Test::Harness::TAPerl)Programmers ReferenceTest::Harness::TAP(3p)
Test::Harness::TAP - Documentation for the TAP format
TAP, the Test Anything Protocol, is Perl's simple text-based
interface between testing modules such as Test::More and the
test harness Test::Harness.
Exit code of the process.
TAP's general format is:
1..N
ok 1 Description # Directive
# Diagnostic
....
ok 47 Description
ok 48 Description
more tests....
For example, a test file's output might look like:
1..4
ok 1 - Input file opened
not ok 2 - First line of the input valid
ok 3 - Read the rest of the file
not ok 4 - Summarized correctly # TODO Not written yet
In this document, the "harness" is any program analyzing TAP
output. Typically this will be Perl's prove program, or the
underlying "Test::Harness::runtests" subroutine.
A harness must only read TAP output from standard output and
not from standard error. Lines written to standard output
matching "/^(not )?ok\b/" must be interpreted as test lines.
All other lines must not be considered test output.
The plan
The plan tells how many tests will be run, or how many tests
have run. It's a check that the test file hasn't stopped
prematurely. It must appear once, whether at the beginning
or end of the output.
The plan is usually the first line of TAP output and it
specifies how many test points are to follow. For example,
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1..10
means you plan on running 10 tests. This is a safeguard in
case your test file dies silently in the middle of its run.
The plan is optional but if there is a plan before the test
points it must be the first non-diagnostic line output by
the test file.
In certain instances a test file may not know how many test
points it will ultimately be running. In this case the plan
can be the last non-diagnostic line in the output.
The plan cannot appear in the middle of the output, nor can
it appear more than once.
The test line
The core of TAP is the test line. A test file prints one
test line test point executed. There must be at least one
test line in TAP output. Each test line comprises the fol-
lowing elements:
* "ok" or "not ok"
This tells whether the test point passed or failed. It
must be at the beginning of the line. "/^not ok/" indi-
cates a failed test point. "/^ok/" is a successful test
point. This is the only mandatory part of the line.
Note that unlike the Directives below, "ok" and "not ok"
are case-sensitive.
* Test number
TAP expects the "ok" or "not ok" to be followed by a
test point number. If there is no number the harness
must maintain its own counter until the script supplies
test numbers again. So the following test output
1..6
not ok
ok
not ok
ok
ok
has five tests. The sixth is missing. Test::Harness
will generate
FAILED tests 1, 3, 6
Failed 3/6 tests, 50.00% okay
* Description
Any text after the test number but before a "#" is the
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description of the test point.
ok 42 this is the description of the test
Descriptions should not begin with a digit so that they
are not confused with the test point number.
The harness may do whatever it wants with the descrip-
tion.
* Directive
The test point may include a directive, following a hash
on the test line. There are currently two directives
allowed: "TODO" and "SKIP". These are discussed below.
To summarize:
* ok/not ok (required)
* Test number (recommended)
* Description (recommended)
* Directive (only when necessary)
Directives are special notes that follow a "#" on the test
line. Only two are currently defined: "TODO" and "SKIP".
Note that these two keywords are not case-sensitive.
TODO tests
If the directive starts with "# TODO", the test is counted
as a todo test, and the text after "TODO" is the explana-
tion.
not ok 13 # TODO bend space and time
Note that if the TODO has an explanation it must be
separated from "TODO" by a space.
These tests represent a feature to be implemented or a bug
to be fixed and act as something of an executable "things to
do" list. They are not expected to succeed. Should a todo
test point begin succeeding, the harness should 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 point.
Skipping tests
If the directive starts with "# SKIP", the test is counted
as having been skipped. If the whole test file succeeds,
the count of skipped tests is included in the generated out-
put. The harness should report the text after " #
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SKIP\S*\s+" as a reason for skipping.
ok 23 # skip Insufficient flogiston pressure.
Similarly, one can include an explanation in a plan line,
emitted if the test file is skipped completely:
1..0 # Skipped: WWW::Mechanize not installed
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 must be
displayed by the interpreter as the reason why testing must
be stopped, as in
Bail out! MySQL is not running.
Diagnostics
Additional information may be put into the testing output on
separate lines. Diagnostic lines should begin with a "#",
which the harness must ignore, at least as far as analyzing
the test results. The harness is free, however, to display
the diagnostics. Typically diagnostics are used to provide
information about the environment in which test file is run-
ning, or to delineate a group of tests.
...
ok 18 - Closed database connection
# End of database section.
# This starts the network part of the test.
# Daemon started on port 2112
ok 19 - Opened socket
...
ok 47 - Closed socket
# End of network tests
Anything else
Any output line that is not a plan, a test line or a diag-
nostic is incorrect. How a harness handles the incorrect
line is undefined. Test::Harness silently ignores incorrect
lines, but will become more stringent in the future.
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All names, places, and events depicted in any example are
wholly fictitious and bear no resemblance to, connection
with, or relation to any real entity. Any such similarity is
purely coincidental, unintentional, and unintended.
Common with explanation
The following TAP listing declares that six tests follow as
well as provides handy feedback as to what the test is about
to do. All six tests pass.
1..6
#
# Create a new Board and Tile, then place
# the Tile onto the board.
#
ok 1 - The object isa Board
ok 2 - Board size is zero
ok 3 - The object isa Tile
ok 4 - Get possible places to put the Tile
ok 5 - Placing the tile produces no error
ok 6 - Board size is 1
Unknown amount and failures
This hypothetical test program ensures that a handful of
servers are online and network-accessible. Because it
retrieves the hypothetical servers from a database, it
doesn't know exactly how many servers it will need to ping.
Thus, the test count is declared at the bottom after all the
test points have run. Also, two of the tests fail.
ok 1 - retrieving servers from the database
# need to ping 6 servers
ok 2 - pinged diamond
ok 3 - pinged ruby
not ok 4 - pinged saphire
ok 5 - pinged onyx
not ok 6 - pinged quartz
ok 7 - pinged gold
1..7
Giving up
This listing reports that a pile of tests are going to be
run. However, the first test fails, reportedly because a
connection to the database could not be established. The
program decided that continuing was pointless and exited.
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1..573
not ok 1 - database handle
Bail out! Couldn't connect to database.
Skipping a few
The following listing plans on running 5 tests. However, our
program decided to not run tests 2 thru 5 at all. To prop-
erly report this, the tests are marked as being skipped.
1..5
ok 1 - approved operating system
# $^0 is solaris
ok 2 - # SKIP no /sys directory
ok 3 - # SKIP no /sys directory
ok 4 - # SKIP no /sys directory
ok 5 - # SKIP no /sys directory
Skipping everything
This listing shows that the entire listing is a skip. No
tests were run.
1..0 # skip because English-to-French translator isn't installed
Got spare tuits?
The following example reports that four tests are run and
the last two tests failed. However, because the failing
tests are marked as things to do later, they are considered
successes. Thus, a harness should report this entire listing
as a success.
1..4
ok 1 - Creating test program
ok 2 - Test program runs, no error
not ok 3 - infinite loop # TODO halting problem unsolved
not ok 4 - infinite loop 2 # TODO halting problem unsolved
Creative liberties
This listing shows an alternate output where the test
numbers aren't provided. The test also reports the state of
a ficticious board game in diagnostic form. Finally, the
test count is reported at the end.
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ok - created Board
ok
ok
ok
ok
ok
ok
ok
# +------+------+------+------+
# | |16G | |05C |
# | |G N C | |C C G |
# | | G | | C +|
# +------+------+------+------+
# |10C |01G | |03C |
# |R N G |G A G | |C C C |
# | R | G | | C +|
# +------+------+------+------+
# | |01G |17C |00C |
# | |G A G |G N R |R N R |
# | | G | R | G |
# +------+------+------+------+
ok - board has 7 tiles + starter tile
1..9
Andy Lester, based on the original Test::Harness documenta-
tion by Michael Schwern.
Thanks to Pete Krawczyk, Paul Johnson, Ian Langworth and Nik
Clayton for help and contributions on this document.
The basis for the TAP format was created by Larry Wall in
the original test script for Perl 1. Tim Bunce and Andreas
Koenig developed it further with their modifications to
Test::Harness.
Copyright 2003-2005 by Michael G Schwern
"<schwern@pobox.com>", Andy Lester "<andy@petdance.com>".
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>.
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