Test::Builder::Tester - test testsuites that have been built with Test::Builder
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.
These are the six methods that are exported as default.
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)
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 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 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");
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.
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.
The name of the test that will be displayed after the ok
or not
ok
.
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
.
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.
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.
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 disambiguate 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.
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 terminal.
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
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.
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.