phpMan > man > Test::Tester

NAME
    Test::Tester - Ease testing test modules built with Test::Builder

SYNOPSIS
      use Test::Tester tests => 6;

      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 tests => 6;

      use Test::MyStyle;

      check_test(
        sub {
          is_mystyle_qr("this", "that", "not matching");
        },
        {
          ok => 0, # expect this to fail
          name => "not matching",
          diag => qr/Expected: 'this'\s+Got: 'that'/,
        }
      );

    or

      use Test::Tester;

      use Test::More tests => 3;
      use Test::MyStyle;

      my ($premature, @results) = run_tests(
        sub {
          is_database_alive("dbname");
        }
      );

      # now use Test::More::like to check the diagnostic output

      like($results[0]->{diag}, "/^Database ping took \\d+ seconds$"/, "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 module to test other functions from the same module (while this is
    possible it is probably not a good idea, if your module has bugs, then using it to test itself
    may give the wrong answers).

    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 its results and checking that they are what
    was expected.

    You may need to examine the test results in a more flexible way, for example, the diagnostic
    output may be quite long or 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 ($premature, @results) = run_tests(
        sub {
          is_database_alive("dbname");
        }
      );

      like($result[0]->{diag}, "/^Database ping took \\d+ seconds$"/, "diag");

    or

      check_test(
        sub { is_mystyle_qr("this", "that", "not matching") },
        {
          ok => 0, # we expect the test to fail
          name => "not matching",
          diag => qr/Expected: 'this'\s+Got: 'that'/,
        }
      );

    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.

      Note that Test::Builder ensures that any diagnostics end in a \n and it in earlier versions of
      Test::Tester it was essential that you have the final \n in your expected diagnostics. From
      version 0.10 onward, Test::Tester will add the \n if you forgot it. It will not add a \n if
      you are expecting no diagnostics. See below for help tracking down hard to find space and tab
      related problems.

    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 if your tests look like the simple examples in this doc then you don't need to
      worry as the depth will always be 1 and that's what Test::Tester expects by default.

      Note: if you do not specify a value for depth in check_test() then it automatically compares
      it against 1, if you really want to skip the depth test then pass in undef.

      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 Test::Tester's 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, if it's not, it means something output
    diagnostics before any test results showed up.

SPACES AND TABS
    Appearances can be deceptive, especially when it comes to emptiness. If you are scratching your
    head trying to work out why Test::Tester is saying that your diagnostics are wrong when they
    look perfectly right then the answer is probably whitespace. From version 0.10 on, Test::Tester
    surrounds the expected and got diag values with single quotes to make it easier to spot trailing
    whitespace. So in this example

      # Got diag (5 bytes):
      # 'abcd '
      # Expected diag (4 bytes):
      # 'abcd'

    it is quite clear that there is a space at the end of the first string. Another way to solve
    this problem is to use colour and inverse video on an ANSI terminal, see below COLOUR below if
    you want this.

    Unfortunately this is sometimes not enough, neither colour nor quotes will help you with
    problems involving tabs, other non-printing characters and certain kinds of problems inherent in
    Unicode. To deal with this, you can switch Test::Tester into a mode whereby all "tricky"
    characters are shown as \{xx}. Tricky characters are those with ASCII code less than 33 or
    higher than 126. This makes the output more difficult to read but much easier to find subtle
    differences between strings. To turn on this mode either call "show_space()" in your test script
    or set the "TESTTESTERSPACE" environment variable to be a true value. The example above would
    then look like

      # Got diag (5 bytes):
      # abcd\x{20}
      # Expected diag (4 bytes):
      # abcd

COLOUR
    If you prefer to use colour as a means of finding tricky whitespace characters then you can set
    the "TESTTESTCOLOUR" environment variable to a comma separated pair of colours, the first for
    the foreground, the second for the background. For example "white,red" will print white text on
    a red background. This requires the Term::ANSIColor module. You can specify any colour that
    would be acceptable to the Term::ANSIColor::color function.

    If you spell colour differently, that's no problem. The "TESTTESTERCOLOR" variable also works
    (if both are set then the British spelling wins out).

EXPORTED FUNCTIONS
   ($premature, @results) = run_tests(\&test_sub)
    \&test_sub is a reference to a subroutine.

    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.

    $premature is a string containing 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.

   ($premature, @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.

   ($premature, @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
    include a test to make sure this is true.

    It returns the same values as run_tests, so you can further examine the test results if you need
    to.

   show_space()
    Turn on the escaping of characters as described in the SPACES AND TABS section.

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 behaves as 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.

CAVEATS
    Support for calling Test::Builder->note is minimal. It's implemented as an empty stub, so
    modules that use it will not crash but the calls are not recorded for testing purposes like the
    others. Patches welcome.

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 2005 Fergal Daly <fergal AT esatclear.ie>, some parts are based on other
    people's work.

    Plan handling lifted from Test::More. written by Michael G Schwern <schwern AT pobox.com>.

    Test::Tester::Capture is a cut down and hacked up version of Test::Builder. Test::Builder was
    written by chromatic <chromatic AT wgz.org> and Michael G Schwern <schwern AT pobox.com>.

LICENSE
    Under the same license as Perl itself

    See http://www.perl.com/perl/misc/Artistic.html