Test::Output(3) User Contributed Perl Documentation 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. o :stdout - the subs with "stdout" in the name. o :stderr - the subs with "stderr" in the name. o :functions - the subs with "_from" at the end. o :output - the subs with "output" in the name. o :combined - the subs with "combined" in the name. o :tests - everything that outputs TAP o :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, "bdfoy@cpan.org". Shawn Sorichetti, "" 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 . 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. perl v5.38.0 2023-07-28 Test::Output(3)