Test::Builder(3p)Perl Programmers Reference GuidTest::Builder(3p)
Test::Builder - Backend for building test libraries
package My::Test::Module;
use Test::Builder;
require Exporter;
@ISA = qw(Exporter);
@EXPORT = qw(ok);
my $Test = Test::Builder->new;
$Test->output('my_logfile');
sub import {
my($self) = shift;
my $pack = caller;
$Test->exported_to($pack);
$Test->plan(@_);
$self->export_to_level(1, $self, 'ok');
}
sub ok {
my($test, $name) = @_;
$Test->ok($test, $name);
}
Test::Simple and Test::More have proven to be popular test-
ing modules, but they're not always flexible enough.
Test::Builder provides the a building block upon which to
write your own test libraries which can work together.
Construction
new
my $Test = Test::Builder->new;
Returns a Test::Builder object representing the current
state of the test.
Since you only run one test per program "new" always
returns the same Test::Builder object. No matter how
many times you call new(), you're getting the same
object. This is called a singleton. This is done so
that multiple modules share such global information as
the test counter and where test output is going.
If you want a completely new Test::Builder object dif-
ferent from the singleton, use "create".
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create
my $Test = Test::Builder->create;
Ok, so there can be more than one Test::Builder object
and this is how you get it. You might use this instead
of "new()" if you're testing a Test::Builder based
module, but otherwise you probably want "new".
NOTE: the implementation is not complete. "level", for
example, is still shared amongst all Test::Builder
objects, even ones created using this method. Also, the
method name may change in the future.
reset
$Test->reset;
Reinitializes the Test::Builder singleton to its origi-
nal state. Mostly useful for tests run in persistent
environments where the same test might be run multiple
times in the same process.
Setting up tests
These methods are for setting up tests and declaring how
many there are. You usually only want to call one of these
methods.
exported_to
my $pack = $Test->exported_to;
$Test->exported_to($pack);
Tells Test::Builder what package you exported your func-
tions to. This is important for getting TODO tests
right.
plan
$Test->plan('no_plan');
$Test->plan( skip_all => $reason );
$Test->plan( tests => $num_tests );
A convenient way to set up your tests. Call this and
Test::Builder will print the appropriate headers and
take the appropriate actions.
If you call plan(), don't call any of the other methods
below.
expected_tests
my $max = $Test->expected_tests;
$Test->expected_tests($max);
Gets/sets the # of tests we expect this test to run and
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prints out the appropriate headers.
no_plan
$Test->no_plan;
Declares that this test will run an indeterminate # of
tests.
has_plan
$plan = $Test->has_plan
Find out whether a plan has been defined. $plan is
either "undef" (no plan has been set), "no_plan"
(indeterminate # of tests) or an integer (the number of
expected tests).
skip_all
$Test->skip_all;
$Test->skip_all($reason);
Skips all the tests, using the given $reason. Exits
immediately with 0.
Running tests
These actually run the tests, analogous to the functions in
Test::More.
$name is always optional.
ok
$Test->ok($test, $name);
Your basic test. Pass if $test is true, fail if $test
is false. Just like Test::Simple's ok().
is_eq
$Test->is_eq($got, $expected, $name);
Like Test::More's is(). Checks if $got eq $expected.
This is the string version.
is_num
$Test->is_num($got, $expected, $name);
Like Test::More's is(). Checks if $got == $expected.
This is the numeric version.
isnt_eq
$Test->isnt_eq($got, $dont_expect, $name);
Like Test::More's isnt(). Checks if $got ne
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$dont_expect. This is the string version.
isnt_num
$Test->is_num($got, $dont_expect, $name);
Like Test::More's isnt(). Checks if $got ne
$dont_expect. This is the numeric version.
like
$Test->like($this, qr/$regex/, $name);
$Test->like($this, '/$regex/', $name);
Like Test::More's like(). Checks if $this matches the
given $regex.
You'll want to avoid qr// if you want your tests to work
before 5.005.
unlike
$Test->unlike($this, qr/$regex/, $name);
$Test->unlike($this, '/$regex/', $name);
Like Test::More's unlike(). Checks if $this does not
match the given $regex.
maybe_regex
$Test->maybe_regex(qr/$regex/);
$Test->maybe_regex('/$regex/');
Convenience method for building testing functions that
take regular expressions as arguments, but need to work
before perl 5.005.
Takes a quoted regular expression produced by qr//, or a
string representing a regular expression.
Returns a Perl value which may be used instead of the
corresponding regular expression, or undef if it's argu-
ment is not recognised.
For example, a version of like(), sans the useful diag-
nostic messages, could be written as:
sub laconic_like {
my ($self, $this, $regex, $name) = @_;
my $usable_regex = $self->maybe_regex($regex);
die "expecting regex, found '$regex'\n"
unless $usable_regex;
$self->ok($this =~ m/$usable_regex/, $name);
}
cmp_ok
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$Test->cmp_ok($this, $type, $that, $name);
Works just like Test::More's cmp_ok().
$Test->cmp_ok($big_num, '!=', $other_big_num);
BAIL_OUT
$Test->BAIL_OUT($reason);
Indicates to the Test::Harness that things are going so
badly all testing should terminate. This includes run-
ning any additional test scripts.
It will exit with 255.
skip
$Test->skip;
$Test->skip($why);
Skips the current test, reporting $why.
todo_skip
$Test->todo_skip;
$Test->todo_skip($why);
Like skip(), only it will declare the test as failing
and TODO. Similar to
print "not ok $tnum # TODO $why\n";
Test style
level
$Test->level($how_high);
How far up the call stack should $Test look when report-
ing where the test failed.
Defaults to 1.
Setting $Test::Builder::Level overrides. This is typi-
cally useful localized:
{
local $Test::Builder::Level = 2;
$Test->ok($test);
}
use_numbers
$Test->use_numbers($on_or_off);
Whether or not the test should output numbers. That is,
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this if true:
ok 1
ok 2
ok 3
or this if false
ok
ok
ok
Most useful when you can't depend on the test output
order, such as when threads or forking is involved.
Test::Harness will accept either, but avoid mixing the
two styles.
Defaults to on.
no_diag
$Test->no_diag($no_diag);
If set true no diagnostics will be printed. This
includes calls to diag().
no_ending
$Test->no_ending($no_ending);
Normally, Test::Builder does some extra diagnostics when
the test ends. It also changes the exit code as
described below.
If this is true, none of that will be done.
no_header
$Test->no_header($no_header);
If set to true, no "1..N" header will be printed.
Output
Controlling where the test output goes.
It's ok for your test to change where STDOUT and STDERR
point to, Test::Builder's default output settings will not
be affected.
diag
$Test->diag(@msgs);
Prints out the given @msgs. Like "print", arguments are
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simply appended together.
Normally, it uses the failure_output() handle, but if
this is for a TODO test, the todo_output() handle is
used.
Output will be indented and marked with a # so as not to
interfere with test output. A newline will be put on
the end if there isn't one already.
We encourage using this rather than calling print
directly.
Returns false. Why? Because diag() is often used in
conjunction with a failing test ("ok() || diag()") it
"passes through" the failure.
return ok(...) || diag(...);
_print_diag
$Test->_print_diag(@msg);
Like _print, but prints to the current diagnostic
filehandle.
output
$Test->output($fh);
$Test->output($file);
Where normal "ok/not ok" test output should go.
Defaults to STDOUT.
failure_output
$Test->failure_output($fh);
$Test->failure_output($file);
Where diagnostic output on test failures and diag()
should go.
Defaults to STDERR.
todo_output
$Test->todo_output($fh);
$Test->todo_output($file);
Where diagnostics about todo test failures and diag()
should go.
Defaults to STDOUT.
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Test Status and Info
current_test
my $curr_test = $Test->current_test;
$Test->current_test($num);
Gets/sets the current test number we're on. You usually
shouldn't have to set this.
If set forward, the details of the missing tests are
filled in as 'unknown'. if set backward, the details of
the intervening tests are deleted. You can erase his-
tory if you really want to.
summary
my @tests = $Test->summary;
A simple summary of the tests so far. True for pass,
false for fail. This is a logical pass/fail, so todos
are passes.
Of course, test #1 is $tests[0], etc...
details
my @tests = $Test->details;
Like summary(), but with a lot more detail.
$tests[$test_num - 1] =
{ 'ok' => is the test considered a pass?
actual_ok => did it literally say 'ok'?
name => name of the test (if any)
type => type of test (if any, see below).
reason => reason for the above (if any)
};
'ok' is true if Test::Harness will consider the test to
be a pass.
'actual_ok' is a reflection of whether or not the test
literally printed 'ok' or 'not ok'. This is for examin-
ing the result of 'todo' tests.
'name' is the name of the test.
'type' indicates if it was a special test. Normal tests
have a type of ''. Type can be one of the following:
skip see skip()
todo see todo()
todo_skip see todo_skip()
unknown see below
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Sometimes the Test::Builder test counter is incremented
without it printing any test output, for example, when
current_test() is changed. In these cases, Test::Builder
doesn't know the result of the test, so it's type is
'unkown'. These details for these tests are filled in.
They are considered ok, but the name and actual_ok is
left undef.
For example "not ok 23 - hole count # TODO insufficient
donuts" would result in this structure:
$tests[22] = # 23 - 1, since arrays start from 0.
{ ok => 1, # logically, the test passed since it's todo
actual_ok => 0, # in absolute terms, it failed
name => 'hole count',
type => 'todo',
reason => 'insufficient donuts'
};
todo
my $todo_reason = $Test->todo;
my $todo_reason = $Test->todo($pack);
todo() looks for a $TODO variable in your tests. If
set, all tests will be considered 'todo' (see Test::More
and Test::Harness for details). Returns the reason (ie.
the value of $TODO) if running as todo tests, false oth-
erwise.
todo() is about finding the right package to look for
$TODO in. It uses the exported_to() package to find it.
If that's not set, it's pretty good at guessing the
right package to look at based on $Level.
Sometimes there is some confusion about where todo()
should be looking for the $TODO variable. If you want
to be sure, tell it explicitly what $pack to use.
caller
my $package = $Test->caller;
my($pack, $file, $line) = $Test->caller;
my($pack, $file, $line) = $Test->caller($height);
Like the normal caller(), except it reports according to
your level().
If all your tests passed, Test::Builder will exit with zero
(which is normal). If anything failed it will exit with how
many failed. If you run less (or more) tests than you
planned, the missing (or extras) will be considered
failures. If no tests were ever run Test::Builder will
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throw a warning and exit with 255. If the test died, even
after having successfully completed all its tests, it will
still be considered a failure and will exit with 255.
So the exit codes are...
0 all tests successful
255 test died or all passed but wrong # of tests run
any other number how many failed (including missing or extras)
If you fail more than 254 tests, it will be reported as 254.
In perl 5.8.0 and later, Test::Builder is thread-safe. The
test number is shared amongst all threads. This means if
one thread sets the test number using current_test() they
will all be effected.
Test::Builder is only thread-aware if threads.pm is loaded
before Test::Builder.
CPAN can provide the best examples. Test::Simple,
Test::More, Test::Exception and Test::Differences all use
Test::Builder.
Test::Simple, Test::More, Test::Harness
Original code by chromatic, maintained by Michael G Schwern
<schwern@pobox.com>
Copyright 2002, 2004 by chromatic <chromatic@wgz.org> and
Michael G Schwern
<schwern@pobox.com>.
This program is free software; you can redistribute it
and/or modify it under the same terms as Perl itself.
See http://www.perl.com/perl/misc/Artistic.html
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