Test::Harness(3)

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Test::Harness(3)
NAME
Test::Harness - Run Perl standard test scripts with statistics

VERSION
Version 2.42;

$Header: /home/cvs/test-harness/lib/Test/Harness.pm,v 1.85 2004/04/29 03:13:43 andy Exp $

SYNOPSIS
use Test::Harness;

runtests(@test_files);

DESCRIPTION
STOP! If all you want to do is write a test script, consider using
Test::Simple. Otherwise, read on.

(By using the Test module, you can write test scripts without knowing the
exact output this module expects. However, if you need to know the
specifics, read on!)

Perl test scripts print to standard output "ok N" for each single test,
where "N" is an increasing sequence of integers. The first line output by a
standard test script is "1..M" with "M" being the number of tests that
should be run within the test script. Test::Harness::runtests(@tests) runs
all the testscripts named as arguments and checks standard output for the
expected "ok N" strings.

After all tests have been performed, runtests() prints some performance
statistics that are computed by the Benchmark module.

The test script output

The following explains how Test::Harness interprets the output of your test
program.

'1..M'
This header tells how many tests there will be. For example, 1..10
means you plan on running 10 tests. This is a safeguard in case your
test dies quietly in the middle of its run.

It should be the first non-comment line output by your test program.

In certain instances, you may not know how many tests you will
ultimately be running. In this case, it is permitted for the 1..M
header to appear as the last line output by your test (again, it can be
followed by further comments).

Under no circumstances should 1..M appear in the middle of your output
or more than once.

'ok', 'not ok'. Ok?
Any output from the testscript to standard error is ignored and
bypassed, thus will be seen by the user. Lines written to standard
output containing "/^(not\s+)?ok\b/" are interpreted as feedback for
runtests(). All other lines are discarded.

"/^not ok/" indicates a failed test. "/^ok/" is a successful test.

test numbers
Perl normally expects the 'ok' or 'not ok' to be followed by a test
number. It is tolerated if the test numbers after 'ok' are omitted. In
this case Test::Harness maintains temporarily its own counter until the
script supplies test numbers again. So the following test script

print <<END;
1..6
not ok
ok
not ok
ok
ok
END

will generate

FAILED tests 1, 3, 6
Failed 3/6 tests, 50.00% okay

test names
Anything after the test number but before the # is considered to be the
name of the test.

ok 42 this is the name of the test

Currently, Test::Harness does nothing with this information.

Skipping tests
If the standard output line contains the substring " # Skip" (with
variations in spacing and case) after "ok" or "ok NUMBER", it is
counted as a skipped test. If the whole testscript succeeds, the count
of skipped tests is included in the generated output. "Test::Harness"
reports the text after " # Skip\S*\s+" as a reason for skipping.

ok 23 # skip Insufficient flogiston pressure.

Similarly, one can include a similar explanation in a 1..0 line emitted
if the test script is skipped completely:

1..0 # Skipped: no leverage found

Todo tests
If the standard output line contains the substring " # TODO " after
"not ok" or "not ok NUMBER", it is counted as a todo test. The text
afterwards is the thing that has to be done before this test will
succeed.

not ok 13 # TODO harness the power of the atom

Note that the TODO must have a space after it.

These tests represent a feature to be implemented or a bug to be fixed
and act as something of an executable "thing to do" list. They are not
expected to succeed. Should a todo test begin succeeding,
Test::Harness will report it as a bonus. This indicates that whatever
you were supposed to do has been done and you should promote this to a
normal test.

Bail out!
As an emergency measure, a test script can decide that further tests
are useless (e.g. missing dependencies) and testing should stop
immediately. In that case the test script prints the magic words

Bail out!

to standard output. Any message after these words will be displayed by
"Test::Harness" as the reason why testing is stopped.

Comments
Additional comments may be put into the testing output on their own
lines. Comment lines should begin with a '#', Test::Harness will
ignore them.

ok 1
# Life is good, the sun is shining, RAM is cheap.
not ok 2
# got 'Bush' expected 'Gore'

Anything else
Any other output Test::Harness sees it will silently ignore BUT WE PLAN
TO CHANGE THIS! If you wish to place additional output in your test
script, please use a comment.

Taint mode

Test::Harness will honor the "-T" or "-t" in the #! line on your test
files. So if you begin a test with:

#!perl -T

the test will be run with taint mode on.

Configuration variables.

These variables can be used to configure the behavior of Test::Harness.
They are exported on request.

$Test::Harness::Verbose
The global variable $Test::Harness::Verbose is exportable and can be
used to let "runtests()" display the standard output of the script
without altering the behavior otherwise. The prove utility's "-v" flag
will set this.

$Test::Harness::switches
The global variable $Test::Harness::switches is exportable and can be
used to set perl command line options used for running the test
script(s). The default value is "-w". It overrides "HARNESS_SWITCHES".

Failure

It will happen: your tests will fail. After you mop up your ego, you can
begin examining the summary report:

t/base..............ok
t/nonumbers.........ok
t/ok................ok
t/test-harness......ok
t/waterloo..........dubious
Test returned status 3 (wstat 768, 0x300)
DIED. FAILED tests 1, 3, 5, 7, 9, 11, 13, 15, 17, 19
Failed 10/20 tests, 50.00% okay
Failed Test Stat Wstat Total Fail Failed List of Failed
-----------------------------------------------------------------------
t/waterloo.t 3 768 20 10 50.00% 1 3 5 7 9 11 13 15 17 19
Failed 1/5 test scripts, 80.00% okay. 10/44 subtests failed, 77.27% okay.

Everything passed but t/waterloo.t. It failed 10 of 20 tests and exited
with non-zero status indicating something dubious happened.

The columns in the summary report mean:

Failed Test
The test file which failed.

Stat
If the test exited with non-zero, this is its exit status.

Wstat
The wait status of the test.

Total
Total number of tests expected to run.

Fail
Number which failed, either from "not ok" or because they never ran.

Failed
Percentage of the total tests which failed.

List of Failed
A list of the tests which failed. Successive failures may be
abbreviated (ie. 15-20 to indicate that tests 15, 16, 17, 18, 19 and 20
failed).

Functions

Test::Harness currently only has one function, here it is.

runtests
my $allok = runtests(@test_files);

This runs all the given @test_files and divines whether they passed or
failed based on their output to STDOUT (details above). It prints out
each individual test which failed along with a summary report and a how
long it all took.

It returns true if everything was ok. Otherwise it will die() with one
of the messages in the DIAGNOSTICS section.

This is just _run_all_tests() plus _show_results()

EXPORT
&runtests is exported by Test::Harness by default.

$verbose, $switches and $debug are exported upon request.

DIAGNOSTICS
"All tests successful.\nFiles=%d, Tests=%d, %s"
If all tests are successful some statistics about the performance are
printed.

"FAILED tests %s\n\tFailed %d/%d tests, %.2f%% okay."
For any single script that has failing subtests statistics like the
above are printed.

"Test returned status %d (wstat %d)"
Scripts that return a non-zero exit status, both "$? >> 8" and $? are
printed in a message similar to the above.

"Failed 1 test, %.2f%% okay. %s"
"Failed %d/%d tests, %.2f%% okay. %s"
If not all tests were successful, the script dies with one of the above
messages.

"FAILED--Further testing stopped: %s"
If a single subtest decides that further testing will not make sense,
the script dies with this message.

ENVIRONMENT
"HARNESS_ACTIVE"
Harness sets this before executing the individual tests. This allows
the tests to determine if they are being executed through the harness
or by any other means.

"HARNESS_COLUMNS"
This value will be used for the width of the terminal. If it is not set
then it will default to "COLUMNS". If this is not set, it will default
to 80. Note that users of Bourne-sh based shells will need to "export
COLUMNS" for this module to use that variable.

"HARNESS_COMPILE_TEST"
When true it will make harness attempt to compile the test using
"perlcc" before running it.

NOTE This currently only works when sitting in the perl source
directory!

"HARNESS_DEBUG"
If true, Test::Harness will print debugging information about itself as
it runs the tests. This is different from "HARNESS_VERBOSE", which
prints the output from the test being run. Setting
$Test::Harness::Debug will override this, or you can use the "-d"
switch in the prove utility.

"HARNESS_FILELEAK_IN_DIR"
When set to the name of a directory, harness will check after each test
whether new files appeared in that directory, and report them as

LEAKED FILES: scr.tmp 0 my.db

If relative, directory name is with respect to the current directory at
the moment runtests() was called. Putting absolute path into
"HARNESS_FILELEAK_IN_DIR" may give more predictable results.

"HARNESS_IGNORE_EXITCODE"
Makes harness ignore the exit status of child processes when defined.

"HARNESS_NOTTY"
When set to a true value, forces it to behave as though STDOUT were not
a console. You may need to set this if you don't want harness to
output more frequent progress messages using carriage returns. Some
consoles may not handle carriage returns properly (which results in a
somewhat messy output).

"HARNESS_OK_SLOW"
If true, the "ok" messages are printed out only every second. This
reduces output and may help increase testing speed over slow
connections, or with very large numbers of tests.

"HARNESS_PERL"
Usually your tests will be run by $^X, the currently-executing Perl.
However, you may want to have it run by a different executable, such as
a threading perl, or a different version.

If you're using the prove utility, you can use the "--perl" switch.

"HARNESS_PERL_SWITCHES"
Its value will be prepended to the switches used to invoke perl on each
test. For example, setting "HARNESS_PERL_SWITCHES" to "-W" will run
all tests with all warnings enabled.

"HARNESS_VERBOSE"
If true, Test::Harness will output the verbose results of running its
tests. Setting $Test::Harness::verbose will override this, or you can
use the "-v" switch in the prove utility.

EXAMPLE
Here's how Test::Harness tests itself

$ cd ~/src/devel/Test-Harness
$ perl -Mblib -e 'use Test::Harness qw(&runtests $verbose);
$verbose=0; runtests @ARGV;' t/*.t
Using /home/schwern/src/devel/Test-Harness/blib
t/base..............ok
t/nonumbers.........ok
t/ok................ok
t/test-harness......ok
All tests successful.
Files=4, Tests=24, 2 wallclock secs ( 0.61 cusr + 0.41 csys = 1.02 CPU)

SEE ALSO
The included prove utility for running test scripts from the command line,
Test and Test::Simple for writing test scripts, Benchmark for the
underlying timing routines, Devel::CoreStack to generate core dumps from
failed tests and Devel::Cover for test coverage analysis.

AUTHORS
Either Tim Bunce or Andreas Koenig, we don't know. What we know for sure
is, that it was inspired by Larry Wall's TEST script that came with perl
distributions for ages. Numerous anonymous contributors exist. Andreas
Koenig held the torch for many years, and then Michael G Schwern.

Current maintainer is Andy Lester "<andy@petdance.com>".

LICENSE
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.

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

TODO
Provide a way of running tests quietly (ie. no printing) for automated
validation of tests. This will probably take the form of a version of
runtests() which rather than printing its output returns raw data on the
state of the tests. (Partially done in Test::Harness::Straps)

Document the format.

Fix HARNESS_COMPILE_TEST without breaking its core usage.

Figure a way to report test names in the failure summary.

Rework the test summary so long test names are not truncated as badly.
(Partially done with new skip test styles)

Deal with VMS's "not \nok 4\n" mistake.

Add option for coverage analysis.

Trap STDERR.

Implement Straps total_results()

Remember exit code

Completely redo the print summary code.

Implement Straps callbacks. (experimentally implemented)

Straps->analyze_file() not taint clean, don't know if it can be

Fix that damned VMS nit.

HARNESS_TODOFAIL to display TODO failures

Add a test for verbose.

Change internal list of test results to a hash.

Fix stats display when there's an overrun.

Fix so perls with spaces in the filename work.

Keeping whittling away at _run_all_tests()

Clean up how the summary is printed. Get rid of those damned formats.

BUGS
HARNESS_COMPILE_TEST currently assumes it's run from the Perl source
directory.

Please use the CPAN bug ticketing system at <http://rt.cpan.org/>. You can
also mail bugs, fixes and enhancements to "<bug-test-harness@rt.cpan.org>".

AUTHORS
Original code by Michael G Schwern, maintained by Andy Lester.

This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.

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

Index for
Section 3

Alphabetical
listing for T

Top of
page

Test::Harness(3)

NAME

VERSION

SYNOPSIS

DESCRIPTION

EXPORT

DIAGNOSTICS

ENVIRONMENT

EXAMPLE

SEE ALSO

AUTHORS

LICENSE

TODO

BUGS

AUTHORS

COPYRIGHT