test::more(3)

NAME

Test::More - yet another framework for writing test
scripts

SYNOPSIS

use Test::More tests => $Num_Tests;
# or
use Test::More qw(no_plan);
# or
use Test::More skip_all => $reason;
BEGIN { use_ok( 'Some::Module' ); }
require_ok( 'Some::Module' );
# Various ways to say "ok"
ok($this eq $that, $test_name);
is  ($this, $that,    $test_name);
isnt($this, $that,    $test_name);
# Rather than print STDERR "# here's what went wrong0
diag("here's what went wrong");
like  ($this, qr/that/, $test_name);
unlike($this, qr/that/, $test_name);
cmp_ok($this, '==', $that, $test_name);
is_deeply($complex_structure1,      $complex_structure2,
$test_name);
SKIP: {
    skip $why, $how_many unless $have_some_feature;
    ok( foo(),       $test_name );
    is( foo(42), 23, $test_name );
};
TODO: {
    local $TODO = $why;
    ok( foo(),       $test_name );
    is( foo(42), 23, $test_name );
};
can_ok($module, @methods);
isa_ok($object, $class);
pass($test_name);
fail($test_name);
# Utility comparison functions.
eq_array(@this, @that);
eq_hash(this, that);
eq_set(@this, @that);
# UNIMPLEMENTED!!!
my @status = Test::More::status;
# UNIMPLEMENTED!!!
BAIL_OUT($why);

DESCRIPTION

STOP! If you're just getting started writing tests, have a
look at Test::Simple first. This is a drop in replacement
for Test::Simple which you can switch to once you get the
hang of basic testing.

The purpose of this module is to provide a wide range of
testing utilities. Various ways to say "ok" with better
diagnostics, facilities to skip tests, test future fea
tures and compare complicated data structures. While you
can do almost anything with a simple "ok()" function, it
doesn't provide good diagnostic output.

I love it when a plan comes together

Before anything else, you need a testing plan. This basi
cally declares how many tests your script is going to run
to protect against premature failure.

The preferred way to do this is to declare a plan when you "use Test::More".: use Test::More tests => $Num_Tests;
There are rare cases when you will not know beforehand how many tests your script is going to run. In this case, you can declare that you have no plan. (Try to avoid using this as it weakens your test.): use Test::More qw(no_plan);
In some cases, you'll want to completely skip an entire testing script.: use Test::More skip_all => $skip_reason;
Your script will declare a skip with the reason why you skipped and exit immediately with a zero (success). See Test::Harness for details.
If you want to control what functions Test::More will export, you have to use the 'import' option. For example, to import everything but 'fail', you'd do:: use Test::More tests => 23, import => ['!fail'];
Alternatively, you can use the plan() function. Useful for when you have to calculate the number of tests.: use Test::More;
plan tests => keys %Stuff * 3;
or for deciding between running the tests at all:: use Test::More;
if( $^O eq 'MacOS' ) {
plan skip_all => 'Test irrelevant on MacOS';; }
else {
plan tests => 42;; }
Test names
By convention, each test is assigned a number in order. This is largely done automatically for you. However, it's often very useful to assign a name to each test. Which would you rather see:: ok 4
not ok 5
ok 6
or: ok 4 - basic multi-variable
not ok 5 - simple exponential
ok 6 - force == mass * acceleration
The later gives you some idea of what failed. It also makes it easier to find the test in your script, simply search for "simple exponential".
All test functions take a name argument. It's optional, but highly suggested that you use it.
I'm ok, you're not ok.
The basic purpose of this module is to print out either "ok #" or "not ok #" depending on if a given test suc ceeded or failed. Everything else is just gravy.
All of the following print "ok" or "not ok" depending on if the test succeeded or failed. They all also return true or false, respectively.
ok: ok($this eq $that, $test_name);
This simply evaluates any expression ("$this eq $that" is just a simple example) and uses that to determine if the test succeeded or failed. A true expression passes, a false one fails. Very simple.
For example:: ok( $exp{9} == 81, 'simple expo; nential' );
ok( Film->can('db_Main'), 'set_db()' );
ok( $p->tests == 4, 'saw tests'; );
ok( !grep !defined $_, @items, 'items popu; lated' );
(Mnemonic: "This is ok.")
$test_name is a very short description of the test
that will be printed out. It makes it very easy to
find a test in your script when it fails and gives
others an idea of your intentions. $test_name is
optional, but we very strongly encourage its use.
Should an ok() fail, it will produce some diagnostics:: not ok 18 - sufficient mucus
# Failed test 18 (foo.t at line 42)
This is actually Test::Simple's ok() routine.
is
isnt: is ( $this, $that, $test_name );
isnt( $this, $that, $test_name );
Similar to ok(), is() and isnt() compare their two arguments with "eq" and "ne" respectively and use the result of that to determine if the test succeeded or failed. So these:: # Is the ultimate answer 42?
is( ultimate_answer(), 42, "Meaning of; Life" );; # $foo isn't empty
isnt( $foo, '', "Got some foo" );
are similar to these:: ok( ultimate_answer() eq 42, "Meaning of; Life" );
ok( $foo ne '', "Got some foo" );
(Mnemonic: "This is that." "This isn't that.")
So why use these? They produce better diagnostics on failure. ok() cannot know what you are testing for (beyond the name), but is() and isnt() know what the test was and why it failed. For example this test:: my $foo = 'waffle'; my $bar = 'yarblokos';
is( $foo, $bar, 'Is foo the same as bar?' );
Will produce something like this:: not ok 17 - Is foo the same as bar?
# Failed test 1 (foo.t at line 139)
# got: 'waffle'
# expected: 'yarblokos'
So you can figure out what went wrong without rerun ning the test.
You are encouraged to use is() and isnt() over ok() where possible, however do not be tempted to use them to find out if something is true or false!: # XXX BAD! $pope->isa('Catholic') eq 1
is( $pope->isa('Catholic'), 1, 'Is the Pope; Catholic?' );
This does not check if "$pope-"isa('Catholic')> is true, it checks if it returns 1. Very different. Similar caveats exist for false and 0. In these cases, use ok().: ok( $pope->isa('Catholic') ), 'Is the Pope; Catholic?' );
For those grammatical pedants out there, there's an "isn't()" function which is an alias of isnt().
like: like( $this, qr/that/, $test_name );
Similar to ok(), like() matches $this against the regex "qr/that/".
So this:: like($this, qr/that/, 'this is like that');
is similar to:: ok( $this =~ /that/, 'this is like that');
(Mnemonic "This is like that".)
The second argument is a regular expression. It may be given as a regex reference (i.e. "qr//") or (for better compatibility with older perls) as a string that looks like a regex (alternative delimiters are currently not supported):: like( $this, '/that/', 'this is like that' );
Regex options may be placed on the end ('/that/i').
Its advantages over ok() are similar to that of is() and isnt(). Better diagnostics on failure.
unlike: unlike( $this, qr/that/, $test_name );
Works exactly as like(), only it checks if $this does not match the given pattern.
cmp_ok: cmp_ok( $this, $op, $that, $test_name );
Halfway between ok() and is() lies cmp_ok(). This allows you to compare two arguments using any binary
perl operator.: # ok( $this eq $that );
cmp_ok( $this, 'eq', $that, 'this eq that' );; # ok( $this == $that );
cmp_ok( $this, '==', $that, 'this == that' );; # ok( $this && $that );
cmp_ok( $this, '&&', $that, 'this || that' );
...etc...
Its advantage over ok() is when the test fails you'll know what $this and $that were:: not ok 1
# Failed test (foo.t at line 12)
# '23'
# &&
# undef
It's also useful in those cases where you are compar ing numbers and is()'s use of "eq" will interfere:: cmp_ok( $big_hairy_number, '==', $anoth; er_big_hairy_number );
can_ok: can_ok($module, @methods);
can_ok($object, @methods);
Checks to make sure the $module or $object can do these @methods (works with functions, too).: can_ok('Foo', qw(this that whatever));
is almost exactly like saying:: ok( Foo->can('this') &&
Foo->can('that') &&
Foo->can('whatever'); );
only without all the typing and with a better inter face. Handy for quickly testing an interface.
No matter how many @methods you check, a single
can_ok() call counts as one test. If you desire oth erwise, use:: foreach my $meth (@methods) {
can_ok('Foo', $meth);; }
isa_ok: isa_ok($object, $class, $object_name);
isa_ok($ref, $type, $ref_name);
Checks to see if the given $object->isa($class). Also checks to make sure the object was defined in the first place. Handy for this sort of thing:: my $obj = Some::Module->new;
isa_ok( $obj, 'Some::Module' );
where you'd otherwise have to write: my $obj = Some::Module->new;
ok( defined $obj && $obj->isa('Some::Module') );
to safeguard against your test script blowing up.
It works on references, too:: isa_ok( $array_ref, 'ARRAY' );
The diagnostics of this test normally just refer to 'the object'. If you'd like them to be more specific, you can supply an $object_name (for example 'Test cus tomer').
pass
fail: pass($test_name);
fail($test_name);
Sometimes you just want to say that the tests have passed. Usually the case is you've got some compli cated condition that is difficult to wedge into an ok(). In this case, you can simply use pass() (to declare the test ok) or fail (for not ok). They are synonyms for ok(1) and ok(0).
Use these very, very, very sparingly.
Diagnostics
If you pick the right test function, you'll usually get a good idea of what went wrong when it failed. But some times it doesn't work out that way. So here we have ways for you to write your own diagnostic messages which are safer than just "print STDERR".
diag: diag(@diagnostic_message);
Prints a diagnostic message which is guaranteed not to interfere with test output. Handy for this sort of thing:: ok( grep(/foo/, @users), "There's a foo user" ) or
diag("Since there's no foo, check that

/etc/bar is set up right");
which would produce:: not ok 42 - There's a foo user
# Failed test (foo.t at line 52)
# Since there's no foo, check that /etc/bar is set; up right.
You might remember "ok() or diag()" with the mnemonic "open() or die()".
NOTE The exact formatting of the diagnostic output is
still changing, but it is guaranteed that whatever you
throw at it it won't interfere with the test.
Module tests
You usually want to test if the module you're testing loads ok, rather than just vomiting if its load fails. For such purposes we have "use_ok" and "require_ok".
use_ok: BEGIN { use_ok($module); }
BEGIN { use_ok($module, @imports); }
These simply use the given $module and test to make
sure the load happened ok. It's recommended that you
run use_ok() inside a BEGIN block so its functions are exported at compile-time and prototypes are properly
honored.
If @imports are given, they are passed through to the use. So this:: BEGIN { use_ok('Some::Module', qw(foo bar)) }
is like doing this:: use Some::Module qw(foo bar);
don't try to do this:: BEGIN {
use_ok('Some::Module');

...some code that depends on the use...
...happening at compile time...; }
instead, you want:: BEGIN { use_ok('Some::Module') }
BEGIN { ...some code that depends on the use... }
require_ok: require_ok($module);
Like use_ok(), except it requires the $module.
Conditional tests
Sometimes running a test under certain conditions will cause the test script to die. A certain function or method isn't implemented (such as fork() on MacOS), some resource isn't available (like a net connection) or a mod ule isn't available. In these cases it's necessary to skip tests, or declare that they are supposed to fail but will work in the future (a todo test).
For more details on the mechanics of skip and todo tests see Test::Harness.
The way Test::More handles this is with a named block. Basically, a block of tests which can be skipped over or made todo. It's best if I just show you...
SKIP: BLOCK: SKIP: {
skip $why, $how_many if $condition;

...normal testing code goes here...; }
This declares a block of tests that might be skipped, $how_many tests there are, $why and under what $condi tion to skip them. An example is the easiest way to illustrate:: SKIP: {
eval { require HTML::Lint };

skip "HTML::Lint not installed", 2 if $@;

my $lint = new HTML::Lint;
isa_ok( $lint, "HTML::Lint" );

$lint->parse( $html );
is( $lint->errors, 0, "No errors found in

HTML" );; }
If the user does not have HTML::Lint installed, the whole block of code won't be run at all. Test::More will output special ok's which Test::Harness inter prets as skipped, but passing, tests. It's important that $how_many accurately reflects the number of tests in the SKIP block so the # of tests run will match up with your plan.
It's perfectly safe to nest SKIP blocks. Each SKIP block must have the label "SKIP", or Test::More can't work its magic.
You don't skip tests which are failing because there's a bug in your program, or for which you don't yet have code written. For that you use TODO. Read on.
TODO: BLOCK: TODO: {
local $TODO = $why if $condition;

...normal testing code goes here...; }
Declares a block of tests you expect to fail and $why. Perhaps it's because you haven't fixed a bug or haven't finished a new feature:: TODO: {
local $TODO = "URI::Geller not finished";

my $card = "Eight of clubs";
is( URI::Geller->your_card, $card, 'Is THIS

your card?' );

my $spoon;
URI::Geller->bend_spoon;
is( $spoon, 'bent', "Spoon bending, that's

original" );; }
With a todo block, the tests inside are expected to fail. Test::More will run the tests normally, but print out special flags indicating they are "todo". Test::Harness will interpret failures as being ok. Should anything succeed, it will report it as an unex pected success. You then know the thing you had todo is done and can remove the TODO flag.
The nice part about todo tests, as opposed to simply commenting out a block of tests, is it's like having a programmatic todo list. You know how much work is left to be done, you're aware of what bugs there are, and you'll know immediately when they're fixed.
Once a todo test starts succeeding, simply move it outside the block. When the block is empty, delete it.
todo_skip: TODO: {
todo_skip $why, $how_many if $condition;

...normal testing code...; }
With todo tests, it's best to have the tests actually run. That way you'll know when they start passing. Sometimes this isn't possible. Often a failing test will cause the whole program to die or hang, even inside an "eval BLOCK" with and using "alarm". In these extreme cases you have no choice but to skip over the broken tests entirely.
The syntax and behavior is similar to a "SKIP: BLOCK" except the tests will be marked as failing but todo. Test::Harness will interpret them as passing.
When do I use SKIP vs. TODO?: If it's something the user might not be able to do, use SKIP. This includes optional modules that aren't
installed, running under an OS that doesn't have some
feature (like fork() or symlinks), or maybe you need
an Internet connection and one isn't available.; If it's something the programmer hasn't done yet, use TODO. This is for any code you haven't written yet,
or bugs you have yet to fix, but want to put tests in
your testing script (always a good idea).
Comparison functions
Not everything is a simple eq check or regex. There are times you need to see if two arrays are equivalent, for instance. For these instances, Test::More provides a handful of useful functions.
NOTE These are NOT well-tested on circular references.
Nor am I quite sure what will happen with filehandles.
is_deeply: is_deeply( $this, $that, $test_name );
Similar to is(), except that if $this and $that are hash or array references, it does a deep comparison walking each data structure to see if they are equiva lent. If the two structures are different, it will display the place where they start differing.
Barrie Slaymaker's Test::Differences module provides more in-depth functionality along these lines, and it plays well with Test::More.
NOTE Display of scalar refs is not quite 100%
eq_array: eq_array(@this, @that);
Checks if two arrays are equivalent. This is a deep check, so multi-level structures are handled cor rectly.
eq_hash: eq_hash(this, that);
Determines if the two hashes contain the same keys and values. This is a deep check.
eq_set: eq_set(@this, @that);
Similar to eq_array(), except the order of the ele ments is not important. This is a deep check, but the
irrelevancy of order only applies to the top level.
NOTE By historical accident, this is not a true set
comparision. While the order of elements does not
matter, duplicate elements do.
Extending and Embedding Test::More
Sometimes the Test::More interface isn't quite enough.
Fortunately, Test::More is built on top of Test::Builder
which provides a single, unified backend for any test
library to use. This means two test libraries which both
use Test::Builder can be used together in the same pro gram.
If you simply want to do a little tweaking of how the tests behave, you can access the underlying Test::Builder object like so:
builder: my $test_builder = Test::More->builder;
Returns the Test::Builder object underlying Test::More for you to play with.

NOTES

Test::More is explicitly tested all the way back to perl 5.004.

Test::More is thread-safe for perl 5.8.0 and up.

BUGS and CAVEATS

Making your own ok(): If you are trying to extend Test::More, don't. Use
Test::Builder instead.
The eq_* family has some caveats. Test::Harness upgrades: no_plan and todo depend on new Test::Harness features
and fixes. If you're going to distribute tests that
use no_plan or todo your end-users will have to
upgrade Test::Harness to the latest one on CPAN. If
you avoid no_plan and TODO tests, the stock Test::Har
ness will work fine.; If you simply depend on Test::More, it's own dependen
cies will cause a Test::Harness upgrade.

HISTORY

This is a case of convergent evolution with Joshua Pri
tikin's Test module. I was largely unaware of its exis
tence when I'd first written my own ok() routines. This
module exists because I can't figure out how to easily
wedge test names into Test's interface (along with a few
other problems).

The goal here is to have a testing utility that's simple
to learn, quick to use and difficult to trip yourself up
with while still providing more flexibility than the
existing Test.pm. As such, the names of the most common
routines are kept tiny, special cases and magic sideeffects are kept to a minimum. WYSIWYG.

AUTHORS

Michael G Schwern <schwern@pobox.com> with much inspira
tion from Joshua Pritikin's Test module and lots of help
from Barrie Slaymaker, Tony Bowden, chromatic and the
perl-qa gang.

COPYRIGHT

This program is free software; you can redistribute it
and/or modify it under the same terms as Perl itself.

docs.sk

comprehensive documentation repository

In section