Provided by: perl-doc_5.38.2-3.2ubuntu0.1_all 
NAME
Test::Builder::Tester - test testsuites that have been built with Test::Builder
SYNOPSIS
use Test::Builder::Tester tests => 1;
use Test::More;
test_out("not ok 1 - foo");
test_fail(+1);
fail("foo");
test_test("fail works");
DESCRIPTION
A module that helps you test testing modules that are built with Test::Builder.
The testing system is designed to be used by performing a three step process for each test you wish to
test. This process starts with using "test_out" and "test_err" in advance to declare what the testsuite
you are testing will output with Test::Builder to stdout and stderr.
You then can run the test(s) from your test suite that call Test::Builder. At this point the output of
Test::Builder is safely captured by Test::Builder::Tester rather than being interpreted as real test
output.
The final stage is to call "test_test" that will simply compare what you predeclared to what
Test::Builder actually outputted, and report the results back with a "ok" or "not ok" (with debugging) to
the normal output.
Functions
These are the six methods that are exported as default.
test_out
test_err
Procedures for predeclaring the output that your test suite is expected to produce until "test_test"
is called. These procedures automatically assume that each line terminates with "\n". So
test_out("ok 1","ok 2");
is the same as
test_out("ok 1\nok 2");
which is even the same as
test_out("ok 1");
test_out("ok 2");
Once "test_out" or "test_err" (or "test_fail" or "test_diag") have been called, all further output
from Test::Builder will be captured by Test::Builder::Tester. This means that you will not be able
perform further tests to the normal output in the normal way until you call "test_test" (well, unless
you manually meddle with the output filehandles)
test_fail
Because the standard failure message that Test::Builder produces whenever a test fails will be a
common occurrence in your test error output, and because it has changed between Test::Builder
versions, rather than forcing you to call "test_err" with the string all the time like so
test_err("# Failed test ($0 at line ".line_num(+1).")");
"test_fail" exists as a convenience function that can be called instead. It takes one argument, the
offset from the current line that the line that causes the fail is on.
test_fail(+1);
This means that the example in the synopsis could be rewritten more simply as:
test_out("not ok 1 - foo");
test_fail(+1);
fail("foo");
test_test("fail works");
test_diag
As most of the remaining expected output to the error stream will be created by Test::Builder's
"diag" function, Test::Builder::Tester provides a convenience function "test_diag" that you can use
instead of "test_err".
The "test_diag" function prepends comment hashes and spacing to the start and newlines to the end of
the expected output passed to it and adds it to the list of expected error output. So, instead of
writing
test_err("# Couldn't open file");
you can write
test_diag("Couldn't open file");
Remember that Test::Builder's diag function will not add newlines to the end of output and test_diag
will. So to check
Test::Builder->new->diag("foo\n","bar\n");
You would do
test_diag("foo","bar")
without the newlines.
test_test
Actually performs the output check testing the tests, comparing the data (with "eq") that we have
captured from Test::Builder against what was declared with "test_out" and "test_err".
This takes name/value pairs that effect how the test is run.
title (synonym 'name', 'label')
The name of the test that will be displayed after the "ok" or "not ok".
skip_out
Setting this to a true value will cause the test to ignore if the output sent by the test to the
output stream does not match that declared with "test_out".
skip_err
Setting this to a true value will cause the test to ignore if the output sent by the test to the
error stream does not match that declared with "test_err".
As a convenience, if only one argument is passed then this argument is assumed to be the name of the
test (as in the above examples.)
Once "test_test" has been run test output will be redirected back to the original filehandles that
Test::Builder was connected to (probably STDOUT and STDERR,) meaning any further tests you run will
function normally and cause success/errors for Test::Harness.
line_num
A utility function that returns the line number that the function was called on. You can pass it an
offset which will be added to the result. This is very useful for working out the correct text of
diagnostic functions that contain line numbers.
Essentially this is the same as the "__LINE__" macro, but the line_num(+3) idiom is arguably nicer.
In addition to the six exported functions there exists one function that can only be accessed with a
fully qualified function call.
color
When "test_test" is called and the output that your tests generate does not match that which you
declared, "test_test" will print out debug information showing the two conflicting versions. As this
output itself is debug information it can be confusing which part of the output is from "test_test"
and which was the original output from your original tests. Also, it may be hard to spot things like
extraneous whitespace at the end of lines that may cause your test to fail even though the output
looks similar.
To assist you "test_test" can colour the background of the debug information to disambiguate the
different types of output. The debug output will have its background coloured green and red. The
green part represents the text which is the same between the executed and actual output, the red
shows which part differs.
The "color" function determines if colouring should occur or not. Passing it a true or false value
will enable or disable colouring respectively, and the function called with no argument will return
the current setting.
To enable colouring from the command line, you can use the Text::Builder::Tester::Color module like
so:
perl -Mlib=Text::Builder::Tester::Color test.t
Or by including the Test::Builder::Tester::Color module directly in the PERL5LIB.
BUGS
Test::Builder::Tester does not handle plans well. It has never done anything special with plans. This
means that plans from outside Test::Builder::Tester will effect Test::Builder::Tester, worse plans when
using Test::Builder::Tester will effect overall testing. At this point there are no plans to fix this bug
as people have come to depend on it, and Test::Builder::Tester is now discouraged in favor of
Test2::API::intercept(). See <https://github.com/Test-More/test-more/issues/667>
Calls "Test::Builder->no_ending" turning off the ending tests. This is needed as otherwise it will trip
out because we've run more tests than we strictly should have and it'll register any failures we had that
we were testing for as real failures.
The color function doesn't work unless Term::ANSIColor is compatible with your terminal. Additionally,
Win32::Console::ANSI must be installed on windows platforms for color output.
Bugs (and requests for new features) can be reported to the author though GitHub:
<https://github.com/Test-More/test-more/issues>
AUTHOR
Copyright Mark Fowler <mark@twoshortplanks.com> 2002, 2004.
Some code taken from Test::More and Test::Catch, written by Michael G Schwern <schwern@pobox.com>.
Hence, those parts Copyright Micheal G Schwern 2001. Used and distributed with permission.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl
itself.
MAINTAINERS
Chad Granum <exodist@cpan.org>
NOTES
Thanks to Richard Clamp <richardc@unixbeard.net> for letting me use his testing system to try this module
out on.
SEE ALSO
Test::Builder, Test::Builder::Tester::Color, Test::More.
perl v5.38.2 2025-04-08 Test::Builder::Tester(3perl)