The Template::Test module defines the test_expect() and other related
subroutines which can be used to automate test scripts for the
Template Toolkit. See the numerous tests in the 't' sub-directory of
the distribution for examples of use.
The test_expect() subroutine splits an input document into a number
of separate tests, processes each one using the Template Toolkit and
then compares the generated output against an expected output, also
specified in the input document. It generates the familiar "ok/not
ok" output compatible with Test::Harness.
The test input should be specified as a text string or a reference to
a filehandle (e.g. GLOB or IO::Handle) from which it can be read. In
particular, this allows the test input to be placed after the __END__
marker and read via the DATA filehandle.
use Template::Test;
test_expect(\*DATA);
__END__
# this is the first test (this is a comment)
-- test --
blah blah blah [% foo %]
-- expect --
blah blah blah value_of_foo
# here's the second test (no surprise, so is this)
-- test --
more blah blah [% bar %]
-- expect --
more blah blah value_of_bar
Blank lines between test sections are generally ignored. Any line starting
with '#' is treated as a comment and is ignored.
The second and third parameters to test_expect() are optional. The second
may be either a reference to a Template object which should be used to
process the template fragments, or a reference to a hash array containing
configuration values which should be used to instantiate a new Template
object.
# pass reference to config hash
my $config = {
INCLUDE_PATH => '/here/there:/every/where',
POST_CHOMP => 1,
};
test_expect(\*DATA, $config);
# or create Template object explicitly
my $template = Template->new($config);
test_expect(\*DATA, $template);
The third parameter may be used to reference a hash array of template
variable which should be defined when processing the tests. This is
passed to the Template process() method.
my $replace = {
a => 'alpha',
b => 'bravo',
};
test_expect(\*DATA, $config, $replace);
The second parameter may be left undefined to specify a default Template
configuration.
test_expect(\*DATA, undef, $replace);
For testing the output of different Template configurations, a
reference to a list of named Template objects also may be passed as
the second parameter.
my $tt1 = Template->new({ ... });
my $tt2 = Template->new({ ... });
my @tts = [ one => $tt1, two => $tt1 ];
The first object in the list is used by default. Other objects may be
switched in with the '-- use $name --' marker. This should immediately
follow a '-- test --' line. That object will then be used for the rest
of the test, or until a different object is selected.
-- test --
-- use one --
[% blah %]
-- expect --
blah, blah
-- test --
still using one...
-- expect --
...
-- test --
-- use two --
[% blah %]
-- expect --
blah, blah, more blah
The test_expect() sub counts the number of tests, and then calls ntests()
to generate the familiar "1..$ntests\n" test harness line. Each
test defined generates two test numbers. The first indicates
that the input was processed without error, and the second that the
output matches that expected.
Additional test may be run before test_expect() by calling ok().
These test results are cached until ntests() is called and the final
number of tests can be calculated. Then, the "1..$ntests" line is
output, along with "ok $n" / "not ok $n" lines for each of the cached
test result. Subsequent calls to ok() then generate an output line
immediately.
my $something = SomeObject->new();
ok( $something );
my $other = AnotherThing->new();
ok( $other );
test_expect(\*DATA);
If any tests are to follow after test_expect() is called then these
should be pre-declared by setting the $EXTRA package variable. This
value (default: 0) is added to the grand total calculated by ntests().
The results of the additional tests are also registered by calling ok().
$Template::Test::EXTRA = 2;
# can call ok() any number of times before test_expect()
ok( $did_that_work );
ok( $make_sure );
ok( $dead_certain );
# <some> number of tests...
test_expect(\*DATA, $config, $replace);
# here's those $EXTRA tests
ok( defined $some_result && ref $some_result eq 'ARRAY' );
ok( $some_result->[0] eq 'some expected value' );
If you don't want to call test_expect() at all then you can call
ntests($n) to declare the number of tests and generate the test
header line. After that, simply call ok() for each test passing
a true or false values to indicate that the test passed or failed.
ntests(2);
ok(1);
ok(0);
If you're really lazy, you can just call ok() and not bother declaring
the number of tests at all. All tests results will be cached until the
end of the script and then printed in one go before the program exits.
ok( $x );
ok( $y );
You can identify only a specific part of the input file for testing
using the '-- start --' and '-- stop --' markers. Anything before the
first '-- start --' is ignored, along with anything after the next
'-- stop --' marker.
-- test --
this is test 1 (not performed)
-- expect --
this is test 1 (not performed)
-- start --
-- test --
this is test 2
-- expect --
this is test 2
-- stop --
...
For historical reasons and general utility, the module also defines a
'callsign' subroutine which returns a hash mapping a..z to their phonetic
alphabet equivalent (e.g. radio callsigns). This is used by many
of the test scripts as a "known source" of variable values.
test_expect(\*DATA, $config, callsign());
A banner() subroutine is also provided which prints a simple banner
including any text passed as parameters, if $DEBUG is set.
banner('Testing something-or-other');
example output:
#------------------------------------------------------------
# Testing something-or-other (27 tests completed)
#------------------------------------------------------------
The $DEBUG package variable can be set to enable debugging mode.
The $PRESERVE package variable can be set to stop the test_expect()
from converting newlines in the output and expected output into
the literal strings '\n'.
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