Test::Builder
Test::Builder(3) User Contributed Perl Documentation Test::Builder(3)
NAME
Test::Builder - Backend for building test libraries
SYNOPSIS
package My::Test::Module;
use base ’Test::Builder::Module’;
my $CLASS = __PACKAGE__;
sub ok {
my($test, $name) = @_;
my $tb = $CLASS->builder;
$tb->ok($test, $name);
}
DESCRIPTION
Test::Simple and Test::More have proven to be popular testing 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 single-
ton. 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 different from
the singleton, use "create".
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 cre-
ated using this method. Also, the method name may change in the
future.
reset
$Test->reset;
Reinitializes the Test::Builder singleton to its original 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.
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 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.
exported_to
my $pack = $Test->exported_to;
$Test->exported_to($pack);
Tells Test::Builder what package you exported your functions to.
This method isn’t terribly useful since modules which share the
same Test::Builder object might get exported to different packages
and only the last one will be honored.
Running tests
These actually run the tests, analogous to the functions in
Test::More.
They all return true if the test passed, false if the test failed.
$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 $dont_expect. This
is the string version.
isnt_num
$Test->isnt_num($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.
cmp_ok
$Test->cmp_ok($this, $type, $that, $name);
Works just like Test::More’s cmp_ok().
$Test->cmp_ok($big_num, ’!=’, $other_big_num);
Other Testing Methods
These are methods which are used in the course of writing a test but
are not themselves tests.
BAIL_OUT
$Test->BAIL_OUT($reason);
Indicates to the Test::Harness that things are going so badly all
testing should terminate. This includes running 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 building utility methods
These methods are useful when writing your own test methods.
maybe_regex
$Test->maybe_regex(qr/$regex/);
$Test->maybe_regex(’/$regex/’);
Convenience method for building testing functions that take regu-
lar 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 correspond-
ing regular expression, or undef if its argument is not recog-
nised.
For example, a version of like(), sans the useful diagnostic mes-
sages, 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);
}
is_fh
my $is_fh = $Test->is_fh($thing);
Determines if the given $thing can be used as a filehandle.
Test style
level
$Test->level($how_high);
How far up the call stack should $Test look when reporting where
the test failed.
Defaults to 1.
Setting $Test::Builder::Level overrides. This is typically useful
localized:
sub my_ok {
my $test = shift;
local $Test::Builder::Level = $Test::Builder::Level + 1;
$TB->ok($test);
}
To be polite to other functions wrapping your own you usually want
to increment $Level rather than set it to a constant.
use_numbers
$Test->use_numbers($on_or_off);
Whether or not the test should output numbers. That is, 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.
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 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(...);
note
$Test->note(@msgs);
Like diag(), but it prints to the "output()" handle so it will not
normally be seen by the user except in verbose mode.
explain
my @dump = $Test->explain(@msgs);
Will dump the contents of any references in a human readable for-
mat. Handy for things like...
is_deeply($have, $want) ││ diag explain $have;
or
is_deeply($have, $want) ││ note explain $have;
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.
reset_outputs
$tb->reset_outputs;
Resets all the output filehandles back to their defaults.
carp
$tb->carp(@message);
Warns with @message but the message will appear to come from the
point where the original test function was called ("$tb-"caller>).
croak
$tb->croak(@message);
Dies with @message but the message will appear to come from the
point where the original test function was called ("$tb-"caller>).
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 history 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 examining 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
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 its type is ’unknown’. 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);
If the current tests are considered "TODO" it will return the rea-
son, if any. This reason can come from a $TODO variable or the
last call to "<todo_start()">.
Since a TODO test does not need a reason, this function can return
an empty string even when inside a TODO block. Use
"<$Test-"in_todo>> to determine if you are currently inside a TODO
block.
todo() is about finding the right package to look for $TODO in.
It’s pretty good at guessing the right package to look at. It
first looks for the caller based on "$Level + 1", since "todo()"
is usually called inside a test function. As a last resort it
will use "exported_to()".
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.
find_TODO
my $todo_reason = $Test->find_TODO();
my $todo_reason = $Test->find_TODO($pack):
Like "<todo()"> but only returns the value of "<$TODO"> ignoring
"<todo_start()">.
in_todo
my $in_todo = $Test->in_todo;
Returns true if the test is currently inside a TODO block.
todo_start
$Test->todo_start();
$Test->todo_start($message);
This method allows you declare all subsequent tests as TODO tests,
up until the "todo_end" method has been called.
The "TODO:" and $TODO syntax is generally pretty good about figur-
ing out whether or not we’re in a TODO test. However, often we
find that this is not possible to determine (such as when we want
to use $TODO but the tests are being executed in other packages
which can’t be inferred beforehand).
Note that you can use this to nest "todo" tests
$Test->todo_start(’working on this’);
# lots of code
$Test->todo_start(’working on that’);
# more code
$Test->todo_end;
$Test->todo_end;
This is generally not recommended, but large testing systems often
have weird internal needs.
We’ve tried to make this also work with the TODO: syntax, but it’s
not guaranteed and its use is also discouraged:
TODO: {
local $TODO = ’We have work to do!’;
$Test->todo_start(’working on this’);
# lots of code
$Test->todo_start(’working on that’);
# more code
$Test->todo_end;
$Test->todo_end;
}
Pick one style or another of "TODO" to be on the safe side.
"todo_end"
$Test->todo_end;
Stops running tests as "TODO" tests. This method is fatal if
called without a preceding "todo_start" method call.
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().
$height will be added to the level().
If caller() winds up off the top of the stack it report the high-
est context.
EXIT CODES
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 throw a warning and exit with 255. If the test died, even after
having successfully completed all its tests, it will still be consid-
ered 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.
THREADS
In perl 5.8.1 and later, Test::Builder is thread-safe. The test num-
ber is shared amongst all threads. This means if one thread sets the
test number using current_test() they will all be effected.
While versions earlier than 5.8.1 had threads they contain too many
bugs to support.
Test::Builder is only thread-aware if threads.pm is loaded before
Test::Builder.
EXAMPLES
CPAN can provide the best examples. Test::Simple, Test::More,
Test::Exception and Test::Differences all use Test::Builder.
SEE ALSO
Test::Simple, Test::More, Test::Harness
AUTHORS
Original code by chromatic, maintained by Michael G Schwern <schw-
ern@pobox.com>
COPYRIGHT
Copyright 2002-2008 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
perl v5.8.8 2008-11-09 Test::Builder(3)
