Unix/Linux Go Back    

RedHat 9 (Linux i386) - man page for test::more (redhat section 3pm)

Linux & Unix Commands - Search Man Pages
Man Page or Keyword Search:   man
Select Man Page Set:       apropos Keyword Search (sections above)

Test::More(3pm) 		 Perl Programmers Reference Guide		  Test::More(3pm)

       Test::More - yet another framework for writing test scripts

	 use Test::More tests => $Num_Tests;
	 # or
	 use Test::More qw(no_plan);
	 # or
	 use Test::More skip_all => $reason;

	 BEGIN { use_ok( 'Some::Module' ); }
	 require_ok( 'Some::Module' );

	 # Various ways to say "ok"
	 ok($this eq $that, $test_name);

	 is  ($this, $that,    $test_name);
	 isnt($this, $that,    $test_name);

	 # Rather than print STDERR "# here's what went wrong\n"
	 diag("here's what went wrong");

	 like  ($this, qr/that/, $test_name);
	 unlike($this, qr/that/, $test_name);

	 cmp_ok($this, '==', $that, $test_name);

	 is_deeply($complex_structure1, $complex_structure2, $test_name);

	 SKIP: {
	     skip $why, $how_many unless $have_some_feature;

	     ok( foo(),       $test_name );
	     is( foo(42), 23, $test_name );

	 TODO: {
	     local $TODO = $why;

	     ok( foo(),       $test_name );
	     is( foo(42), 23, $test_name );

	 can_ok($module, @methods);
	 isa_ok($object, $class);


	 # Utility comparison functions.
	 eq_array(\@this, \@that);
	 eq_hash(\%this, \%that);
	 eq_set(\@this, \@that);

	 my @status = Test::More::status;


       STOP! If you're just getting started writing tests, have a look at Test::Simple first.
       This is a drop in replacement for Test::Simple which you can switch to once you get the
       hang of basic testing.

       The purpose of this module is to provide a wide range of testing utilities.  Various ways
       to say "ok" with better diagnostics, facilities to skip tests, test future features and
       compare complicated data structures.  While you can do almost anything with a simple
       "ok()" function, it doesn't provide good diagnostic output.

       I love it when a plan comes together

       Before anything else, you need a testing plan.  This basically declares how many tests
       your script is going to run to protect against premature failure.

       The preferred way to do this is to declare a plan when you "use Test::More".

	 use Test::More tests => $Num_Tests;

       There are rare cases when you will not know beforehand how many tests your script is going
       to run.	In this case, you can declare that you have no plan.  (Try to avoid using this as
       it weakens your test.)

	 use Test::More qw(no_plan);

       In some cases, you'll want to completely skip an entire testing script.

	 use Test::More skip_all => $skip_reason;

       Your script will declare a skip with the reason why you skipped and exit immediately with
       a zero (success).  See Test::Harness for details.

       If you want to control what functions Test::More will export, you have to use the 'import'
       option.	For example, to import everything but 'fail', you'd do:

	 use Test::More tests => 23, import => ['!fail'];

       Alternatively, you can use the plan() function.	Useful for when you have to calculate the
       number of tests.

	 use Test::More;
	 plan tests => keys %Stuff * 3;

       or for deciding between running the tests at all:

	 use Test::More;
	 if( $^O eq 'MacOS' ) {
	     plan skip_all => 'Test irrelevant on MacOS';
	 else {
	     plan tests => 42;

       Test names

       By convention, each test is assigned a number in order.	This is largely done automati-
       cally for you.  However, it's often very useful to assign a name to each test.  Which
       would you rather see:

	 ok 4
	 not ok 5
	 ok 6


	 ok 4 - basic multi-variable
	 not ok 5 - simple exponential
	 ok 6 - force == mass * acceleration

       The later gives you some idea of what failed.  It also makes it easier to find the test in
       your script, simply search for "simple exponential".

       All test functions take a name argument.  It's optional, but highly suggested that you use

       I'm ok, you're not ok.

       The basic purpose of this module is to print out either "ok #" or "not ok #" depending on
       if a given test succeeded or failed.  Everything else is just gravy.

       All of the following print "ok" or "not ok" depending on if the test succeeded or failed.
       They all also return true or false, respectively.

	     ok($this eq $that, $test_name);

	   This simply evaluates any expression ("$this eq $that" is just a simple example) and
	   uses that to determine if the test succeeded or failed.  A true expression passes, a
	   false one fails.  Very simple.

	   For example:

	       ok( $exp{9} == 81,		    'simple exponential' );
	       ok( Film->can('db_Main'),	    'set_db()' );
	       ok( $p->tests == 4,		    'saw tests' );
	       ok( !grep !defined $_, @items,	    'items populated' );

	   (Mnemonic:  "This is ok.")

	   $test_name is a very short description of the test that will be printed out.  It makes
	   it very easy to find a test in your script when it fails and gives others an idea of
	   your intentions.  $test_name is optional, but we very strongly encourage its use.

	   Should an ok() fail, it will produce some diagnostics:

	       not ok 18 - sufficient mucus
	       #     Failed test 18 (foo.t at line 42)

	   This is actually Test::Simple's ok() routine.

	     is  ( $this, $that, $test_name );
	     isnt( $this, $that, $test_name );

	   Similar to ok(), is() and isnt() compare their two arguments with "eq" and "ne"
	   respectively and use the result of that to determine if the test succeeded or failed.
	   So these:

	       # Is the ultimate answer 42?
	       is( ultimate_answer(), 42,	   "Meaning of Life" );

	       # $foo isn't empty
	       isnt( $foo, '',	   "Got some foo" );

	   are similar to these:

	       ok( ultimate_answer() eq 42,	   "Meaning of Life" );
	       ok( $foo ne '',	   "Got some foo" );

	   (Mnemonic:  "This is that."	"This isn't that.")

	   So why use these?  They produce better diagnostics on failure.  ok() cannot know what
	   you are testing for (beyond the name), but is() and isnt() know what the test was and
	   why it failed.  For example this test:

	       my $foo = 'waffle';  my $bar = 'yarblokos';
	       is( $foo, $bar,	 'Is foo the same as bar?' );

	   Will produce something like this:

	       not ok 17 - Is foo the same as bar?
	       #     Failed test (foo.t at line 139)
	       #	  got: 'waffle'
	       #     expected: 'yarblokos'

	   So you can figure out what went wrong without rerunning the test.

	   You are encouraged to use is() and isnt() over ok() where possible, however do not be
	   tempted to use them to find out if something is true or false!

	     # XXX BAD!  $pope->isa('Catholic') eq 1
	     is( $pope->isa('Catholic'), 1,	   'Is the Pope Catholic?' );

	   This does not check if "$pope-"isa('Catholic')> is true, it checks if it returns 1.
	   Very different.  Similar caveats exist for false and 0.  In these cases, use ok().

	     ok( $pope->isa('Catholic') ),	   'Is the Pope Catholic?' );

	   For those grammatical pedants out there, there's an "isn't()" function which is an
	   alias of isnt().

	     like( $this, qr/that/, $test_name );

	   Similar to ok(), like() matches $this against the regex "qr/that/".

	   So this:

	       like($this, qr/that/, 'this is like that');

	   is similar to:

	       ok( $this =~ /that/, 'this is like that');

	   (Mnemonic "This is like that".)

	   The second argument is a regular expression.  It may be given as a regex reference
	   (i.e. "qr//") or (for better compatibility with older perls) as a string that looks
	   like a regex (alternative delimiters are currently not supported):

	       like( $this, '/that/', 'this is like that' );

	   Regex options may be placed on the end ('/that/i').

	   Its advantages over ok() are similar to that of is() and isnt().  Better diagnostics
	   on failure.

	     unlike( $this, qr/that/, $test_name );

	   Works exactly as like(), only it checks if $this does not match the given pattern.

	     cmp_ok( $this, $op, $that, $test_name );

	   Halfway between ok() and is() lies cmp_ok().  This allows you to compare two arguments
	   using any binary perl operator.

	       # ok( $this eq $that );
	       cmp_ok( $this, 'eq', $that, 'this eq that' );

	       # ok( $this == $that );
	       cmp_ok( $this, '==', $that, 'this == that' );

	       # ok( $this && $that );
	       cmp_ok( $this, '&&', $that, 'this || that' );

	   Its advantage over ok() is when the test fails you'll know what $this and $that were:

	       not ok 1
	       #     Failed test (foo.t at line 12)
	       #     '23'
	       #	 &&
	       #     undef

	   It's also useful in those cases where you are comparing numbers and is()'s use of "eq"
	   will interfere:

	       cmp_ok( $big_hairy_number, '==', $another_big_hairy_number );

	     can_ok($module, @methods);
	     can_ok($object, @methods);

	   Checks to make sure the $module or $object can do these @methods (works with func-
	   tions, too).

	       can_ok('Foo', qw(this that whatever));

	   is almost exactly like saying:

	       ok( Foo->can('this') &&
		   Foo->can('that') &&

	   only without all the typing and with a better interface.  Handy for quickly testing an

	   No matter how many @methods you check, a single can_ok() call counts as one test.  If
	   you desire otherwise, use:

	       foreach my $meth (@methods) {
		   can_ok('Foo', $meth);

	     isa_ok($object, $class, $object_name);
	     isa_ok($ref,    $type,  $ref_name);

	   Checks to see if the given $object->isa($class).  Also checks to make sure the object
	   was defined in the first place.  Handy for this sort of thing:

	       my $obj = Some::Module->new;
	       isa_ok( $obj, 'Some::Module' );

	   where you'd otherwise have to write

	       my $obj = Some::Module->new;
	       ok( defined $obj && $obj->isa('Some::Module') );

	   to safeguard against your test script blowing up.

	   It works on references, too:

	       isa_ok( $array_ref, 'ARRAY' );

	   The diagnostics of this test normally just refer to 'the object'.  If you'd like them
	   to be more specific, you can supply an $object_name (for example 'Test customer').


	   Sometimes you just want to say that the tests have passed.  Usually the case is you've
	   got some complicated condition that is difficult to wedge into an ok().  In this case,
	   you can simply use pass() (to declare the test ok) or fail (for not ok).  They are
	   synonyms for ok(1) and ok(0).

	   Use these very, very, very sparingly.


       If you pick the right test function, you'll usually get a good idea of what went wrong
       when it failed.	But sometimes it doesn't work out that way.  So here we have ways for you
       to write your own diagnostic messages which are safer than just "print STDERR".


	   Prints a diagnostic message which is guaranteed not to interfere with test output.
	   Handy for this sort of thing:

	       ok( grep(/foo/, @users), "There's a foo user" ) or
		   diag("Since there's no foo, check that /etc/bar is set up right");

	   which would produce:

	       not ok 42 - There's a foo user
	       #     Failed test (foo.t at line 52)
	       # Since there's no foo, check that /etc/bar is set up right.

	   You might remember "ok() or diag()" with the mnemonic "open() or die()".

	   NOTE The exact formatting of the diagnostic output is still changing, but it is guar-
	   anteed that whatever you throw at it it won't interfere with the test.

       Module tests

       You usually want to test if the module you're testing loads ok, rather than just vomiting
       if its load fails.  For such purposes we have "use_ok" and "require_ok".

	      BEGIN { use_ok($module); }
	      BEGIN { use_ok($module, @imports); }

	   These simply use the given $module and test to make sure the load happened ok.  It's
	   recommended that you run use_ok() inside a BEGIN block so its functions are exported
	   at compile-time and prototypes are properly honored.

	   If @imports are given, they are passed through to the use.  So this:

	      BEGIN { use_ok('Some::Module', qw(foo bar)) }

	   is like doing this:

	      use Some::Module qw(foo bar);

	   don't try to do this:

	      BEGIN {

		  ...some code that depends on the use...
		  ...happening at compile time...

	   instead, you want:

	     BEGIN { use_ok('Some::Module') }
	     BEGIN { ...some code that depends on the use... }


	   Like use_ok(), except it requires the $module.

       Conditional tests

       Sometimes running a test under certain conditions will cause the test script to die.  A
       certain function or method isn't implemented (such as fork() on MacOS), some resource
       isn't available (like a net connection) or a module isn't available.  In these cases it's
       necessary to skip tests, or declare that they are supposed to fail but will work in the
       future (a todo test).

       For more details on the mechanics of skip and todo tests see Test::Harness.

       The way Test::More handles this is with a named block.  Basically, a block of tests which
       can be skipped over or made todo.  It's best if I just show you...

       SKIP: BLOCK
	     SKIP: {
		 skip $why, $how_many if $condition;

		 ...normal testing code goes here...

	   This declares a block of tests that might be skipped, $how_many tests there are, $why
	   and under what $condition to skip them.  An example is the easiest way to illustrate:

	       SKIP: {
		   eval { require HTML::Lint };

		   skip "HTML::Lint not installed", 2 if $@;

		   my $lint = new HTML::Lint;
		   isa_ok( $lint, "HTML::Lint" );

		   $lint->parse( $html );
		   is( $lint->errors, 0, "No errors found in HTML" );

	   If the user does not have HTML::Lint installed, the whole block of code won't be run
	   at all.  Test::More will output special ok's which Test::Harness interprets as
	   skipped, but passing, tests.  It's important that $how_many accurately reflects the
	   number of tests in the SKIP block so the # of tests run will match up with your plan.

	   It's perfectly safe to nest SKIP blocks.  Each SKIP block must have the label "SKIP",
	   or Test::More can't work its magic.

	   You don't skip tests which are failing because there's a bug in your program, or for
	   which you don't yet have code written.  For that you use TODO.  Read on.

       TODO: BLOCK
	       TODO: {
		   local $TODO = $why if $condition;

		   ...normal testing code goes here...

	   Declares a block of tests you expect to fail and $why.  Perhaps it's because you
	   haven't fixed a bug or haven't finished a new feature:

	       TODO: {
		   local $TODO = "URI::Geller not finished";

		   my $card = "Eight of clubs";
		   is( URI::Geller->your_card, $card, 'Is THIS your card?' );

		   my $spoon;
		   is( $spoon, 'bent',	  "Spoon bending, that's original" );

	   With a todo block, the tests inside are expected to fail.  Test::More will run the
	   tests normally, but print out special flags indicating they are "todo".  Test::Harness
	   will interpret failures as being ok.  Should anything succeed, it will report it as an
	   unexpected success.	You then know the thing you had todo is done and can remove the
	   TODO flag.

	   The nice part about todo tests, as opposed to simply commenting out a block of tests,
	   is it's like having a programmatic todo list.  You know how much work is left to be
	   done, you're aware of what bugs there are, and you'll know immediately when they're

	   Once a todo test starts succeeding, simply move it outside the block.  When the block
	   is empty, delete it.

	       TODO: {
		   todo_skip $why, $how_many if $condition;

		   ...normal testing code...

	   With todo tests, it's best to have the tests actually run.  That way you'll know when
	   they start passing.	Sometimes this isn't possible.	Often a failing test will cause
	   the whole program to die or hang, even inside an "eval BLOCK" with and using "alarm".
	   In these extreme cases you have no choice but to skip over the broken tests entirely.

	   The syntax and behavior is similar to a "SKIP: BLOCK" except the tests will be marked
	   as failing but todo.  Test::Harness will interpret them as passing.

       When do I use SKIP vs. TODO?
	   If it's something the user might not be able to do, use SKIP.  This includes optional
	   modules that aren't installed, running under an OS that doesn't have some feature
	   (like fork() or symlinks), or maybe you need an Internet connection and one isn't

	   If it's something the programmer hasn't done yet, use TODO.	This is for any code you
	   haven't written yet, or bugs you have yet to fix, but want to put tests in your test-
	   ing script (always a good idea).

       Comparison functions

       Not everything is a simple eq check or regex.  There are times you need to see if two
       arrays are equivalent, for instance.  For these instances, Test::More provides a handful
       of useful functions.

       NOTE These are NOT well-tested on circular references.  Nor am I quite sure what will hap-
       pen with filehandles.

	     is_deeply( $this, $that, $test_name );

	   Similar to is(), except that if $this and $that are hash or array references, it does
	   a deep comparison walking each data structure to see if they are equivalent.  If the
	   two structures are different, it will display the place where they start differing.

	   Barrie Slaymaker's Test::Differences module provides more in-depth functionality along
	   these lines, and it plays well with Test::More.

	   NOTE Display of scalar refs is not quite 100%

	     eq_array(\@this, \@that);

	   Checks if two arrays are equivalent.  This is a deep check, so multi-level structures
	   are handled correctly.

	     eq_hash(\%this, \%that);

	   Determines if the two hashes contain the same keys and values.  This is a deep check.

	     eq_set(\@this, \@that);

	   Similar to eq_array(), except the order of the elements is not important.  This is a
	   deep check, but the irrelevancy of order only applies to the top level.

	   NOTE By historical accident, this is not a true set comparision.  While the order of
	   elements does not matter, duplicate elements do.

       Extending and Embedding Test::More

       Sometimes the Test::More interface isn't quite enough.  Fortunately, Test::More is built
       on top of Test::Builder which provides a single, unified backend for any test library to
       use.  This means two test libraries which both use Test::Builder can be used together in
       the same program.

       If you simply want to do a little tweaking of how the tests behave, you can access the
       underlying Test::Builder object like so:

	       my $test_builder = Test::More->builder;

	   Returns the Test::Builder object underlying Test::More for you to play with.

       Test::More is explicitly tested all the way back to perl 5.004.

       Test::More is thread-safe for perl 5.8.0 and up.

       Making your own ok()
	   If you are trying to extend Test::More, don't.  Use Test::Builder instead.

       The eq_* family has some caveats.
       Test::Harness upgrades
	   no_plan and todo depend on new Test::Harness features and fixes.  If you're going to
	   distribute tests that use no_plan or todo your end-users will have to upgrade
	   Test::Harness to the latest one on CPAN.  If you avoid no_plan and TODO tests, the
	   stock Test::Harness will work fine.

	   If you simply depend on Test::More, it's own dependencies will cause a Test::Harness

       This is a case of convergent evolution with Joshua Pritikin's Test module.  I was largely
       unaware of its existence when I'd first written my own ok() routines.  This module exists
       because I can't figure out how to easily wedge test names into Test's interface (along
       with a few other problems).

       The goal here is to have a testing utility that's simple to learn, quick to use and diffi-
       cult to trip yourself up with while still providing more flexibility than the existing
       Test.pm.  As such, the names of the most common routines are kept tiny, special cases and
       magic side-effects are kept to a minimum.  WYSIWYG.

       Test::Simple if all this confuses you and you just want to write some tests.  You can
       upgrade to Test::More later (it's forward compatible).

       Test::Differences for more ways to test complex data structures.  And it plays well with

       Test is the old testing module.	Its main benefit is that it has been distributed with
       Perl since 5.004_05.

       Test::Harness for details on how your test results are interpreted by Perl.

       Test::Unit describes a very featureful unit testing interface.

       Test::Inline shows the idea of embedded testing.

       SelfTest is another approach to embedded testing.

       Michael G Schwern <schwern@pobox.com> with much inspiration from Joshua Pritikin's Test
       module and lots of help from Barrie Slaymaker, Tony Bowden, chromatic and the perl-qa

       Copyright 2001 by Michael G Schwern <schwern@pobox.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

perl v5.8.0				    2002-06-01				  Test::More(3pm)
Unix & Linux Commands & Man Pages : ©2000 - 2018 Unix and Linux Forums

All times are GMT -4. The time now is 10:38 AM.