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Test::Builder(3) |
User Contributed Perl Documentation |
Test::Builder(3) |
Test::Builder - Backend for building test libraries
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);
}
Test::Simple and Test::More have proven to be popular testing
modules, but they're not always flexible enough. Test::Builder provides a
building block upon which to write your own test libraries which can
work together.
- 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 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
by all Test::Builder objects, even ones created using this
method. Also, the method name may change in the future.
- subtest
-
$builder->subtest($name, \&subtests, @args);
See documentation of
"subtest" in Test::More.
"subtest" also, and
optionally, accepts arguments which will be passed to the subtests
reference.
- name
-
diag $builder->name;
Returns the name of the current builder. Top level builders
default to $0 (the name of the executable).
Child builders are named via the
"child" method. If no name is
supplied, will be named "Child of
$parent->name".
- 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.
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 number 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 number of
tests.
- done_testing
-
$Test->done_testing();
$Test->done_testing($num_tests);
Declares that you are done testing, no more tests will be run
after this point.
If a plan has not yet been output, it will do so.
$num_tests is the number of tests you
planned to run. If a numbered plan was already declared, and if this
contradicts, a failing test will be run to reflect the planning mistake.
If "no_plan" was declared, this will
override.
If done_testing() is called twice, the
second call will issue a failing test.
If $num_tests is omitted, the number
of tests run will be used, like no_plan.
done_testing() is, in effect, used
when you'd want to use "no_plan", but
safer. You'd use it like so:
$Test->ok($a == $b);
$Test->done_testing();
Or to plan a variable number of tests:
for my $test (@tests) {
$Test->ok($test);
}
$Test->done_testing(scalar @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.
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.
"undef" only ever matches
another "undef".
- is_num
-
$Test->is_num($got, $expected, $name);
Like Test::More's is(). Checks if
"$got == $expected". This is the
numeric version.
"undef" only ever matches
another "undef".
- 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
-
$Test->like($thing, qr/$regex/, $name);
$Test->like($thing, '/$regex/', $name);
Like Test::More's like(). Checks if
$thing matches the given
$regex.
- unlike
-
$Test->unlike($thing, qr/$regex/, $name);
$Test->unlike($thing, '/$regex/', $name);
Like Test::More's unlike(). Checks if
$thing does not match the given
$regex.
- cmp_ok
-
$Test->cmp_ok($thing, $type, $that, $name);
Works just like Test::More's
cmp_ok().
$Test->cmp_ok($big_num, '!=', $other_big_num);
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";
These methods are useful when writing your own test methods.
- maybe_regex
-
$Test->maybe_regex(qr/$regex/);
$Test->maybe_regex('/$regex/');
This method used to be useful back when Test::Builder worked
on Perls before 5.6 which didn't have qr//. Now its pretty useless.
Convenience method for building testing functions that take
regular expressions as arguments.
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 its argument is not
recognized.
For example, a version of like(), sans
the useful diagnostic messages, could be written as:
sub laconic_like {
my ($self, $thing, $regex, $name) = @_;
my $usable_regex = $self->maybe_regex($regex);
die "expecting regex, found '$regex'\n"
unless $usable_regex;
$self->ok($thing =~ m/$usable_regex/, $name);
}
- is_fh
-
my $is_fh = $Test->is_fh($thing);
Determines if the given $thing can be
used as a filehandle.
- 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.
-
$Test->no_header($no_header);
If set to true, no "1..N" header will be
printed.
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 = $Test->explain(@msgs);
Will dump the contents of any references in a human readable
format. Handy for things like...
is_deeply($have, $want) || diag explain $have;
or
is_deeply($have, $want) || note explain $have;
- output
- failure_output
- todo_output
-
my $filehandle = $Test->output;
$Test->output($filehandle);
$Test->output($filename);
$Test->output(\$scalar);
These methods control where Test::Builder will print its
output. They take either an open $filehandle, a
$filename to open and write to or a
$scalar reference to append to. It will always
return a $filehandle.
output is where normal "ok/not ok" test
output goes.
Defaults to STDOUT.
failure_output is where diagnostic output on test
failures and diag() goes. It is normally not
read by Test::Harness and instead is displayed to the user.
Defaults to STDERR.
"todo_output" is used
instead of failure_output() for the diagnostics
of a failing TODO test. These will not be seen by the user.
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").
- no_log_results
- This will turn off result long-term storage. Calling this method will make
"details" and
"summary" useless. You may want to use
this if you are running enough tests to fill up all available memory.
Test::Builder->new->no_log_results();
There is no way to turn it back on.
- 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.
- is_passing
-
my $ok = $builder->is_passing;
Indicates if the test suite is currently passing.
More formally, it will be false if anything has happened which
makes it impossible for the test suite to pass. True otherwise.
For example, if no tests have run
is_passing() will be true because even though a
suite with no tests is a failure you can add a passing test to it and
start passing.
Don't think about it too much.
- 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 its 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 reason, 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().
Can also be used to set $TODO to a new
value while returning the old value:
my $old_reason = $Test->find_TODO($pack, 1, $new_reason);
- 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
figuring 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 highest context.
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 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 5.8.1 and later, Test::Builder is thread-safe. The test
number is shared by all threads. This means if one thread sets the test
number using current_test() they will all be
affected.
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.
You can directly disable thread support with one of the
following:
$ENV{T2_NO_IPC} = 1
or
no Test2::IPC;
or
Test2::API::test2_ipc_disable()
An informative hash, accessible via
details(), is stored for each test you perform. So
memory usage will scale linearly with each test run. Although this is not a
problem for most test suites, it can become an issue if you do large
(hundred thousands to million) combinatorics tests in the same run.
In such cases, you are advised to either split the test file into
smaller ones, or use a reverse approach, doing "normal" (code)
compares and triggering fail() should anything go
unexpected.
Future versions of Test::Builder will have a way to turn history
off.
CPAN can provide the best examples. Test::Simple, Test::More,
Test::Exception and Test::Differences all use Test::Builder.
Original code by chromatic, maintained by Michael G Schwern
<schwern@pobox.com>
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 <https://dev.perl.org/licenses/>
Visit the GSP FreeBSD Man Page Interface. Output converted with ManDoc.
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