* Re: [gentoo-perl] test
2006-09-07 17:29 ` Michael Cummings
@ 2006-09-07 17:29 ` Michael Cummings
2006-09-07 18:12 ` Chris White
1 sibling, 0 replies; 7+ messages in thread
From: Michael Cummings @ 2006-09-07 17:29 UTC (permalink / raw
To: gentoo-perl; +Cc: gentoo-perl
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dams wrote:
> test
NAME
Test - provides a simple framework for writing test scripts
SYNOPSIS
use strict;
use Test;
# use a BEGIN block so we print our plan before MyModule is loaded
BEGIN { plan tests => 14, todo => [3,4] }
# load your module...
use MyModule;
# Helpful notes. All note-lines must start with a "#".
print "# I'm testing MyModule version $MyModule::VERSION\n";
ok(0); # failure
ok(1); # success
ok(0); # ok, expected failure (see todo list, above)
ok(1); # surprise success!
ok(0,1); # failure: '0' ne '1'
ok('broke','fixed'); # failure: 'broke' ne 'fixed'
ok('fixed','fixed'); # success: 'fixed' eq 'fixed'
ok('fixed',qr/x/); # success: 'fixed' =~ qr/x/
ok(sub { 1+1 }, 2); # success: '2' eq '2'
ok(sub { 1+1 }, 3); # failure: '2' ne '3'
my @list = (0,0);
ok @list, 3, "\@list=".join(',',@list); #extra notes
ok 'segmentation fault', '/(?i)success/'; #regex match
skip(
$^O =~ m/MSWin/ ? "Skip if MSWin" : 0, # whether to skip
$foo, $bar # arguments just like for ok(...)
);
skip(
$^O =~ m/MSWin/ ? 0 : "Skip unless MSWin", # whether to skip
$foo, $bar # arguments just like for ok(...)
);
DESCRIPTION
This module simplifies the task of writing test files for Perl modules,
such that their output is in the format that Test::Harness expects to
see.
QUICK START GUIDE
To write a test for your new (and probably not even done) module, create
a new file called t/test.t (in a new t directory). If you have multiple
test files, to test the "foo", "bar", and "baz" feature sets, then feel
free to call your files t/foo.t, t/bar.t, and t/baz.t
Functions
This module defines three public functions, "plan(...)", "ok(...)", and
"skip(...)". By default, all three are exported by the "use Test;"
statement.
"plan(...)"
BEGIN { plan %theplan; }
This should be the first thing you call in your test script. It
declares your testing plan, how many there will be, if any of them
should be allowed to fail, and so on.
Typical usage is just:
use Test;
BEGIN { plan tests => 23 }
These are the things that you can put in the parameters to plan:
"tests => *number*"
The number of tests in your script. This means all ok() and
skip() calls.
"todo => [*1,5,14*]"
A reference to a list of tests which are allowed to fail. See
"TODO TESTS".
"onfail => sub { ... }"
"onfail => \&some_sub"
A subroutine reference to be run at the end of the test script,
if any of the tests fail. See "ONFAIL".
You must call "plan(...)" once and only once. You should call it in
a "BEGIN {...}" block, like so:
BEGIN { plan tests => 23 }
"ok(...)"
ok(1 + 1 == 2);
ok($have, $expect);
ok($have, $expect, $diagnostics);
This function is the reason for "Test"'s existence. It's the basic
function that handles printing ""ok"" or ""not ok"", along with the
current test number. (That's what "Test::Harness" wants to see.)
In its most basic usage, "ok(...)" simply takes a single scalar
expression. If its value is true, the test passes; if false, the
test fails. Examples:
# Examples of ok(scalar)
ok( 1 + 1 == 2 ); # ok if 1 + 1 == 2
ok( $foo =~ /bar/ ); # ok if $foo contains 'bar'
ok( baz($x + $y) eq 'Armondo' ); # ok if baz($x + $y) returns
# 'Armondo'
ok( @a == @b ); # ok if @a and @b are the same
length
The expression is evaluated in scalar context. So the following will
work:
ok( @stuff ); # ok if @stuff has any
elements
ok( !grep !defined $_, @stuff ); # ok if everything in
@stuff is
# defined.
A special case is if the expression is a subroutine reference (in
either "sub {...}" syntax or "\&foo" syntax). In that case, it is
executed and its value (true or false) determines if the test passes
or fails. For example,
ok( sub { # See whether sleep works at least passably
my $start_time = time;
sleep 5;
time() - $start_time >= 4
});
In its two-argument form, "ok(*arg1*, *arg2*)" compares the two
scalar values to see if they match. They match if both are
undefined, or if *arg2* is a regex that matches *arg1*, or if they
compare equal with "eq".
# Example of ok(scalar, scalar)
ok( "this", "that" ); # not ok, 'this' ne 'that'
ok( "", undef ); # not ok, "" is defined
The second argument is considered a regex if it is either a regex
object or a string that looks like a regex. Regex objects are
constructed with the qr// operator in recent versions of perl. A
string is considered to look like a regex if its first and last
characters are "/", or if the first character is "m" and its second
and last characters are both the same non-alphanumeric
non-whitespace character. These regexp
Regex examples:
ok( 'JaffO', '/Jaff/' ); # ok, 'JaffO' =~ /Jaff/
ok( 'JaffO', 'm|Jaff|' ); # ok, 'JaffO' =~ m|Jaff|
ok( 'JaffO', qr/Jaff/ ); # ok, 'JaffO' =~ qr/Jaff/;
ok( 'JaffO', '/(?i)jaff/ ); # ok, 'JaffO' =~ /jaff/i;
If either (or both!) is a subroutine reference, it is run and used
as the value for comparing. For example:
ok sub {
open(OUT, ">x.dat") || die $!;
print OUT "\x{e000}";
close OUT;
my $bytecount = -s 'x.dat';
unlink 'x.dat' or warn "Can't unlink : $!";
return $bytecount;
},
4
;
The above test passes two values to "ok(arg1, arg2)" -- the first a
coderef, and the second is the number 4. Before "ok" compares them,
it calls the coderef, and uses its return value as the real value of
this parameter. Assuming that $bytecount returns 4, "ok" ends up
testing "4 eq 4". Since that's true, this test passes.
Finally, you can append an optional third argument, in
"ok(*arg1*,*arg2*, *note*)", where *note* is a string value that
will be printed if the test fails. This should be some useful
information about the test, pertaining to why it failed, and/or a
description of the test. For example:
ok( grep($_ eq 'something unique', @stuff), 1,
"Something that should be unique isn't!\n".
'@stuff = '.join ', ', @stuff
);
Unfortunately, a note cannot be used with the single argument style
of "ok()". That is, if you try "ok(*arg1*, *note*)", then "Test"
will interpret this as "ok(*arg1*, *arg2*)", and probably end up
testing "*arg1* eq *arg2*" -- and that's not what you want!
All of the above special cases can occasionally cause some problems.
See "BUGS and CAVEATS".
"skip(*skip_if_true*, *args...*)"
This is used for tests that under some conditions can be skipped.
It's basically equivalent to:
if( $skip_if_true ) {
ok(1);
} else {
ok( args... );
}
...except that the ok(1) emits not just ""ok *testnum*"" but
actually ""ok *testnum* # *skip_if_true_value*"".
The arguments after the *skip_if_true* are what is fed to "ok(...)"
if this test isn't skipped.
Example usage:
my $if_MSWin =
$^O =~ m/MSWin/ ? 'Skip if under MSWin' : '';
# A test to be skipped if under MSWin (i.e., run except under
MSWin)
skip($if_MSWin, thing($foo), thing($bar) );
Or, going the other way:
my $unless_MSWin =
$^O =~ m/MSWin/ ? '' : 'Skip unless under MSWin';
# A test to be skipped unless under MSWin (i.e., run only
under MSWin)
skip($unless_MSWin, thing($foo), thing($bar) );
The tricky thing to remember is that the first parameter is true if
you want to *skip* the test, not *run* it; and it also doubles as a
note about why it's being skipped. So in the first codeblock above,
read the code as "skip if MSWin -- (otherwise) test whether
"thing($foo)" is "thing($bar)"" or for the second case, "skip unless
MSWin...".
Also, when your *skip_if_reason* string is true, it really should
(for backwards compatibility with older Test.pm versions) start with
the string "Skip", as shown in the above examples.
Note that in the above cases, "thing($foo)" and "thing($bar)" *are*
evaluated -- but as long as the "skip_if_true" is true, then we
"skip(...)" just tosses out their value (i.e., not bothering to
treat them like values to "ok(...)". But if you need to *not* eval
the arguments when skipping the test, use this format:
skip( $unless_MSWin,
sub {
# This code returns true if the test passes.
# (But it doesn't even get called if the test is skipped.)
thing($foo) eq thing($bar)
}
);
or even this, which is basically equivalent:
skip( $unless_MSWin,
sub { thing($foo) }, sub { thing($bar) }
);
That is, both are like this:
if( $unless_MSWin ) {
ok(1); # but it actually appends "# $unless_MSWin"
# so that Test::Harness can tell it's a skip
} else {
# Not skipping, so actually call and evaluate...
ok( sub { thing($foo) }, sub { thing($bar) } );
}
TEST TYPES
* NORMAL TESTS
These tests are expected to succeed. Usually, most or all of your
tests are in this category. If a normal test doesn't succeed, then
that means that something is *wrong*.
* SKIPPED TESTS
The "skip(...)" function is for tests that might or might not be
possible to run, depending on the availability of platform-specific
features. The first argument should evaluate to true (think "yes,
please skip") if the required feature is *not* available. After the
first argument, "skip(...)" works exactly the same way as "ok(...)"
does.
* TODO TESTS
TODO tests are designed for maintaining an executable TODO list.
These tests are *expected to fail.* If a TODO test does succeed,
then the feature in question shouldn't be on the TODO list, now
should it?
Packages should NOT be released with succeeding TODO tests. As soon
as a TODO test starts working, it should be promoted to a normal
test, and the newly working feature should be documented in the
release notes or in the change log.
ONFAIL
BEGIN { plan test => 4, onfail => sub { warn "CALL 911!" } }
Although test failures should be enough, extra diagnostics can be
triggered at the end of a test run. "onfail" is passed an array ref of
hash refs that describe each test failure. Each hash will contain at
least the following fields: "package", "repetition", and "result". (You
shouldn't rely on any other fields being present.) If the test had an
expected value or a diagnostic (or "note") string, these will also be
included.
The *optional* "onfail" hook might be used simply to print out the
version of your package and/or how to report problems. It might also be
used to generate extremely sophisticated diagnostics for a particularly
bizarre test failure. However it's not a panacea. Core dumps or other
unrecoverable errors prevent the "onfail" hook from running. (It is run
inside an "END" block.) Besides, "onfail" is probably over-kill in most
cases. (Your test code should be simpler than the code it is testing,
yes?)
BUGS and CAVEATS
* "ok(...)"'s special handing of strings which look like they might be
regexes can also cause unexpected behavior. An innocent:
ok( $fileglob, '/path/to/some/*stuff/' );
will fail, since Test.pm considers the second argument to be a
regex! The best bet is to use the one-argument form:
ok( $fileglob eq '/path/to/some/*stuff/' );
* "ok(...)"'s use of string "eq" can sometimes cause odd problems when
comparing numbers, especially if you're casting a string to a
number:
$foo = "1.0";
ok( $foo, 1 ); # not ok, "1.0" ne 1
Your best bet is to use the single argument form:
ok( $foo == 1 ); # ok "1.0" == 1
* As you may have inferred from the above documentation and examples,
"ok"'s prototype is "($;$$)" (and, incidentally, "skip"'s is
"($;$$$)"). This means, for example, that you can do "ok @foo, @bar"
to compare the *size* of the two arrays. But don't be fooled into
thinking that "ok @foo, @bar" means a comparison of the contents of
two arrays -- you're comparing *just* the number of elements of
each. It's so easy to make that mistake in reading "ok @foo, @bar"
that you might want to be very explicit about it, and instead write
"ok scalar(@foo), scalar(@bar)".
* This almost definitely doesn't do what you expect:
ok $thingy->can('some_method');
Why? Because "can" returns a coderef to mean "yes it can (and the
method is this...)", and then "ok" sees a coderef and thinks you're
passing a function that you want it to call and consider the truth
of the result of! I.e., just like:
ok $thingy->can('some_method')->();
What you probably want instead is this:
ok $thingy->can('some_method') && 1;
If the "can" returns false, then that is passed to "ok". If it
returns true, then the larger expression
"$thingy->can('some_method') && 1" returns 1, which "ok" sees as a
simple signal of success, as you would expect.
* The syntax for "skip" is about the only way it can be, but it's
still quite confusing. Just start with the above examples and you'll
be okay.
Moreover, users may expect this:
skip $unless_mswin, foo($bar), baz($quux);
to not evaluate "foo($bar)" and "baz($quux)" when the test is being
skipped. But in reality, they *are* evaluated, but "skip" just won't
bother comparing them if $unless_mswin is true.
You could do this:
skip $unless_mswin, sub{foo($bar)}, sub{baz($quux)};
But that's not terribly pretty. You may find it simpler or clearer
in the long run to just do things like this:
if( $^O =~ m/MSWin/ ) {
print "# Yay, we're under $^O\n";
ok foo($bar), baz($quux);
ok thing($whatever), baz($stuff);
ok blorp($quux, $whatever);
ok foo($barzbarz), thang($quux);
} else {
print "# Feh, we're under $^O. Watch me skip some tests...\n";
for(1 .. 4) { skip "Skip unless under MSWin" }
}
But be quite sure that "ok" is called exactly as many times in the
first block as "skip" is called in the second block.
ENVIRONMENT
If "PERL_TEST_DIFF" environment variable is set, it will be used as a
command for comparing unexpected multiline results. If you have GNU diff
installed, you might want to set "PERL_TEST_DIFF" to "diff -u". If you
don't have a suitable program, you might install the "Text::Diff" module
and then set "PERL_TEST_DIFF" to be "perl -MText::Diff -e 'print
diff(@ARGV)'". If "PERL_TEST_DIFF" isn't set but the "Algorithm::Diff"
module is available, then it will be used to show the differences in
multiline results.
NOTE
A past developer of this module once said that it was no longer being
actively developed. However, rumors of its demise were greatly
exaggerated. Feedback and suggestions are quite welcome.
Be aware that the main value of this module is its simplicity. Note that
there are already more ambitious modules out there, such as Test::More
and Test::Unit.
Some earlier versions of this module had docs with some confusing typoes
in the description of "skip(...)".
SEE ALSO
Test::Harness
Test::Simple, Test::More, Devel::Cover
Test::Builder for building your own testing library.
Test::Unit is an interesting XUnit-style testing library.
Test::Inline and SelfTest let you embed tests in code.
AUTHOR
Copyright (c) 1998-2000 Joshua Nathaniel Pritikin. All rights reserved.
Copyright (c) 2001-2002 Michael G. Schwern.
Copyright (c) 2002-2004 and counting Sean M. Burke.
Current maintainer: Sean M. Burke. <sburke@cpan.org>
This package is free software and is provided "as is" without express or
implied warranty. It may be used, redistributed and/or modified under
the same terms as Perl itself.
- --
- -----o()o----------------------------------------------
Michael Cummings | #gentoo-dev, #gentoo-perl
Gentoo Perl Dev | on irc.freenode.net
Gentoo/SPARC
Gentoo/AMD64
GPG: 0543 6FA3 5F82 3A76 3BF7 8323 AB5C ED4E 9E7F 4E2E
- -----o()o----------------------------------------------
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gentoo-perl@gentoo.org mailing list
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [gentoo-perl] test
2006-09-07 17:29 ` Michael Cummings
2006-09-07 17:29 ` Michael Cummings
@ 2006-09-07 18:12 ` Chris White
1 sibling, 0 replies; 7+ messages in thread
From: Chris White @ 2006-09-07 18:12 UTC (permalink / raw
To: gentoo-perl
[-- Attachment #1: Type: text/plain, Size: 19357 bytes --]
On Thursday 07 September 2006 10:29, Michael Cummings wrote:
> dams wrote:
> > test
>
> NAME
> Test - provides a simple framework for writing test scripts
>
> SYNOPSIS
> use strict;
> use Test;
>
> # use a BEGIN block so we print our plan before MyModule is loaded
> BEGIN { plan tests => 14, todo => [3,4] }
>
> # load your module...
> use MyModule;
>
> # Helpful notes. All note-lines must start with a "#".
> print "# I'm testing MyModule version $MyModule::VERSION\n";
>
> ok(0); # failure
> ok(1); # success
>
> ok(0); # ok, expected failure (see todo list, above)
> ok(1); # surprise success!
>
> ok(0,1); # failure: '0' ne '1'
> ok('broke','fixed'); # failure: 'broke' ne 'fixed'
> ok('fixed','fixed'); # success: 'fixed' eq 'fixed'
> ok('fixed',qr/x/); # success: 'fixed' =~ qr/x/
>
> ok(sub { 1+1 }, 2); # success: '2' eq '2'
> ok(sub { 1+1 }, 3); # failure: '2' ne '3'
>
> my @list = (0,0);
> ok @list, 3, "\@list=".join(',',@list); #extra notes
> ok 'segmentation fault', '/(?i)success/'; #regex match
>
> skip(
> $^O =~ m/MSWin/ ? "Skip if MSWin" : 0, # whether to skip
> $foo, $bar # arguments just like for ok(...)
> );
> skip(
> $^O =~ m/MSWin/ ? 0 : "Skip unless MSWin", # whether to skip
> $foo, $bar # arguments just like for ok(...)
> );
>
> DESCRIPTION
> This module simplifies the task of writing test files for Perl modules,
> such that their output is in the format that Test::Harness expects to
> see.
>
> QUICK START GUIDE
> To write a test for your new (and probably not even done) module,
> create a new file called t/test.t (in a new t directory). If you have
> multiple test files, to test the "foo", "bar", and "baz" feature sets, then
> feel free to call your files t/foo.t, t/bar.t, and t/baz.t
>
> Functions
> This module defines three public functions, "plan(...)", "ok(...)", and
> "skip(...)". By default, all three are exported by the "use Test;"
> statement.
>
> "plan(...)"
> BEGIN { plan %theplan; }
>
> This should be the first thing you call in your test script. It
> declares your testing plan, how many there will be, if any of them
> should be allowed to fail, and so on.
>
> Typical usage is just:
>
> use Test;
> BEGIN { plan tests => 23 }
>
> These are the things that you can put in the parameters to plan:
>
> "tests => *number*"
> The number of tests in your script. This means all ok() and
> skip() calls.
>
> "todo => [*1,5,14*]"
> A reference to a list of tests which are allowed to fail. See
> "TODO TESTS".
>
> "onfail => sub { ... }"
> "onfail => \&some_sub"
> A subroutine reference to be run at the end of the test script,
> if any of the tests fail. See "ONFAIL".
>
> You must call "plan(...)" once and only once. You should call it in
> a "BEGIN {...}" block, like so:
>
> BEGIN { plan tests => 23 }
>
> "ok(...)"
> ok(1 + 1 == 2);
> ok($have, $expect);
> ok($have, $expect, $diagnostics);
>
> This function is the reason for "Test"'s existence. It's the basic
> function that handles printing ""ok"" or ""not ok"", along with the
> current test number. (That's what "Test::Harness" wants to see.)
>
> In its most basic usage, "ok(...)" simply takes a single scalar
> expression. If its value is true, the test passes; if false, the
> test fails. Examples:
>
> # Examples of ok(scalar)
>
> ok( 1 + 1 == 2 ); # ok if 1 + 1 == 2
> ok( $foo =~ /bar/ ); # ok if $foo contains 'bar'
> ok( baz($x + $y) eq 'Armondo' ); # ok if baz($x + $y)
> returns # 'Armondo'
> ok( @a == @b ); # ok if @a and @b are the same
> length
>
> The expression is evaluated in scalar context. So the following
> will work:
>
> ok( @stuff ); # ok if @stuff has any
> elements
> ok( !grep !defined $_, @stuff ); # ok if everything in
> @stuff is
> # defined.
>
> A special case is if the expression is a subroutine reference (in
> either "sub {...}" syntax or "\&foo" syntax). In that case, it is
> executed and its value (true or false) determines if the test
> passes or fails. For example,
>
> ok( sub { # See whether sleep works at least passably
> my $start_time = time;
> sleep 5;
> time() - $start_time >= 4
> });
>
> In its two-argument form, "ok(*arg1*, *arg2*)" compares the two
> scalar values to see if they match. They match if both are
> undefined, or if *arg2* is a regex that matches *arg1*, or if they
> compare equal with "eq".
>
> # Example of ok(scalar, scalar)
>
> ok( "this", "that" ); # not ok, 'this' ne 'that'
> ok( "", undef ); # not ok, "" is defined
>
> The second argument is considered a regex if it is either a regex
> object or a string that looks like a regex. Regex objects are
> constructed with the qr// operator in recent versions of perl. A
> string is considered to look like a regex if its first and last
> characters are "/", or if the first character is "m" and its second
> and last characters are both the same non-alphanumeric
> non-whitespace character. These regexp
>
> Regex examples:
>
> ok( 'JaffO', '/Jaff/' ); # ok, 'JaffO' =~ /Jaff/
> ok( 'JaffO', 'm|Jaff|' ); # ok, 'JaffO' =~ m|Jaff|
> ok( 'JaffO', qr/Jaff/ ); # ok, 'JaffO' =~ qr/Jaff/;
> ok( 'JaffO', '/(?i)jaff/ ); # ok, 'JaffO' =~ /jaff/i;
>
> If either (or both!) is a subroutine reference, it is run and used
> as the value for comparing. For example:
>
> ok sub {
> open(OUT, ">x.dat") || die $!;
> print OUT "\x{e000}";
> close OUT;
> my $bytecount = -s 'x.dat';
> unlink 'x.dat' or warn "Can't unlink : $!";
> return $bytecount;
> },
> 4
> ;
>
> The above test passes two values to "ok(arg1, arg2)" -- the first a
> coderef, and the second is the number 4. Before "ok" compares them,
> it calls the coderef, and uses its return value as the real value
> of this parameter. Assuming that $bytecount returns 4, "ok" ends up testing
> "4 eq 4". Since that's true, this test passes.
>
> Finally, you can append an optional third argument, in
> "ok(*arg1*,*arg2*, *note*)", where *note* is a string value that
> will be printed if the test fails. This should be some useful
> information about the test, pertaining to why it failed, and/or a
> description of the test. For example:
>
> ok( grep($_ eq 'something unique', @stuff), 1,
> "Something that should be unique isn't!\n".
> '@stuff = '.join ', ', @stuff
> );
>
> Unfortunately, a note cannot be used with the single argument style
> of "ok()". That is, if you try "ok(*arg1*, *note*)", then "Test"
> will interpret this as "ok(*arg1*, *arg2*)", and probably end up
> testing "*arg1* eq *arg2*" -- and that's not what you want!
>
> All of the above special cases can occasionally cause some
> problems. See "BUGS and CAVEATS".
>
> "skip(*skip_if_true*, *args...*)"
> This is used for tests that under some conditions can be skipped.
> It's basically equivalent to:
>
> if( $skip_if_true ) {
> ok(1);
> } else {
> ok( args... );
> }
>
> ...except that the ok(1) emits not just ""ok *testnum*"" but
> actually ""ok *testnum* # *skip_if_true_value*"".
>
> The arguments after the *skip_if_true* are what is fed to "ok(...)"
> if this test isn't skipped.
>
> Example usage:
>
> my $if_MSWin =
> $^O =~ m/MSWin/ ? 'Skip if under MSWin' : '';
>
> # A test to be skipped if under MSWin (i.e., run except under
> MSWin)
> skip($if_MSWin, thing($foo), thing($bar) );
>
> Or, going the other way:
>
> my $unless_MSWin =
> $^O =~ m/MSWin/ ? '' : 'Skip unless under MSWin';
>
> # A test to be skipped unless under MSWin (i.e., run only
> under MSWin)
> skip($unless_MSWin, thing($foo), thing($bar) );
>
> The tricky thing to remember is that the first parameter is true if
> you want to *skip* the test, not *run* it; and it also doubles as a
> note about why it's being skipped. So in the first codeblock above,
> read the code as "skip if MSWin -- (otherwise) test whether
> "thing($foo)" is "thing($bar)"" or for the second case, "skip
> unless MSWin...".
>
> Also, when your *skip_if_reason* string is true, it really should
> (for backwards compatibility with older Test.pm versions) start
> with the string "Skip", as shown in the above examples.
>
> Note that in the above cases, "thing($foo)" and "thing($bar)" *are*
> evaluated -- but as long as the "skip_if_true" is true, then we
> "skip(...)" just tosses out their value (i.e., not bothering to
> treat them like values to "ok(...)". But if you need to *not* eval
> the arguments when skipping the test, use this format:
>
> skip( $unless_MSWin,
> sub {
> # This code returns true if the test passes.
> # (But it doesn't even get called if the test is skipped.)
> thing($foo) eq thing($bar)
> }
> );
>
> or even this, which is basically equivalent:
>
> skip( $unless_MSWin,
> sub { thing($foo) }, sub { thing($bar) }
> );
>
> That is, both are like this:
>
> if( $unless_MSWin ) {
> ok(1); # but it actually appends "# $unless_MSWin"
> # so that Test::Harness can tell it's a skip
> } else {
> # Not skipping, so actually call and evaluate...
> ok( sub { thing($foo) }, sub { thing($bar) } );
> }
>
> TEST TYPES
> * NORMAL TESTS
> These tests are expected to succeed. Usually, most or all of your
> tests are in this category. If a normal test doesn't succeed, then
> that means that something is *wrong*.
>
> * SKIPPED TESTS
> The "skip(...)" function is for tests that might or might not be
> possible to run, depending on the availability of platform-specific
> features. The first argument should evaluate to true (think "yes,
> please skip") if the required feature is *not* available. After the
> first argument, "skip(...)" works exactly the same way as "ok(...)"
> does.
>
> * TODO TESTS
> TODO tests are designed for maintaining an executable TODO list.
> These tests are *expected to fail.* If a TODO test does succeed,
> then the feature in question shouldn't be on the TODO list, now
> should it?
>
> Packages should NOT be released with succeeding TODO tests. As soon
> as a TODO test starts working, it should be promoted to a normal
> test, and the newly working feature should be documented in the
> release notes or in the change log.
>
> ONFAIL
> BEGIN { plan test => 4, onfail => sub { warn "CALL 911!" } }
>
> Although test failures should be enough, extra diagnostics can be
> triggered at the end of a test run. "onfail" is passed an array ref of
> hash refs that describe each test failure. Each hash will contain at
> least the following fields: "package", "repetition", and "result". (You
> shouldn't rely on any other fields being present.) If the test had an
> expected value or a diagnostic (or "note") string, these will also be
> included.
>
> The *optional* "onfail" hook might be used simply to print out the
> version of your package and/or how to report problems. It might also be
> used to generate extremely sophisticated diagnostics for a particularly
> bizarre test failure. However it's not a panacea. Core dumps or other
> unrecoverable errors prevent the "onfail" hook from running. (It is run
> inside an "END" block.) Besides, "onfail" is probably over-kill in most
> cases. (Your test code should be simpler than the code it is testing,
> yes?)
>
> BUGS and CAVEATS
> * "ok(...)"'s special handing of strings which look like they might
> be regexes can also cause unexpected behavior. An innocent:
>
> ok( $fileglob, '/path/to/some/*stuff/' );
>
> will fail, since Test.pm considers the second argument to be a
> regex! The best bet is to use the one-argument form:
>
> ok( $fileglob eq '/path/to/some/*stuff/' );
>
> * "ok(...)"'s use of string "eq" can sometimes cause odd problems
> when comparing numbers, especially if you're casting a string to a number:
>
> $foo = "1.0";
> ok( $foo, 1 ); # not ok, "1.0" ne 1
>
> Your best bet is to use the single argument form:
>
> ok( $foo == 1 ); # ok "1.0" == 1
>
> * As you may have inferred from the above documentation and examples,
> "ok"'s prototype is "($;$$)" (and, incidentally, "skip"'s is
> "($;$$$)"). This means, for example, that you can do "ok @foo,
> @bar" to compare the *size* of the two arrays. But don't be fooled into
> thinking that "ok @foo, @bar" means a comparison of the contents of two
> arrays -- you're comparing *just* the number of elements of each. It's so
> easy to make that mistake in reading "ok @foo, @bar" that you might want to
> be very explicit about it, and instead write "ok scalar(@foo),
> scalar(@bar)".
>
> * This almost definitely doesn't do what you expect:
>
> ok $thingy->can('some_method');
>
> Why? Because "can" returns a coderef to mean "yes it can (and the
> method is this...)", and then "ok" sees a coderef and thinks you're
> passing a function that you want it to call and consider the truth
> of the result of! I.e., just like:
>
> ok $thingy->can('some_method')->();
>
> What you probably want instead is this:
>
> ok $thingy->can('some_method') && 1;
>
> If the "can" returns false, then that is passed to "ok". If it
> returns true, then the larger expression
> "$thingy->can('some_method') && 1" returns 1, which "ok" sees as a
> simple signal of success, as you would expect.
>
> * The syntax for "skip" is about the only way it can be, but it's
> still quite confusing. Just start with the above examples and
> you'll be okay.
>
> Moreover, users may expect this:
>
> skip $unless_mswin, foo($bar), baz($quux);
>
> to not evaluate "foo($bar)" and "baz($quux)" when the test is being
> skipped. But in reality, they *are* evaluated, but "skip" just
> won't bother comparing them if $unless_mswin is true.
>
> You could do this:
>
> skip $unless_mswin, sub{foo($bar)}, sub{baz($quux)};
>
> But that's not terribly pretty. You may find it simpler or clearer
> in the long run to just do things like this:
>
> if( $^O =~ m/MSWin/ ) {
> print "# Yay, we're under $^O\n";
> ok foo($bar), baz($quux);
> ok thing($whatever), baz($stuff);
> ok blorp($quux, $whatever);
> ok foo($barzbarz), thang($quux);
> } else {
> print "# Feh, we're under $^O. Watch me skip some tests...\n";
> for(1 .. 4) { skip "Skip unless under MSWin" }
> }
>
> But be quite sure that "ok" is called exactly as many times in the
> first block as "skip" is called in the second block.
>
> ENVIRONMENT
> If "PERL_TEST_DIFF" environment variable is set, it will be used as a
> command for comparing unexpected multiline results. If you have GNU
> diff installed, you might want to set "PERL_TEST_DIFF" to "diff -u". If you
> don't have a suitable program, you might install the "Text::Diff" module
> and then set "PERL_TEST_DIFF" to be "perl -MText::Diff -e 'print
> diff(@ARGV)'". If "PERL_TEST_DIFF" isn't set but the "Algorithm::Diff"
> module is available, then it will be used to show the differences in
> multiline results.
>
> NOTE
> A past developer of this module once said that it was no longer being
> actively developed. However, rumors of its demise were greatly
> exaggerated. Feedback and suggestions are quite welcome.
>
> Be aware that the main value of this module is its simplicity. Note
> that there are already more ambitious modules out there, such as Test::More
> and Test::Unit.
>
> Some earlier versions of this module had docs with some confusing
> typoes in the description of "skip(...)".
>
> SEE ALSO
> Test::Harness
>
> Test::Simple, Test::More, Devel::Cover
>
> Test::Builder for building your own testing library.
>
> Test::Unit is an interesting XUnit-style testing library.
>
> Test::Inline and SelfTest let you embed tests in code.
>
> AUTHOR
> Copyright (c) 1998-2000 Joshua Nathaniel Pritikin. All rights reserved.
>
> Copyright (c) 2001-2002 Michael G. Schwern.
>
> Copyright (c) 2002-2004 and counting Sean M. Burke.
>
> Current maintainer: Sean M. Burke. <sburke@cpan.org>
>
> This package is free software and is provided "as is" without express
> or implied warranty. It may be used, redistributed and/or modified under
> the same terms as Perl itself.
>
>
>
> --
>
> -----o()o----------------------------------------------
> Michael Cummings | #gentoo-dev, #gentoo-perl
> Gentoo Perl Dev | on irc.freenode.net
> Gentoo/SPARC
> Gentoo/AMD64
> GPG: 0543 6FA3 5F82 3A76 3BF7 8323 AB5C ED4E 9E7F 4E2E
> -----o()o----------------------------------------------
I agree. (sorry couldn't help it ;p)
--
Chris White
Gentoo Developer aka:
ChrisWhite cpw
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