Test::Builder::Tester(3pm) Perl Programmers Reference Guide Test::Builder::Tester(3pm)
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 debug-ging) debugging)
ging) to the normal output.
Methods
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 once all further
output from Test::Builder will be captured by Test::Builder::Tester. This means that your 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 has changed between Test::Builder ver-sions, versions,
sions, 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 method 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 convience 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 that that 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 convience, 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 methods 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 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, if you have the Term::ANSIColor module installed (which you should do by default
from perl 5.005 onwards), "test_test" can colour the background of the debug information to dis-ambiguate disambiguate
ambiguate the different types of output. The debug output will have it's 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
Calls Test::Builder's "no_ending" method 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 installed and is compatible with your ter-minal. terminal.
minal.
Bugs (and requests for new features) can be reported to the author though the CPAN RT system:
<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Test-Builder-Tester
AUTHOR
Copyright Mark Fowler <mark@twoshortplanks.com> 2002, 2004.
Some code taken from Test::More and Test::Catch, written by 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.
NOTES
This code has been tested explicitly on the following versions of perl: 5.7.3, 5.6.1, 5.6.0,
5.005_03, 5.004_05 and 5.004.
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 v5.8.8 2001-09-21 Test::Builder::Tester(3pm)
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