Test::Output(3)

NAME
Test::Output - Utilities to test STDOUT and STDERR messages.

SYNOPSIS
    use Test::More tests => 4;
    use Test::Output;

    sub writer {
      print "Write out.\n";
      print STDERR "Error out.\n";
    }

    stdout_is(\&writer,"Write out.\n",'Test STDOUT');

    stderr_isnt(\&writer,"No error out.\n",'Test STDERR');

    combined_is(
                \&writer,
                "Write out.\nError out.\n",
                'Test STDOUT & STDERR combined'
               );

    output_is(
              \&writer,
              "Write out.\n",
              "Error out.\n",
              'Test STDOUT & STDERR'
            );

   # Use bare blocks.

   stdout_is { print "test" } "test", "Test STDOUT";
   stderr_isnt { print "bad test" } "test", "Test STDERR";
   output_is { print 'STDOUT'; print STDERR 'STDERR' }
     "STDOUT", "STDERR", "Test output";

DESCRIPTION
Test::Output provides a simple interface for testing output sent to "STDOUT" or "STDERR". A number of different utilities are included to try and be as flexible as possible to the tester.

Likewise, Capture::Tiny provides a much more robust capture mechanism without than the original Test::Output::Tie.

TESTS

  STDOUT

stdout_is
stdout_isnt
       stdout_is  ( $coderef, $expected, 'description' );
       stdout_is    { ... } $expected, 'description';
       stdout_isnt( $coderef, $expected, 'description' );
       stdout_isnt  { ... } $expected, 'description';

    stdout_is() captures output sent to "STDOUT" from $coderef and compares it against $expected. The test passes if equal.

    stdout_isnt() passes if "STDOUT" is not equal to $expected.

stdout_like
stdout_unlike
       stdout_like  ( $coderef, qr/$expected/, 'description' );
       stdout_like    { ... } qr/$expected/, 'description';
       stdout_unlike( $coderef, qr/$expected/, 'description' );
       stdout_unlike  { ... } qr/$expected/, 'description';

    stdout_like() captures the output sent to "STDOUT" from $coderef and compares it to the regex in $expected. The test passes if the regex matches.

    stdout_unlike() passes if STDOUT does not match the regex.

  STDERR

stderr_is
stderr_isnt
       stderr_is  ( $coderef, $expected, 'description' );
       stderr_is    {... } $expected, 'description';

       stderr_isnt( $coderef, $expected, 'description' );
       stderr_isnt  {... } $expected, 'description';

    stderr_is() is similar to "stdout_is", except that it captures "STDERR". The test passes if "STDERR" from $coderef equals $expected.

    stderr_isnt() passes if "STDERR" is not equal to $expected.

stderr_like
stderr_unlike
       stderr_like  ( $coderef, qr/$expected/, 'description' );
       stderr_like   { ...} qr/$expected/, 'description';
       stderr_unlike( $coderef, qr/$expected/, 'description' );
       stderr_unlike  { ...} qr/$expected/, 'description';

    stderr_like() is similar to stdout_like() except that it compares the regex $expected to "STDERR" captured from $codref. The test passes if the regex matches.

    stderr_unlike() passes if "STDERR" does not match the regex.

  COMBINED OUTPUT

combined_is
combined_isnt
       combined_is   ( $coderef, $expected, 'description' );
       combined_is   {... } $expected, 'description';
       combined_isnt ( $coderef, $expected, 'description' );
       combined_isnt {... } $expected, 'description';

    combined_is() directs "STDERR" to "STDOUT" then captures "STDOUT". This is equivalent to UNIXs "2>&1". The test passes if the combined "STDOUT" and "STDERR" from $coderef equals $expected.

    combined_isnt() passes if combined "STDOUT" and "STDERR" are not equal to $expected.

combined_like
combined_unlike
       combined_like   ( $coderef, qr/$expected/, 'description' );
       combined_like   { ...} qr/$expected/, 'description';
       combined_unlike ( $coderef, qr/$expected/, 'description' );
       combined_unlike { ...} qr/$expected/, 'description';

    combined_like() is similar to combined_is() except that it compares a regex ("$expected)" to "STDOUT" and "STDERR" captured from $codref. The test passes if the regex matches.

    combined_unlike() passes if the combined "STDOUT" and "STDERR" does not match the regex.

  OUTPUT

output_is
output_isnt
       output_is  ( $coderef, $expected_stdout, $expected_stderr, 'description' );
       output_is    {... } $expected_stdout, $expected_stderr, 'description';
       output_isnt( $coderef, $expected_stdout, $expected_stderr, 'description' );
       output_isnt  {... } $expected_stdout, $expected_stderr, 'description';

    The output_is() function is a combination of the stdout_is() and stderr_is() functions. For example:

      output_is(sub {print "foo"; print STDERR "bar";},'foo','bar');

    is functionally equivalent to

      stdout_is(sub {print "foo";},'foo')
        && stderr_is(sub {print STDERR "bar";},'bar');

    except that $coderef is only executed once.

    Unlike stdout_is() and stderr_is() which ignore STDERR and STDOUT respectively, output_is() requires both "STDOUT" and "STDERR" to match in order to pass. Setting either $expected_stdout or $expected_stderr to "undef" ignores "STDOUT" or "STDERR" respectively.

      output_is(sub {print "foo"; print STDERR "bar";},'foo',undef);

    is the same as

      stdout_is(sub {print "foo";},'foo')

    output_isnt() provides the opposite function of output_is(). It is a combination of stdout_isnt() and stderr_isnt().

      output_isnt(sub {print "foo"; print STDERR "bar";},'bar','foo');

    is functionally equivalent to

      stdout_isnt(sub {print "foo";},'bar')
        && stderr_isnt(sub {print STDERR "bar";},'foo');

    As with output_is(), setting either $expected_stdout or $expected_stderr to "undef" ignores the output to that facility.

      output_isnt(sub {print "foo"; print STDERR "bar";},undef,'foo');

    is the same as

      stderr_is(sub {print STDERR "bar";},'foo')

output_like
output_unlike
      output_like  ( $coderef, $regex_stdout, $regex_stderr, 'description' );
      output_like  { ... } $regex_stdout, $regex_stderr, 'description';
      output_unlike( $coderef, $regex_stdout, $regex_stderr, 'description' );
      output_unlike { ... } $regex_stdout, $regex_stderr, 'description';

    output_like() and output_unlike() follow the same principles as output_is() and output_isnt() except they use a regular expression for matching.

    output_like() attempts to match $regex_stdout and $regex_stderr against "STDOUT" and "STDERR" produced by $coderef. The test passes if both match.

      output_like(sub {print "foo"; print STDERR "bar";},qr/foo/,qr/bar/);

    The above test is successful.

    Like output_is(), setting either $regex_stdout or $regex_stderr to "undef" ignores the output to that facility.

      output_like(sub {print "foo"; print STDERR "bar";},qr/foo/,undef);

    is the same as

      stdout_like(sub {print "foo"; print STDERR "bar";},qr/foo/);

    output_unlike() test pass if output from $coderef doesn't match $regex_stdout and $regex_stderr.

EXPORTS
By default, all subroutines are exported by default.

•   :stdout - the subs with "stdout" in the name.

•   :stderr - the subs with "stderr" in the name.

•   :functions - the subs with "_from" at the end.

•   :output - the subs with "output" in the name.

•   :combined - the subs with "combined" in the name.

•   :tests - everything that outputs TAP

•   :all - everything (which is the same as the default)

FUNCTIONS

  stdout_from
  my $stdout = stdout_from($coderef)
  my $stdout = stdout_from { ... };

stdout_from() executes $coderef and captures STDOUT.

  stderr_from
  my $stderr = stderr_from($coderef)
  my $stderr = stderr_from { ... };

stderr_from() executes $coderef and captures "STDERR".

  output_from
  my ($stdout, $stderr) = output_from($coderef)
  my ($stdout, $stderr) = output_from {...};

output_from() executes $coderef one time capturing both "STDOUT" and "STDERR".

  combined_from
  my $combined = combined_from($coderef);
  my $combined = combined_from {...};

combined_from() executes $coderef one time combines "STDOUT" and "STDERR", and captures them. combined_from() is equivalent to using "2>&1" in UNIX.

AUTHOR
Currently maintained by brian d foy, "briandfoy@pobox.com".

Shawn Sorichetti, "<ssoriche@cpan.org>"

SOURCE AVAILABILITY
This module is in Github:

        http://github.com/briandfoy/test-output

BUGS
Please report any bugs or feature requests to "bug-test-output@rt.cpan.org", or through the web interface at <http://rt.cpan.org>. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

ACKNOWLEDGEMENTS
Thanks to chromatic whose TieOut.pm was the basis for capturing output.

Also thanks to rjbs for his help cleaning the documentation, and pushing me to Sub::Exporter. (This feature has been removed since it uses none of Sub::Exporter's strengths).

Thanks to David Wheeler for providing code block support and tests.

Thanks to Michael G Schwern for the solution to combining "STDOUT" and "STDERR".

COPYRIGHT & LICENSE
Copyright 2005-2021 Shawn Sorichetti, All Rights Reserved.

This module is licensed under the Artistic License 2.0.