TAP::Harness(3pm) Perl Programmers Reference Guide TAP::Harness(3pm)NAMETAP::Harness - Run test scripts with statistics
VERSION
Version 3.23
DESCRIPTION
This is a simple test harness which allows tests to be run and results
automatically aggregated and output to STDOUT.
SYNOPSIS
use TAP::Harness;
my $harness = TAP::Harness->new( \%args );
$harness->runtests(@tests);
METHODS
Class Methods
"new"
my %args = (
verbosity => 1,
lib => [ 'lib', 'blib/lib', 'blib/arch' ],
)
my $harness = TAP::Harness->new( \%args );
The constructor returns a new "TAP::Harness" object. It accepts an
optional hashref whose allowed keys are:
· "verbosity"
Set the verbosity level:
1 verbose Print individual test results to STDOUT.
0 normal
-1 quiet Suppress some test output (mostly failures
while tests are running).
-2 really quiet Suppress everything but the tests summary.
-3 silent Suppress everything.
· "timer"
Append run time for each test to output. Uses Time::HiRes if
available.
· "failures"
Show test failures (this is a no-op if "verbose" is selected).
· "comments"
Show test comments (this is a no-op if "verbose" is selected).
· "show_count"
Update the running test count during testing.
· "normalize"
Set to a true value to normalize the TAP that is emitted in verbose
modes.
· "lib"
Accepts a scalar value or array ref of scalar values indicating
which paths to allowed libraries should be included if Perl tests
are executed. Naturally, this only makes sense in the context of
tests written in Perl.
· "switches"
Accepts a scalar value or array ref of scalar values indicating
which switches should be included if Perl tests are executed.
Naturally, this only makes sense in the context of tests written in
Perl.
· "test_args"
A reference to an @INC style array of arguments to be passed to
each test program.
test_args => ['foo', 'bar'],
if you want to pass different arguments to each test then you
should pass a hash of arrays, keyed by the alias for each test:
test_args => {
my_test => ['foo', 'bar'],
other_test => ['baz'],
}
· "color"
Attempt to produce color output.
· "exec"
Typically, Perl tests are run through this. However, anything which
spits out TAP is fine. You can use this argument to specify the
name of the program (and optional switches) to run your tests with:
exec => ['/usr/bin/ruby', '-w']
You can also pass a subroutine reference in order to determine and
return the proper program to run based on a given test script. The
subroutine reference should expect the TAP::Harness object itself
as the first argument, and the file name as the second argument. It
should return an array reference containing the command to be run
and including the test file name. It can also simply return
"undef", in which case TAP::Harness will fall back on executing the
test script in Perl:
exec => sub {
my ( $harness, $test_file ) = @_;
# Let Perl tests run.
return undef if $test_file =~ /[.]t$/;
return [ qw( /usr/bin/ruby -w ), $test_file ]
if $test_file =~ /[.]rb$/;
}
If the subroutine returns a scalar with a newline or a filehandle,
it will be interpreted as raw TAP or as a TAP stream, respectively.
· "merge"
If "merge" is true the harness will create parsers that merge
STDOUT and STDERR together for any processes they start.
· "sources"
NEW to 3.18.
If set, "sources" must be a hashref containing the names of the
TAP::Parser::SourceHandlers to load and/or configure. The values
are a hash of configuration that will be accessible to to the
source handlers via "config_for" in TAP::Parser::Source.
For example:
sources => {
Perl => { exec => '/path/to/custom/perl' },
File => { extensions => [ '.tap', '.txt' ] },
MyCustom => { some => 'config' },
}
The "sources" parameter affects how "source", "tap" and "exec"
parameters are handled.
For more details, see the "sources" parameter in "new" in
TAP::Parser, TAP::Parser::Source, and TAP::Parser::IteratorFactory.
· "aggregator_class"
The name of the class to use to aggregate test results. The default
is TAP::Parser::Aggregator.
· "version"
NEW to 3.22.
Assume this TAP version for TAP::Parser instead of default TAP
version 12.
· "formatter_class"
The name of the class to use to format output. The default is
TAP::Formatter::Console, or TAP::Formatter::File if the output
isn't a TTY.
· "multiplexer_class"
The name of the class to use to multiplex tests during parallel
testing. The default is TAP::Parser::Multiplexer.
· "parser_class"
The name of the class to use to parse TAP. The default is
TAP::Parser.
· "scheduler_class"
The name of the class to use to schedule test execution. The
default is TAP::Parser::Scheduler.
· "formatter"
If set "formatter" must be an object that is capable of formatting
the TAP output. See TAP::Formatter::Console for an example.
· "errors"
If parse errors are found in the TAP output, a note of this will be
made in the summary report. To see all of the parse errors, set
this argument to true:
errors => 1
· "directives"
If set to a true value, only test results with directives will be
displayed. This overrides other settings such as "verbose" or
"failures".
· "ignore_exit"
If set to a true value instruct "TAP::Parser" to ignore exit and
wait status from test scripts.
· "jobs"
The maximum number of parallel tests to run at any time. Which
tests can be run in parallel is controlled by "rules". The default
is to run only one test at a time.
· "rules"
A reference to a hash of rules that control which tests may be
executed in parallel. This is an experimental feature and the
interface may change.
$harness->rules(
{ par => [
{ seq => '../ext/DB_File/t/*' },
{ seq => '../ext/IO_Compress_Zlib/t/*' },
{ seq => '../lib/CPANPLUS/*' },
{ seq => '../lib/ExtUtils/t/*' },
'*'
]
}
);
· "stdout"
A filehandle for catching standard output.
· "trap"
Attempt to print summary information if run is interrupted by
SIGINT (Ctrl-C).
Any keys for which the value is "undef" will be ignored.
Instance Methods
"runtests"
$harness->runtests(@tests);
Accepts an array of @tests to be run. This should generally be the
names of test files, but this is not required. Each element in @tests
will be passed to "TAP::Parser::new()" as a "source". See TAP::Parser
for more information.
It is possible to provide aliases that will be displayed in place of
the test name by supplying the test as a reference to an array
containing "[ $test, $alias ]":
$harness->runtests( [ 't/foo.t', 'Foo Once' ],
[ 't/foo.t', 'Foo Twice' ] );
Normally it is an error to attempt to run the same test twice. Aliases
allow you to overcome this limitation by giving each run of the test a
unique name.
Tests will be run in the order found.
If the environment variable "PERL_TEST_HARNESS_DUMP_TAP" is defined it
should name a directory into which a copy of the raw TAP for each test
will be written. TAP is written to files named for each test.
Subdirectories will be created as needed.
Returns a TAP::Parser::Aggregator containing the test results.
"summary"
$harness->summary( $aggregator );
Output the summary for a TAP::Parser::Aggregator.
"aggregate_tests"
$harness->aggregate_tests( $aggregate, @tests );
Run the named tests and display a summary of result. Tests will be run
in the order found.
Test results will be added to the supplied TAP::Parser::Aggregator.
"aggregate_tests" may be called multiple times to run several sets of
tests. Multiple "Test::Harness" instances may be used to pass results
to a single aggregator so that different parts of a complex test suite
may be run using different "TAP::Harness" settings. This is useful, for
example, in the case where some tests should run in parallel but others
are unsuitable for parallel execution.
my $formatter = TAP::Formatter::Console->new;
my $ser_harness = TAP::Harness->new( { formatter => $formatter } );
my $par_harness = TAP::Harness->new(
{ formatter => $formatter,
jobs => 9
}
);
my $aggregator = TAP::Parser::Aggregator->new;
$aggregator->start();
$ser_harness->aggregate_tests( $aggregator, @ser_tests );
$par_harness->aggregate_tests( $aggregator, @par_tests );
$aggregator->stop();
$formatter->summary($aggregator);
Note that for simpler testing requirements it will often be possible to
replace the above code with a single call to "runtests".
Each element of the @tests array is either:
· the source name of a test to run
· a reference to a [ source name, display name ] array
In the case of a perl test suite, typically source names are simply the
file names of the test scripts to run.
When you supply a separate display name it becomes possible to run a
test more than once; the display name is effectively the alias by which
the test is known inside the harness. The harness doesn't care if it
runs the same test more than once when each invocation uses a different
name.
"make_scheduler"
Called by the harness when it needs to create a TAP::Parser::Scheduler.
Override in a subclass to provide an alternative scheduler.
"make_scheduler" is passed the list of tests that was passed to
"aggregate_tests".
"jobs"
Gets or sets the number of concurrent test runs the harness is
handling. By default, this value is 1 -- for parallel testing, this
should be set higher.
"make_parser"
Make a new parser and display formatter session. Typically used and/or
overridden in subclasses.
my ( $parser, $session ) = $harness->make_parser;
"finish_parser"
Terminate use of a parser. Typically used and/or overridden in
subclasses. The parser isn't destroyed as a result of this.
CONFIGURING
"TAP::Harness" is designed to be easy to configure.
Plugins
"TAP::Parser" plugins let you change the way TAP is input to and output
from the parser.
TAP::Parser::SourceHandlers handle TAP input. You can configure them
and load custom handlers using the "sources" parameter to "new".
TAP::Formatters handle TAP output. You can load custom formatters by
using the "formatter_class" parameter to "new". To configure a
formatter, you currently need to instantiate it outside of TAP::Harness
and pass it in with the "formatter" parameter to "new". This may be
addressed by adding a formatters parameter to "new" in the future.
"Module::Build"
Module::Build version 0.30 supports "TAP::Harness".
To load "TAP::Harness" plugins, you'll need to use the
"tap_harness_args" parameter to "new", typically from your "Build.PL".
For example:
Module::Build->new(
module_name => 'MyApp',
test_file_exts => [qw(.t .tap .txt)],
use_tap_harness => 1,
tap_harness_args => {
sources => {
MyCustom => {},
File => {
extensions => ['.tap', '.txt'],
},
},
formatter => 'TAP::Formatter::HTML',
},
build_requires => {
'Module::Build' => '0.30',
'TAP::Harness' => '3.18',
},
)->create_build_script;
See "new"
"ExtUtils::MakeMaker"
ExtUtils::MakeMaker does not support TAP::Harness out-of-the-box.
"prove"
prove supports "TAP::Harness" plugins, and has a plugin system of its
own. See "FORMATTERS" in prove, "SOURCE HANDLERS" in prove and
App::Prove for more details.
WRITING PLUGINS
If you can't configure "TAP::Harness" to do what you want, and you
can't find an existing plugin, consider writing one.
The two primary use cases supported by TAP::Harness for plugins are
input and output:
Customize how TAP gets into the parser
To do this, you can either extend an existing
TAP::Parser::SourceHandler, or write your own. It's a pretty simple
API, and they can be loaded and configured using the "sources"
parameter to "new".
Customize how TAP results are output from the parser
To do this, you can either extend an existing TAP::Formatter, or
write your own. Writing formatters are a bit more involved than
writing a SourceHandler, as you'll need to understand the TAP::Parser
API. A good place to start is by understanding how "aggregate_tests"
works.
Custom formatters can be loaded configured using the
"formatter_class" parameter to "new".
SUBCLASSING
If you can't configure "TAP::Harness" to do exactly what you want, and
writing a plugin isn't an option, consider extending it. It is
designed to be (mostly) easy to subclass, though the cases when sub-
classing is necessary should be few and far between.
Methods
The following methods are ones you may wish to override if you want to
subclass "TAP::Harness".
"new"
"runtests"
"summary"
REPLACING
If you like the "prove" utility and TAP::Parser but you want your own
harness, all you need to do is write one and provide "new" and
"runtests" methods. Then you can use the "prove" utility like so:
prove --harness My::Test::Harness
Note that while "prove" accepts a list of tests (or things to be
tested), "new" has a fairly rich set of arguments. You'll probably want
to read over this code carefully to see how all of them are being used.
SEE ALSO
Test::Harness
perl v5.16.3 2013-03-04 TAP::Harness(3pm)
