
}
METHODS
Creating and running tests
Test
# test methods
sub method_name : Test { ... }
sub method_name : Test(N) { ... }
# setup methods
sub method_name : Test(setup) { ... }
sub method_name : Test(setup => N) { ... }
# teardown methods
sub method_name : Test(teardown) { ... }
sub method_name : Test(teardown => N) { ... }
# startup methods
sub method_name : Test(startup) { ... }
sub method_name : Test(startup => N) { ... }
# shutdown methods
sub method_name : Test(shutdown) { ... }
sub method_name : Test(shutdown => N) { ... }
Marks a startup, setup, test, teardown or shutdown method. See runtests() for information on how to
run methods declared with the "Test" attribute.
N specifies the number of tests the method runs.
• If N is an integer then the method should run exactly N tests.
• If N is an integer with a "+" prefix then the method is expected to call its "SUPER::" method and
extend it by running N additional tests.
• If N is the string "no_plan" then the method can run an arbitrary number of tests.
If N is not specified it defaults to 1 for test methods, and 0 for startup, setup, teardown and
shutdown methods.
You can change the number of tests that a method runs using num_method_tests() or num_tests().
Tests
sub method_name : Tests { ... }
sub method_name : Tests(N) { ... }
Acts just like the ":Test" attribute, except that if the number of tests is not specified it defaults
to "no_plan". So the following are equivalent:
sub silly1 :Test( no_plan ) { ok(1) foreach (1 .. rand 5) }
sub silly2 :Tests { ok(1) foreach (1 .. rand 5) }
new
$Tests = CLASS->new(KEY => VAL ...)
$Tests2 = $Tests->new(KEY => VAL ...)
Creates a new test object (blessed hashref) containing the specified key/value pairs.
If called as an object method the existing object's key/value pairs are copied into the new object.
Any key/value pairs passed to "new" override those in the original object if duplicates occur.
Since the test object is passed to every test method as it runs, it is a convenient place to store
test fixtures. For example:
sub make_fixture : Test(setup) {
my $self = shift;
$self->{object} = Object->new();
$self->{dbh} = Mock::DBI->new(-type => normal);
}
sub test_open : Test {
my $self = shift;
my ($o, $dbh) = ($self->{object}, $self->{dbh});
ok($o->open($dbh), "opened ok");
}
See num_method_tests() for an example of overriding "new".
expected_tests
$n = $Tests->expected_tests
$n = CLASS->expected_tests
$n = $Tests->expected_tests(TEST, ...)
$n = CLASS->expected_tests(TEST, ...)
Returns the total number of tests that runtests() will run on the specified class/object. This
includes tests run by any setup and teardown methods.
Will return "no_plan" if the exact number of tests is undetermined (i.e. if any setup, test or
teardown method has an undetermined number of tests).
The "expected_tests" of an object after runtests() has been executed will include any run time
changes to the expected number of tests made by num_tests() or num_method_tests().
"expected_tests" can also take an optional list of test objects, test classes and integers. In this
case the result is the total number of expected tests for all the test/object classes (including the
one the method was applied to) plus any integer values.
"expected_tests" is useful when you're integrating one or more test classes into a more traditional
test script, for example:
use Test::More;
use My::Test::Class;
plan tests => My::Test::Class->expected_tests(+2);
ok(whatever, 'a test');
ok(whatever, 'another test');
My::Test::Class->runtests;
runtests
$allok = $Tests->runtests
$allok = CLASS->runtests
$allok = $Tests->runtests(TEST, ...)
$allok = CLASS->runtests(TEST, ...)
"runtests" is used to run test classes. At its most basic doing:
$test->runtests
will run the test methods of the test object $test, unless "$test->SKIP_CLASS" returns a true value.
Unless you have already specified a test plan using Test::Builder (or Test::More, et al) "runtests"
will set the test plan just before the first method that runs a test is executed.
If the environment variable "TEST_VERBOSE" is set "runtests" will display the name of each test
method before it runs like this:
# My::Test::Class->my_test
ok 1 - fribble
# My::Test::Class->another_test
ok 2 - bar
Just like expected_tests(), "runtests" can take an optional list of test object/classes and integers.
All of the test object/classes are run. Any integers are added to the total number of tests shown in
the test header output by "runtests".
For example, you can run all the tests in test classes A, B and C, plus one additional normal test by
doing:
Test::Class->runtests(qw(A B C), +1);
ok(1==1, 'non class test');
Finally, if you call "runtests" on a test class without any arguments it will run all of the test
methods of that class, and all subclasses of that class. For example:
#! /usr/bin/perl
# Test all the Foo stuff
use Foo::Test;
use Foo::Bar::Test;
use Foo::Ni::Test;
# run all the Foo*Test modules we just loaded
Test::Class->runtests;
SKIP_CLASS
$reason = CLASS->SKIP_CLASS;
CLASS->SKIP_CLASS( $reason );
Determines whether the test class CLASS should run it's tests. If SKIP_CLASS returns a true value
then runtests() will not run any of the test methods in CLASS.
You can override the default on a class-by-class basis by supplying a new value to SKIP_CLASS. For
example if you have an abstract base class that should not run just add the following to your module:
My::Abstract::Test->SKIP_CLASS( 1 );
This will not affect any sub-classes of "My::Abstract::Test" which will run as normal.
If the true value returned by SKIP_CLASS is anything other than "1" then a skip test is output using
this value as the skip message. For example:
My::Postgres::Test->SKIP_CLASS(
$ENV{POSTGRES_HOME} ? 0 : '$POSTGRES_HOME needs to be set'
);
will output something like this if "POSTGRES_HOME" is not set
... other tests ...
ok 123 # skip My::Postgres::Test - $POSTGRES_HOME needs to be set
... more tests ...
You can also override SKIP_CLASS for a class hierarchy. For example, to prevent any subclasses of
My::Postgres::Test running we could override SKIP_CLASS like this:
sub My::Postgres::Test::SKIP_CLASS {
$ENV{POSTGRES_HOME} ? 0 : '$POSTGRES_HOME needs to be set'
}
Fetching and setting a method's test number
num_method_tests
$n = $Tests->num_method_tests($method_name)
$Tests->num_method_tests($method_name, $n)
$n = CLASS->num_method_tests($method_name)
CLASS->num_method_tests($method_name, $n)
Fetch or set the number of tests that the named method is expected to run.
If the method has an undetermined number of tests then $n should be the string "no_plan".
If the method is extending the number of tests run by the method in a superclass then $n should have
a "+" prefix.
When called as a class method any change to the expected number of tests applies to all future test
objects. Existing test objects are unaffected.
When called as an object method any change to the expected number of tests applies to that object
alone.
"num_method_tests" is useful when you need to set the expected number of tests at object creation
time, rather than at compile time.
For example, the following test class will run a different number of tests depending on the number of
objects supplied.
package Object::Test;
use base qw(Test::Class);
use Test::More;
sub new {
my $class = shift;
my $self = $class->SUPER::new(@_);
my $num_objects = @{$self->{objects}};
$self->num_method_tests('test_objects', $num_objects);
return($self);
}
sub test_objects : Tests {
my $self = shift;
ok($_->open, "opened $_") foreach @{$self->{objects}};
}
...
# This runs two tests
Object::Test->new(objects => [$o1, $o2]);
The advantage of setting the number of tests at object creation time, rather than using a test method
without a plan, is that the number of expected tests can be determined before testing begins. This
allows better diagnostics from runtests(), Test::Builder and Test::Harness.
"num_method_tests" is a protected method and can only be called by subclasses of Test::Class. It
fetches or sets the expected number of tests for the methods of the class it was called in, not the
methods of the object/class it was applied to. This allows test classes that use "num_method_tests"
to be subclassed easily.
For example, consider the creation of a subclass of Object::Test that ensures that all the opened
objects are read-only:
package Special::Object::Test;
use base qw(Object::Test);
use Test::More;
sub test_objects : Test(+1) {
my $self = shift;
$self->SUPER::test_objects;
my @bad_objects = grep {! $_->read_only} (@{$self->{objects}});
ok(@bad_objects == 0, "all objects read only");
}
...
# This runs three tests
Special::Object::Test->new(objects => [$o1, $o2]);
Since the call to "num_method_tests" in Object::Test only affects the "test_objects" of Object::Test,
the above works as you would expect.
num_tests
$n = $Tests->num_tests
$Tests->num_tests($n)
$n = CLASS->num_tests
CLASS->num_tests($n)
Set or return the number of expected tests associated with the currently running test method. This is
the same as calling num_method_tests() with a method name of current_method().
For example:
sub txt_files_readable : Tests {
my $self = shift;
my @files = <*.txt>;
$self->num_tests(scalar(@files));
ok(-r $_, "$_ readable") foreach (@files);
}
Setting the number of expected tests at run time, rather than just having a "no_plan" test method,
allows runtests() to display appropriate diagnostic messages if the method runs a different number of
tests.
Support methods
builder
$Tests->builder
Returns the underlying Test::Builder object that Test::Class uses. For example:
sub test_close : Test {
my $self = shift;
my ($o, $dbh) = ($self->{object}, $self->{dbh});
$self->builder->ok($o->close($dbh), "closed ok");
}
current_method
$method_name = $Tests->current_method
$method_name = CLASS->current_method
Returns the name of the test method currently being executed by runtests(), or "undef" if runtests()
has not been called.
The method name is also available in the setup and teardown methods that run before and after the
test method. This can be useful in producing diagnostic messages, for example:
sub test_invarient : Test(teardown => 1) {
my $self = shift;
my $m = $self->current_method;
ok($self->invarient_ok, "class okay after $m");
}
BAILOUT
$Tests->BAILOUT($reason)
CLASS->BAILOUT($reason)
Things are going so badly all testing should terminate, including running any additional test scripts
invoked by Test::Harness. This is exactly the same as doing:
$self->builder->BAILOUT
See "BAILOUT" in Test::Builder for details. Any teardown and shutdown methods are not run.
FAIL_ALL
$Tests->FAIL_ALL($reason)
CLASS->FAIL_ALL($reason)
Things are going so badly all the remaining tests in the current script should fail. Exits
immediately with the number of tests failed, or 254 if more than 254 tests were run. Any teardown
methods are not run.
This does not affect the running of any other test scripts invoked by Test::Harness.
For example, if all your tests rely on the ability to create objects then you might want something
like this as an early test:
sub _test_new : Test(3) {
my $self = shift;
isa_ok(Object->new, "Object")
|| $self->FAIL_ALL('cannot create Objects');
...
}
SKIP_ALL
$Tests->SKIP_ALL($reason)
CLASS->SKIP_ALL($reason)
Things are going so badly all the remaining tests in the current script should be skipped. Exits
immediately with 0 - teardown methods are not run.
This does not affect the running of any other test scripts invoked by Test::Harness.
For example, if you had a test script that only applied to the darwin OS you could write:
sub _darwin_only : Test(setup) {
my $self = shift;
$self->SKIP_ALL("darwin only") unless $^O eq "darwin";
}
add_testinfo
CLASS->add_testinfo($name, $type, $num_tests)
Chiefly for use by libraries like Test::Class::Sugar, which can't use the ":Test(...)" interfaces
make test methods. "add_testinfo" informs the class about a test method that has been defined without
a "Test", "Tests" or other attribute.
$name is the name of the method, $type must be one of "startup", "setup", "test", "teardown" or
"shutdown", and $num_tests has the same meaning as "N" in the description of the Test attribute.
add_filter
CLASS->add_filter($filter_coderef);
Adds a filtering coderef. Each filter is passed a test class and method name and returns a boolean.
All filters are applied globally in the order they were added. If any filter returns false the test
method is not run or included in the number of tests.
Note that filters will only be run for normal test methods, they are ignored for startup, shutdown,
setup, and teardown test methods.
See the section on the "GENERAL FILTERING OF TESTS" for more information.
fail_if_returned_early
Controls what happens if a method returns before it has run all of its tests. It is called with no
arguments in boolean context; if it returns true, then the missing tests fail, otherwise, they skip.
See "Returning Early" and "Skipped Tests".
fail_if_returned_late
Controls what happens if a method returns after running too many tests. It is called with no
arguments in boolean context; if it returns true, then the extra tests trigger a failure test. See
"Returning Late" and "Skipped Tests".
HELP FOR CONFUSED JUNIT USERS
This section is for people who have used JUnit (or similar) and are confused because they don't see the
TestCase/Suite/Runner class framework they were expecting. Here we take each of the major classes in
JUnit and compare them with their equivalent Perl testing modules.
Class Assert
The test assertions provided by Assert correspond to the test functions provided by the Test::Builder
based modules (Test::More, Test::Exception, Test::Differences, etc.)
Unlike JUnit the test functions supplied by Test::More et al do not throw exceptions on failure. They
just report the failure to STDOUT where it is collected by Test::Harness. This means that where you
have
sub foo : Test(2) {
ok($foo->method1);
ok($foo->method2);
}
The second test will run if the first one fails. You can emulate the JUnit way of doing it by
throwing an explicit exception on test failure:
sub foo : Test(2) {
ok($foo->method1) or die "method1 failed";
ok($foo->method2);
}
The exception will be caught by Test::Class and the other test automatically failed.
Class TestCase
Test::Class corresponds to TestCase in JUnit.
In Test::Class setup, test and teardown methods are marked explicitly using the Test attribute. Since
we need to know the total number of tests to provide a test plan for Test::Harness, we also state how
many tests each method runs.
Unlike JUnit you can have multiple setup/teardown methods in a class.
Class TestSuite
Test::Class also does the work that would be done by TestSuite in JUnit.
Since the methods are marked with attributes, Test::Class knows what is and isn't a test method. This
allows it to run all the test methods without having the developer create a suite manually, or use
reflection to dynamically determine the test methods by name. See the runtests() method for more
details.
The running order of the test methods is fixed in Test::Class. Methods are executed in alphabetical
order.
To run individual test methods, see "RUNNING INDIVIDUAL TESTS".
Class TestRunner
Test::Harness does the work of the TestRunner in JUnit. It collects the test results (sent to STDOUT)
and collates the results.
Unlike JUnit there is no distinction made by Test::Harness between errors and failures. However, it
does support skipped and todo test - which JUnit does not.
If you want to write your own test runners you should look at Test::Harness::Straps.
OTHER MODULES FOR XUNIT TESTING IN PERL
In addition to Test::Class there are two other distributions for xUnit testing in perl. Both have a
longer history than Test::Class and might be more suitable for your needs.
I am biased since I wrote Test::Class - so please read the following with appropriate levels of
scepticism. If you think I have misrepresented the modules please let me know.
Test::SimpleUnit
A very simple unit testing framework. If you are looking for a lightweight single module solution
this might be for you.
The advantage of Test::SimpleUnit is that it is simple! Just one module with a smallish API to learn.
Of course this is also the disadvantage.
It's not class based so you cannot create testing classes to reuse and extend.
It doesn't use Test::Builder so it's difficult to extend or integrate with other testing modules. If
you are already familiar with Test::Builder, Test::More and friends you will have to learn a new test
assertion API. It does not support todo tests.
Test::Unit
Test::Unit is a port of JUnit <http://www.junit.org/> into perl. If you have used JUnit then the
Test::Unit framework should be very familiar.
It is class based so you can easily reuse your test classes and extend by subclassing. You get a nice
flexible framework you can tweak to your heart's content. If you can run Tk you also get a graphical
test runner.
However, Test::Unit is not based on Test::Builder. You cannot easily move Test::Builder based test
functions into Test::Unit based classes. You have to learn another test assertion API.
Test::Unit implements it's own testing framework separate from Test::Harness. You can retrofit *.t
scripts as unit tests, and output test results in the format that Test::Harness expects, but things
like todo tests and skipping tests are not supported.
SUPPORT
Bugs may be submitted through GitHub issues <https://github.com/szabgab/test-class/issues>
There is also an irc channel available for users of this distribution, at "#perl-qa" on "irc.perl.org"
<irc://irc.perl.org/#perl-qa>.
TO DO
If you think this module should do something that it doesn't (or does something that it shouldn't) please
let me know.
You can see an old to do list at <http://adrianh.tadalist.com/lists/public/4798>, with an RSS feed of
changes at <http://adrianh.tadalist.com/lists/feed_public/4798>.
ACKNOWLEDGMENTS
This is yet another implementation of the ideas from Kent Beck's Testing Framework paper
<http://www.xprogramming.com/testfram.htm>.
Thanks to Adam Kennedy, agianni, Alexander D'Archangel, Andrew Grangaard, Apocalypse, Ask Bjorn Hansen,
Chris Dolan, Chris Williams, Corion, Cosimo Streppone, Daniel Berger, Dave Evans, Dave O'Neill, David
Cantrell, David Wheeler, Diab Jerius, Emil Jansson, Gunnar Wolf, Hai Pham, Hynek, imacat, Jeff Deifik,
Jim Brandt, Jochen Stenzel, Johan Lindstrom, John West, Jonathan R. Warden, Joshua ben Jore, Jost
Krieger, Ken Fox, Kenichi Ishigaki Lee Goddard, Mark Morgan, Mark Reynolds, Mark Stosberg, Martin
Ferrari, Mathieu Sauve-Frankel, Matt Trout, Matt Williamson, Michael G Schwern, Murat Uenalan, Naveed
Massjouni, Nicholas Clark, Ovid, Piers Cawley, Rob Kinyon, Sam Raymer, Scott Lanning, Sebastien Aperghis-
Tramoni, Steve Kirkup, Stray Toaster, Ted Carnahan, Terrence Brannon, Todd W, Tom Metro, Tony Bowden,
Tony Edwardson, William McKee, various anonymous folk and all the fine people on perl-qa for their
feedback, patches, suggestions and nagging.
This module wouldn't be possible without the excellent Test::Builder. Thanks to chromatic and Michael G
Schwern for creating such a useful module.
AUTHORS
Adrian Howard <adrianh@quietstars.com>, Curtis "Ovid" Poe, <ovid at cpan.org>, Mark Morgan
<makk384@gmail.com>.
SEE ALSO
Test::Class::Load
Simple way to load "Test::Class" classes automatically.
Test::Class::Most
Test::Class with additional conveniences to reduce need for some boilerplate code. Also makes
Test::Most testing functions available.
Test::Class::Moose
Testing framework allows you to write your tests in Moose and test Moose and non-Moose code. It
offers reporting, extensibility, test inheritance, parallel testing and more.
Perl Testing: A Developer's Notebook by Ian Langworth and chromatic
Chapter 8 covers using Test::Class.
Advanced Perl Programming, second edition by Simon Cozens
Chapter 8 has a few pages on using Test::Class.
The Perl Journal, April 2003
Includes the article "Test-Driven Development in Perl" by Piers Cawley that uses Test::Class.
Test::Class Tutorial series written by Curtis "Ovid" Poe
• Organizing Test Suites with Test::Class <http://www.modernperlbooks.com/mt/2009/03/organizing-
test-suites-with-testclass.html>
• Reusing Test Code with Test::Class <http://www.modernperlbooks.com/mt/2009/03/reusing-test-code-
with-testclass.html>
• Making Your Testing Life Easier <http://www.modernperlbooks.com/mt/2009/03/making-your-testing-
life-easier.html>
• Using Test Control Methods with Test::Class <http://www.modernperlbooks.com/mt/2009/03/using-
test-control-methods-with-testclass.html>
• Working with Test::Class Test Suites <http://www.modernperlbooks.com/mt/2009/03/working-with-
testclass-test-suites.html>
Test::Builder
Support module for building test libraries.
Test::Simple & Test::More
Basic utilities for writing tests.
<https://qa.perl.org/test-modules.html>
Overview of some of the many testing modules available on CPAN.
Test::Object
Another approach to object oriented testing.
Test::Group and Test::Block
Alternatives to grouping sets of tests together.
The following modules use Test::Class as part of their test suite. You might want to look at them for
usage examples:
App-GitGot, Aspect, Bricolage (<http://www.bricolage.cc/>), CHI, Cinnamon, Class::StorageFactory,
CGI::Application::Search, DBIx::Romani, Xmldoom, Object::Relational, File::Random,
Geography::JapanesePrefectures, Google::Adwords, Merge::HashRef, PerlBuildSystem, Ubic, Pixie,
Yahoo::Marketing, and XUL-Node
The following modules are not based on Test::Builder, but may be of interest as alternatives to
Test::Class.
Test::Unit
Perl unit testing framework closely modeled on JUnit.
Test::SimpleUnit
A very simple unit testing framework.
LICENCE
Copyright 2002-2010 Adrian Howard, All Rights Reserved.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl
itself.
perl v5.32.1 2021-02-20 Test::Class(3pm)