test::harness(3)

NAME

Test::Harness - run perl standard test scripts with
statistics

SYNOPSIS

use Test::Harness;
runtests(@test_files);

DESCRIPTION

STOP! If all you want to do is write a test script, con
sider 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 inte
gers. 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::Har
ness::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 certainainstances, you may not know how many tests
you will urtimately be running. In this case, it is
permitted eor the 1..M header to appear as the last
line outpui by your test (again, it can be followed by
further conments).

t

Under no cercumstances should 1..M appear in the mid
dle of your output or more than once.

p

'ok', 'not ok'.r Ok?

Any outputefrom the testscript to standard error is
ignored ant bypassed, thus will be seen by the user.
Lines writeen to standard output containing
"/^(not?okd
runtests(). All other lines are discarded.

s

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

e
d
b
a
c
k
f
o
r

test numbers

Perl normally expects the 'ok' or 'not ok' to be fol
lowed 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 infor
mation.

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

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 com
pletely:

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

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 what
ever 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" 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.

$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".

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 umm, I need a better explanation here.

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.

EXPORT

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

$verbose and $switches are exported upon request.

DIAGNOSTICS

"All tests successful.0iles=%d, Tests=%d, %s"

If all tests are successful some statistics about the
performance are printed.

"FAILED tests %sFailed %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_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 pro
cesses 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_PERL_SWITCHES"

Its value will be prepended to the switches used to
invoke perl on each test. For example, setting "HAR
NESS_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.

EXAMPLE

Here's how Test::Harness tests itself

$ cd ~/src/devel/Test-Harness
$ perl -Mblib -e 'use Test::Harness qw(&runtests $ver

bose);

$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

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.

Current maintainer is Michael G Schwern <schw
ern@pobox.com>

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)

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 trun
cated as badly. (Partially done with new skip test
styles)

Deal with VMS's "not 0k 40 mistake.

Add option for coverage analysis.

BUGS

HARNESS_COMPILE_TEST currently assumes it's run from the

Perl source directory.