Test::Builder::Tester(3p) Perl Programmers Reference Guide

Test::Builder::Tester(3p) Perl Programmers Reference Guide #

Test::Builder::Tester(3p) Perl Programmers Reference Guide

NNAAMMEE #

 Test::Builder::Tester - test testsuites that have been built with
 Test::Builder

SSYYNNOOPPSSIISS #

     use Test::Builder::Tester tests => 1;
     use Test::More;

     test_out("not ok 1 - foo");
     test_fail(+1);
     fail("foo");
     test_test("fail works");

DDEESSCCRRIIPPTTIIOONN #

 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.

FFuunnccttiioonnss 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.

BBUUGGSS #

 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>

AAUUTTHHOORR #

 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.

MMAAIINNTTAAIINNEERRSS #

 Chad Granum <exodist@cpan.org>

NNOOTTEESS #

 Thanks to Richard Clamp <richardc@unixbeard.net> for letting me use his
 testing system to try this module out on.

SSEEEE AALLSSOO #

 Test::Builder, Test::Builder::Tester::Color, Test::More.

perl v5.36.3 2023-02-15 Test::Builder::Tester(3p)