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TAP::Parser(3pm) Perl Programmers Reference Guide TAP::Parser(3pm)

NAME

TAP::Parser - Parse TAP output

VERSION

Version 3.17

SYNOPSIS

    use TAP::Parser;
    my $parser = TAP::Parser->new( { source => $source } );
    while ( my $result = $parser->next ) {
        print $result->as_string;
    }

DESCRIPTION

"TAP::Parser" is designed to produce a proper parse of TAP output. For an example of how to run tests through this module, see the simple harnesses "examples/".

There's a wiki dedicated to the Test Anything Protocol:

<http://testanything.org>

It includes the TAP::Parser Cookbook:

<http://testanything.org/wiki/index.php/TAP::Parser_Cookbook>

METHODS

Class Methods

"new"

 my $parser = TAP::Parser->new(\%args);

Returns a new "TAP::Parser" object.

The arguments should be a hashref with one of the following keys:

  • "source"

    This is the preferred method of passing arguments to the constructor. To determine how to handle the source, the following steps are taken.

    If the source contains a newline, it's assumed to be a string of raw TAP output.

    If the source is a reference, it's assumed to be something to pass to the TAP::Parser::Iterator::Stream constructor. This is used internally and you should not use it.

    Otherwise, the parser does a "-e" check to see if the source exists. If so, it attempts to execute the source and read the output as a stream. This is by far the preferred method of using the parser.

     foreach my $file ( @test_files ) {
         my $parser = TAP::Parser->new( { source => $file } );
         # do stuff with the parser
     }
        
  • "tap"

    The value should be the complete TAP output.

  • "exec"

    If passed an array reference, will attempt to create the iterator by passing a TAP::Parser::Source object to TAP::Parser::Iterator::Source, using the array reference strings as the command arguments to IPC::Open3::open3:

     exec => [ '/usr/bin/ruby', 't/my_test.rb' ]
        

    Note that "source" and "exec" are mutually exclusive.

The following keys are optional.

  • "callback"

    If present, each callback corresponding to a given result type will be called with the result as the argument if the "run" method is used:

     my %callbacks = (
         test    => \&test_callback,
         plan    => \&plan_callback,
         comment => \&comment_callback,
         bailout => \&bailout_callback,
         unknown => \&unknown_callback,
     );
     my $aggregator = TAP::Parser::Aggregator->new;
     foreach my $file ( @test_files ) {
         my $parser = TAP::Parser->new(
             {
                 source    => $file,
                 callbacks => \%callbacks,
             }
         );
         $parser->run;
         $aggregator->add( $file, $parser );
     }
        
  • "switches"

    If using a Perl file as a source, optional switches may be passed which will be used when invoking the perl executable.

     my $parser = TAP::Parser->new( {
         source   => $test_file,
         switches => '-Ilib',
     } );
        
  • "test_args"

    Used in conjunction with the "source" option to supply a reference to an @ARGV style array of arguments to pass to the test program.

  • "spool"

    If passed a filehandle will write a copy of all parsed TAP to that handle.

  • "merge"

    If false, STDERR is not captured (though it is 'relayed' to keep it somewhat synchronized with STDOUT.)

    If true, STDERR and STDOUT are the same filehandle. This may cause breakage if STDERR contains anything resembling TAP format, but does allow exact synchronization.

    Subtleties of this behavior may be platform-dependent and may change in the future.

  • "source_class"

    This option was introduced to let you easily customize which source class the parser should use. It defaults to TAP::Parser::Source.

    See also "make_source".

  • "perl_source_class"

    This option was introduced to let you easily customize which perl source class the parser should use. It defaults to TAP::Parser::Source::Perl.

    See also "make_perl_source".

  • "grammar_class"

    This option was introduced to let you easily customize which grammar class the parser should use. It defaults to TAP::Parser::Grammar.

    See also "make_grammar".

  • "iterator_factory_class"

    This option was introduced to let you easily customize which iterator factory class the parser should use. It defaults to TAP::Parser::IteratorFactory.

    See also "make_iterator".

  • "result_factory_class"

    This option was introduced to let you easily customize which result factory class the parser should use. It defaults to TAP::Parser::ResultFactory.

    See also "make_result".

Instance Methods

"next"

  my $parser = TAP::Parser->new( { source => $file } );
  while ( my $result = $parser->next ) {
      print $result->as_string, "\n";
  }

This method returns the results of the parsing, one result at a time. Note that it is destructive. You can't rewind and examine previous results.

If callbacks are used, they will be issued before this call returns.

Each result returned is a subclass of TAP::Parser::Result. See that module and related classes for more information on how to use them.

"run"

  $parser->run;

This method merely runs the parser and parses all of the TAP.

"make_source"

Make a new TAP::Parser::Source object and return it. Passes through any arguments given.

The "source_class" can be customized, as described in "new".

"make_perl_source"

Make a new TAP::Parser::Source::Perl object and return it. Passes through any arguments given.

The "perl_source_class" can be customized, as described in "new".

"make_grammar"

Make a new TAP::Parser::Grammar object and return it. Passes through any arguments given.

The "grammar_class" can be customized, as described in "new".

"make_iterator"

Make a new TAP::Parser::Iterator object using the parser's TAP::Parser::IteratorFactory, and return it. Passes through any arguments given.

The "iterator_factory_class" can be customized, as described in "new".

"make_result"

Make a new TAP::Parser::Result object using the parser's TAP::Parser::ResultFactory, and return it. Passes through any arguments given.

The "result_factory_class" can be customized, as described in "new".

INDIVIDUAL RESULTS

If you've read this far in the docs, you've seen this:

    while ( my $result = $parser->next ) {
        print $result->as_string;
    }

Each result returned is a TAP::Parser::Result subclass, referred to as result types.

Result types

Basically, you fetch individual results from the TAP. The six types, with examples of each, are as follows:

  • Version

     TAP version 12
        
  • Plan

     1..42
        
  • Pragma

     pragma +strict
        
  • Test

     ok 3 - We should start with some foobar!
        
  • Comment

     # Hope we don't use up the foobar.
        
  • Bailout

     Bail out!  We ran out of foobar!
        
  • Unknown

     ... yo, this ain't TAP! ...
        

Each result fetched is a result object of a different type. There are common methods to each result object and different types may have methods unique to their type. Sometimes a type method may be overridden in a subclass, but its use is guaranteed to be identical.

Common type methods

"type"

Returns the type of result, such as "comment" or "test".

"as_string"

Prints a string representation of the token. This might not be the exact output, however. Tests will have test numbers added if not present, TODO and SKIP directives will be capitalized and, in general, things will be cleaned up. If you need the original text for the token, see the "raw" method.

"raw"

Returns the original line of text which was parsed.

"is_plan"

Indicates whether or not this is the test plan line.

"is_test"

Indicates whether or not this is a test line.

"is_comment"

Indicates whether or not this is a comment. Comments will generally only appear in the TAP stream if STDERR is merged to STDOUT. See the "merge" option.

"is_bailout"

Indicates whether or not this is bailout line.

"is_yaml"

Indicates whether or not the current item is a YAML block.

"is_unknown"

Indicates whether or not the current line could be parsed.

"is_ok"

  if ( $result->is_ok ) { ... }

Reports whether or not a given result has passed. Anything which is not a test result returns true. This is merely provided as a convenient shortcut which allows you to do this:

 my $parser = TAP::Parser->new( { source => $source } );
 while ( my $result = $parser->next ) {
     # only print failing results
     print $result->as_string unless $result->is_ok;
 }

"plan" methods

 if ( $result->is_plan ) { ... }

If the above evaluates as true, the following methods will be available on the $result object.

"plan"

  if ( $result->is_plan ) {
     print $result->plan;
  }

This is merely a synonym for "as_string".

"directive"

 my $directive = $result->directive;

If a SKIP directive is included with the plan, this method will return it.

 1..0 # SKIP: why bother?

"explanation"

 my $explanation = $result->explanation;

If a SKIP directive was included with the plan, this method will return the explanation, if any.

"pragma" methods

 if ( $result->is_pragma ) { ... }

If the above evaluates as true, the following methods will be available on the $result object.

"pragmas"

Returns a list of pragmas each of which is a + or - followed by the pragma name.

"commment" methods

 if ( $result->is_comment ) { ... }

If the above evaluates as true, the following methods will be available on the $result object.

"comment"

  if ( $result->is_comment ) {
      my $comment = $result->comment;
      print "I have something to say:  $comment";
  }

"bailout" methods

 if ( $result->is_bailout ) { ... }

If the above evaluates as true, the following methods will be available on the $result object.

"explanation"

  if ( $result->is_bailout ) {
      my $explanation = $result->explanation;
      print "We bailed out because ($explanation)";
  }

If, and only if, a token is a bailout token, you can get an "explanation" via this method. The explanation is the text after the mystical "Bail out!" words which appear in the tap output.

"unknown" methods

 if ( $result->is_unknown ) { ... }

There are no unique methods for unknown results.

"test" methods

 if ( $result->is_test ) { ... }

If the above evaluates as true, the following methods will be available on the $result object.

"ok"

  my $ok = $result->ok;

Returns the literal text of the "ok" or "not ok" status.

"number"

  my $test_number = $result->number;

Returns the number of the test, even if the original TAP output did not supply that number.

"description"

  my $description = $result->description;

Returns the description of the test, if any. This is the portion after the test number but before the directive.

"directive"

  my $directive = $result->directive;

Returns either "TODO" or "SKIP" if either directive was present for a test line.

"explanation"

  my $explanation = $result->explanation;

If a test had either a "TODO" or "SKIP" directive, this method will return the accompanying explantion, if present.

  not ok 17 - 'Pigs can fly' # TODO not enough acid

For the above line, the explanation is not enough acid.

"is_ok"

  if ( $result->is_ok ) { ... }

Returns a boolean value indicating whether or not the test passed. Remember that for TODO tests, the test always passes.

Note: this was formerly "passed". The latter method is deprecated and will issue a warning.

"is_actual_ok"

  if ( $result->is_actual_ok ) { ... }

Returns a boolean value indicating whether or not the test passed, regardless of its TODO status.

Note: this was formerly "actual_passed". The latter method is deprecated and will issue a warning.

"is_unplanned"

  if ( $test->is_unplanned ) { ... }

If a test number is greater than the number of planned tests, this method will return true. Unplanned tests will always return false for "is_ok", regardless of whether or not the test "has_todo" (see TAP::Parser::Result::Test for more information about this).

"has_skip"

  if ( $result->has_skip ) { ... }

Returns a boolean value indicating whether or not this test had a SKIP directive.

"has_todo"

  if ( $result->has_todo ) { ... }

Returns a boolean value indicating whether or not this test had a TODO directive.

Note that TODO tests always pass. If you need to know whether or not they really passed, check the "is_actual_ok" method.

"in_todo"

  if ( $parser->in_todo ) { ... }

True while the most recent result was a TODO. Becomes true before the TODO result is returned and stays true until just before the next non- TODO test is returned.

TOTAL RESULTS

After parsing the TAP, there are many methods available to let you dig through the results and determine what is meaningful to you.

Individual Results

These results refer to individual tests which are run.

"passed"

 my @passed = $parser->passed; # the test numbers which passed
 my $passed = $parser->passed; # the number of tests which passed

This method lets you know which (or how many) tests passed. If a test failed but had a TODO directive, it will be counted as a passed test.

"failed"

 my @failed = $parser->failed; # the test numbers which failed
 my $failed = $parser->failed; # the number of tests which failed

This method lets you know which (or how many) tests failed. If a test passed but had a TODO directive, it will NOT be counted as a failed test.

"actual_passed"

 # the test numbers which actually passed
 my @actual_passed = $parser->actual_passed;
 # the number of tests which actually passed
 my $actual_passed = $parser->actual_passed;

This method lets you know which (or how many) tests actually passed, regardless of whether or not a TODO directive was found.

"actual_ok"

This method is a synonym for "actual_passed".

"actual_failed"

 # the test numbers which actually failed
 my @actual_failed = $parser->actual_failed;
 # the number of tests which actually failed
 my $actual_failed = $parser->actual_failed;

This method lets you know which (or how many) tests actually failed, regardless of whether or not a TODO directive was found.

"todo"

 my @todo = $parser->todo; # the test numbers with todo directives
 my $todo = $parser->todo; # the number of tests with todo directives

This method lets you know which (or how many) tests had TODO directives.

"todo_passed"

 # the test numbers which unexpectedly succeeded
 my @todo_passed = $parser->todo_passed;
 # the number of tests which unexpectedly succeeded
 my $todo_passed = $parser->todo_passed;

This method lets you know which (or how many) tests actually passed but were declared as "TODO" tests.

"todo_failed"

  # deprecated in favor of 'todo_passed'.  This method was horribly misnamed.

This was a badly misnamed method. It indicates which TODO tests unexpectedly succeeded. Will now issue a warning and call "todo_passed".

"skipped"

 my @skipped = $parser->skipped; # the test numbers with SKIP directives
 my $skipped = $parser->skipped; # the number of tests with SKIP directives

This method lets you know which (or how many) tests had SKIP directives.

Pragmas

"pragma"

Get or set a pragma. To get the state of a pragma:

  if ( $p->pragma('strict') ) {
      # be strict
  }

To set the state of a pragma:

  $p->pragma('strict', 1); # enable strict mode

"pragmas"

Get a list of all the currently enabled pragmas:

  my @pragmas_enabled = $p->pragmas;

Summary Results

These results are "meta" information about the total results of an individual test program.

"plan"

 my $plan = $parser->plan;

Returns the test plan, if found.

"good_plan"

Deprecated. Use "is_good_plan" instead.

"is_good_plan"

  if ( $parser->is_good_plan ) { ... }

Returns a boolean value indicating whether or not the number of tests planned matches the number of tests run.

Note: this was formerly "good_plan". The latter method is deprecated and will issue a warning.

And since we're on that subject ...

"tests_planned"

  print $parser->tests_planned;

Returns the number of tests planned, according to the plan. For example, a plan of '1..17' will mean that 17 tests were planned.

"tests_run"

  print $parser->tests_run;

Returns the number of tests which actually were run. Hopefully this will match the number of "$parser->tests_planned".

"skip_all"

Returns a true value (actually the reason for skipping) if all tests were skipped.

"start_time"

Returns the time when the Parser was created.

"end_time"

Returns the time when the end of TAP input was seen.

"has_problems"

  if ( $parser->has_problems ) {
      ...
  }

This is a 'catch-all' method which returns true if any tests have currently failed, any TODO tests unexpectedly succeeded, or any parse errors occurred.

"version"

  $parser->version;

Once the parser is done, this will return the version number for the parsed TAP. Version numbers were introduced with TAP version 13 so if no version number is found version 12 is assumed.

"exit"

  $parser->exit;

Once the parser is done, this will return the exit status. If the parser ran an executable, it returns the exit status of the executable.

"wait"

  $parser->wait;

Once the parser is done, this will return the wait status. If the parser ran an executable, it returns the wait status of the executable. Otherwise, this mererely returns the "exit" status.

"ignore_exit"

  $parser->ignore_exit(1);

Tell the parser to ignore the exit status from the test when determining whether the test passed. Normally tests with non-zero exit status are considered to have failed even if all individual tests passed. In cases where it is not possible to control the exit value of the test script use this option to ignore it.

"parse_errors"

 my @errors = $parser->parse_errors; # the parser errors
 my $errors = $parser->parse_errors; # the number of parser_errors

Fortunately, all TAP output is perfect. In the event that it is not, this method will return parser errors. Note that a junk line which the parser does not recognize is "not" an error. This allows this parser to handle future versions of TAP. The following are all TAP errors reported by the parser:

  • Misplaced plan

    The plan (for example, '1..5'), must only come at the beginning or end of the TAP output.

  • No plan

    Gotta have a plan!

  • More than one plan

     1..3
     ok 1 - input file opened
     not ok 2 - first line of the input valid # todo some data
     ok 3 read the rest of the file
     1..3
        

    Right. Very funny. Don't do that.

  • Test numbers out of sequence

     1..3
     ok 1 - input file opened
     not ok 2 - first line of the input valid # todo some data
     ok 2 read the rest of the file
        

    That last test line above should have the number '3' instead of '2'.

    Note that it's perfectly acceptable for some lines to have test numbers and others to not have them. However, when a test number is found, it must be in sequence. The following is also an error:

     1..3
     ok 1 - input file opened
     not ok - first line of the input valid # todo some data
     ok 2 read the rest of the file
        

    But this is not:

     1..3
     ok  - input file opened
     not ok - first line of the input valid # todo some data
     ok 3 read the rest of the file
        

"get_select_handles"

Get an a list of file handles which can be passed to "select" to determine the readiness of this parser.

"delete_spool"

Delete and return the spool.

  my $fh = $parser->delete_spool;

CALLBACKS

As mentioned earlier, a "callback" key may be added to the "TAP::Parser" constructor. If present, each callback corresponding to a given result type will be called with the result as the argument if the "run" method is used. The callback is expected to be a subroutine reference (or anonymous subroutine) which is invoked with the parser result as its argument.

 my %callbacks = (
     test    => \&test_callback,
     plan    => \&plan_callback,
     comment => \&comment_callback,
     bailout => \&bailout_callback,
     unknown => \&unknown_callback,
 );
 my $aggregator = TAP::Parser::Aggregator->new;
 foreach my $file ( @test_files ) {
     my $parser = TAP::Parser->new(
         {
             source    => $file,
             callbacks => \%callbacks,
         }
     );
     $parser->run;
     $aggregator->add( $file, $parser );
 }

Callbacks may also be added like this:

 $parser->callback( test => \&test_callback );
 $parser->callback( plan => \&plan_callback );

The following keys allowed for callbacks. These keys are case-sensitive.

  • "test"

    Invoked if "$result->is_test" returns true.

  • "version"

    Invoked if "$result->is_version" returns true.

  • "plan"

    Invoked if "$result->is_plan" returns true.

  • "comment"

    Invoked if "$result->is_comment" returns true.

  • "bailout"

    Invoked if "$result->is_unknown" returns true.

  • "yaml"

    Invoked if "$result->is_yaml" returns true.

  • "unknown"

    Invoked if "$result->is_unknown" returns true.

  • "ELSE"

    If a result does not have a callback defined for it, this callback will be invoked. Thus, if all of the previous result types are specified as callbacks, this callback will never be invoked.

  • "ALL"

    This callback will always be invoked and this will happen for each result after one of the above callbacks is invoked. For example, if Term::ANSIColor is loaded, you could use the following to color your test output:

     my %callbacks = (
         test => sub {
             my $test = shift;
             if ( $test->is_ok && not $test->directive ) {
                 # normal passing test
                 print color 'green';
             }
             elsif ( !$test->is_ok ) {    # even if it's TODO
                 print color 'white on_red';
             }
             elsif ( $test->has_skip ) {
                 print color 'white on_blue';
             }
             elsif ( $test->has_todo ) {
                 print color 'white';
             }
         },
         ELSE => sub {
             # plan, comment, and so on (anything which isn't a test line)
             print color 'black on_white';
         },
         ALL => sub {
             # now print them
             print shift->as_string;
             print color 'reset';
             print "\n";
         },
     );
        
  • "EOF"

    Invoked when there are no more lines to be parsed. Since there is no accompanying TAP::Parser::Result object the "TAP::Parser" object is passed instead.

TAP GRAMMAR

If you're looking for an EBNF grammar, see TAP::Parser::Grammar.

BACKWARDS COMPATABILITY

The Perl-QA list attempted to ensure backwards compatability with Test::Harness. However, there are some minor differences.

Differences

  • TODO plans

    A little-known feature of Test::Harness is that it supported TODO lists in the plan:

     1..2 todo 2
     ok 1 - We have liftoff
     not ok 2 - Anti-gravity device activated
        

    Under Test::Harness, test number 2 would pass because it was listed as a TODO test on the plan line. However, we are not aware of anyone actually using this feature and hard-coding test numbers is discouraged because it's very easy to add a test and break the test number sequence. This makes test suites very fragile. Instead, the following should be used:

     1..2
     ok 1 - We have liftoff
     not ok 2 - Anti-gravity device activated # TODO
        
  • 'Missing' tests

    It rarely happens, but sometimes a harness might encounter 'missing tests:

     ok 1
     ok 2
     ok 15
     ok 16
     ok 17
        

    Test::Harness would report tests 3-14 as having failed. For the "TAP::Parser", these tests are not considered failed because they've never run. They're reported as parse failures (tests out of sequence).

SUBCLASSING

If you find you need to provide custom functionality (as you would have using Test::Harness::Straps), you're in luck: "TAP::Parser" and friends are designed to be easily subclassed.

Before you start, it's important to know a few things:

1.
All "TAP::*" objects inherit from TAP::Object.
2.
Most "TAP::*" classes have a SUBCLASSING section to guide you.
3.
Note that "TAP::Parser" is designed to be the central 'maker' - ie: it is responsible for creating new objects in the "TAP::Parser::*" namespace.

This makes it possible for you to have a single point of configuring what subclasses should be used, which in turn means that in many cases you'll find you only need to sub-class one of the parser's components.

4.
By subclassing, you may end up overriding undocumented methods. That's not a bad thing per se, but be forewarned that undocumented methods may change without warning from one release to the next - we cannot guarantee backwards compatability. If any documented method needs changing, it will be deprecated first, and changed in a later release.

Parser Components

Sources

A TAP parser consumes input from a source. There are currently two types of sources: TAP::Parser::Source for general non-perl commands, and TAP::Parser::Source::Perl. You can subclass both of them. You'll need to customize your parser by setting the "source_class" & "perl_source_class" parameters. See "new" for more details.

If you need to customize the objects on creation, subclass TAP::Parser and override "make_source" or "make_perl_source".

Iterators

A TAP parser uses iterators to loop through the stream provided by the parser's source. There are quite a few types of Iterators available. Choosing which class to use is the responsibility of the iterator factory.

To create your own iterators you'll have to subclass TAP::Parser::IteratorFactory and TAP::Parser::Iterator. Then you'll need to customize the class used by your parser by setting the "iterator_factory_class" parameter. See "new" for more details.

If you need to customize the objects on creation, subclass TAP::Parser and override "make_iterator".

Results

A TAP parser creates TAP::Parser::Results as it iterates through the input stream. There are quite a few result types available; choosing which class to use is the responsibility of the result factory.

To create your own result types you have two options:

Subclass TAP::Parser::Result and register your new result type/class with the default TAP::Parser::ResultFactory.
Subclass TAP::Parser::ResultFactory itself and implement your own TAP::Parser::Result creation logic. Then you'll need to customize the class used by your parser by setting the "result_factory_class" parameter. See "new" for more details.

If you need to customize the objects on creation, subclass TAP::Parser and override "make_result".

Grammar

TAP::Parser::Grammar is the heart of the parser - it tokenizes the TAP input stream and produces results. If you need to customize its behaviour you should probably familiarize yourself with the source first. Enough lecturing.

Subclass TAP::Parser::Grammar and customize your parser by setting the "grammar_class" parameter. See "new" for more details.

If you need to customize the objects on creation, subclass TAP::Parser and override "make_grammar"

ACKNOWLEDGEMENTS

All of the following have helped. Bug reports, patches, (im)moral support, or just words of encouragement have all been forthcoming.

  • Michael Schwern
  • Andy Lester
  • chromatic
  • GEOFFR
  • Shlomi Fish
  • Torsten Schoenfeld
  • Jerry Gay
  • Aristotle
  • Adam Kennedy
  • Yves Orton
  • Adrian Howard
  • Sean & Lil
  • Andreas J. Koenig
  • Florian Ragwitz
  • Corion
  • Mark Stosberg
  • Matt Kraai
  • David Wheeler
  • Alex Vandiver

AUTHORS

Curtis "Ovid" Poe <ovid@cpan.org>

Andy Armstong <andy@hexten.net>

Eric Wilhelm @ <ewilhelm at cpan dot org>

Michael Peters <mpeters at plusthree dot com>

Leif Eriksen <leif dot eriksen at bigpond dot com>

Steve Purkis <spurkis@cpan.org>

Nicholas Clark <nick@ccl4.org>

BUGS

Please report any bugs or feature requests to "bug-test-harness@rt.cpan.org", or through the web interface at <http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Test-Harness>. We will be notified, and then you'll automatically be notified of progress on your bug as we make changes.

Obviously, bugs which include patches are best. If you prefer, you can patch against bleed by via anonymous checkout of the latest version:

 svn checkout http://svn.hexten.net/tapx

COPYRIGHT & LICENSE

Copyright 2006-2008 Curtis "Ovid" Poe, all rights reserved.

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

2009-06-12 perl v5.10.1