NAME Test::Tester - Ease testing test modules built with Test::Builder SYNOPSIS use Test::Tester tests => 5; use Test::MyStyle; check_test( sub { is_mystyle_eq("this", "that", "not eq"); }, { ok => 0, # expect this to fail name => "not eq", diag => "Expected: 'this'\nGot: 'that'", } ); or use Test::Tester; use Test::More tests => 2; use Test::MyStyle; my @results = run_tests( sub { is_database_alive("dbname"); }, { ok => 1, # expect the test to pass } ); # now use Test::More::like to check the diagnostic output like($result[1]->{diag}, "/^Database ping took \\d+ seconds$"/, "diag"); DESCRIPTION If you have written a test module based on Test::Builder then Test::Tester allows you to test it with the minimum of effort. HOW TO USE (THE EASY WAY) From version 0.08 Test::Tester no longer requires you to included anything special in your test modules. All you need to do is use Test::Tester; in your test script before any other Test::Builder based modules and away you go. Other modules based on Test::Builder can be used to help with the testing. In fact you can even use functions from your test module to test other functions from the same module - although that may not be a very wise thing to do! The easiest way to test is to do something like check_test( sub { is_mystyle_eq("this", "that", "not eq") }, { ok => 0, # we expect the test to fail name => "not eq", diag => "Expected: 'this'\nGot: 'that'", } ); this will execute the is_mystyle_eq test, capturing it's results and checking that they are what was expected. You may need to examine the test results in a more flexible way, for example, if the diagnostic output may be quite complex or it may involve something that you cannot predict in advance like a timestamp. In this case you can get direct access to the test results: my @results = run_tests( sub { is_database_alive("dbname"); }, { ok => 1, # expect the test to pass } ); like($result[1]->{diag}, "/^Database ping took \\d+ seconds$"/, "diag"); We cannot predict how long the database ping will take so we use Test::More's like() test to check that the diagnostic string is of the right form. HOW TO USE (THE HARD WAY) *This is here for backwards compatibility only* Make your module use the Test::Tester::Capture object instead of the Test::Builder one. How to do this depends on your module but assuming that your module holds the Test::Builder object in $Test and that all your test routines access it through $Test then providing a function something like this sub set_builder { $Test = shift; } should allow your test scripts to do Test::YourModule::set_builder(Test::Tester->capture); and after that any tests inside your module will captured. TEST RESULTS The result of each test is captured in a hash. These hashes are the same as the hashes returned by Test::Builder->details but with a couple of extra fields. These fields are documented in Test::Builder in the details() function ok Did the test pass? actual_ok Did the test really pass? That is, did the pass come from Test::Builder->ok() or did it pass because it was a TODO test? name The name supplied for the test. type What kind of test? Possibilities include, skip, todo etc. See Test::Builder for more details. reason The reason for the skip, todo etc. See Test::Builder for more details. These fields are exclusive to Test::Tester. diag Any diagnostics that were output for the test. This only includes diagnostics output after the test result is declared. depth This allows you to check that your test module is setting the correct value for $Test::Builder::Level and thus giving the correct file and line number when a test fails. It is calculated by looking at caller() and $Test::Builder::Level. It should count how many subroutines there are before jumping into the function you are testing so for example in run_tests( sub { my_test_function("a", "b") } ); the depth should be 1 and in sub deeper { my_test_function("a", "b") } run_tests(sub { deeper() }); depth should be 2, that is 1 for the sub {} and one for deeper(). This might seem a little complex but unless you are calling your test functions inside subroutines or evals then depth will always be 1. Note: depth will not be correctly calculated for tests that run from a signal handler or an END block or anywhere else that hides the call stack. Some of the Test::Testers functions return arrays of these hashes, just like Test::Builder->details. That is, the hash for the first test will be array element 1 (not 0). Element 0 will not be a hash it will be a string which contains any diagnostic output that came before the first test. This should usually be empty. EXPORTED FUNCTIONS ($prem, @results) = run_tests(\&test_sub, $name) \&test_sub is a reference to a subroutine. $name is a string. run_tests runs the subroutine in $test_sub and captures the results of any tests inside it. You can run more than 1 test inside this subroutine if you like. $prem is a string containg any diagnostic output from before the first test. @results is an array of test result hashes. cmp_result(\%result, \%expect, $name) \%result is a ref to a test result hash. \%expect is a ref to a hash of expected values for the test result. cmp_result compares the result with the expected values. If any differences are found it outputs diagnostics. You may leave out any field from the expected result and cmp_result will not do the comparison of that field. cmp_results(\@results, \@expects, $name) \@results is a ref to an array of test results. \@expects is a ref to an array of hash refs. cmp_results checks that the results match the expected results and if any differences are found it outputs diagnostics. It first checks that the number of elements in \@results and \@expects is the same. Then it goes through each result checking it against the expected result as in cmp_result() above. ($prem, @results) = check_tests(\&test_sub, \@expects, $name) \&test_sub is a reference to a subroutine. \@expect is a ref to an array of hash refs which are expected test results. check_tests combines run_tests and cmp_tests into a single call. It also checks if the tests died at any stage. It returns the same values as run_tests, so you can further examine the test results if you need to. ($prem, @results) = check_test(\&test_sub, \%expect, $name) \&test_sub is a reference to a subroutine. \%expect is a ref to an hash of expected values for the test result. check_test is a wrapper around check_tests. It combines run_tests and cmp_tests into a single call, checking if the test died. It assumes that only a single test is run inside \&test_sub and test to make this is true. It returns the same values as run_tests, so you can further examine the test results if you need to. HOW IT WORKS Normally, a test module (let's call it Test:MyStyle) calls Test::Builder->new to get the Test::Builder object. Test::MyStyle calls methods on this object to record information about test results. When Test::Tester is loaded, it replaces Test::Builder's new() method with one which returns a Test::Tester::Delegate object. Most of the time this object appears to be the real Test::Builder object. Any methods that are called are delegated to the real Test::Builder object so everything works perfectly. However once we go into test mode, the method calls are no longer passed to the real Test::Builder object, instead they go to the Test::Tester::Capture object. This object seems exactly like the real Test::Builder object, except, instead of outputting test results and diagnostics, it just records all the information for later analysis. SEE ALSO Test::Builder the source of testing goodness. Test::Builder::Tester for an alternative approach to the problem tackled by Test::Tester - captures the strings output by Test::Builder. This means you cannot get separate access to the individual pieces of information and you must predict exactly what your test will output. AUTHOR This module is copyright 2004 Fergal Daly , some parts are based on other people's work. Plan handling lifted from Test::More. written by Michael G Schwern . Test::Tester::Capture is a cut down and hacked up version of Test::Builder. Test::Builder was written by chromatic and Michael G Schwern . LICENSE Under the same license as Perl itself See http://www.perl.com/perl/misc/Artistic.html