Unit Tests In Perl

Prerequisite

In order to Unit Test our services with MOBY, we will be using the following Perl modules:

• MOBY::Client::MobyUnitTest (perldoc)
• MOBY::RDF::Parsers::ServiceParser (perldoc)

Additionally, you will need the location of a service’s description. In this tutorial, we will be using the RDF document that describes the service

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Testing the Service

In order to test the service, we need to download and parse the RDF document into a MOBY::Client::ServiceInstance, using the

MOBY::RDF::Parsers::ServiceParser

        # instantiate our ServiceParser with the
        # URL to our Service description
        my $parser =
                 MOBY::RDF::Parsers::ServiceParser->new();

        # parse the RDF document and get our service
        my $service_arrayref = $parser->getServices(
            "http://tinyurl.com/example-unit-test");

Once we have our MOBY::Client::ServiceInstance object, we can get all the unit tests for the object by calling unitTests(). In this case, there is only one MobyUnitTest, so we will take the first one

        # extract the first unit test
        my $unitTest = $service_arrayref->[0]->unitTests()->[0];

Now all that is left is to call the service using the example input (as specified by the service provider)

        # call the synchronous moby service
        my $service_output = doCall($service_name, $service_url, $service_input);

Once we have the output, we can then proceed to test the service.

We can compare the example output to the actual $service_output and get any semantic differences:

        # compare outputXML
        my $success = $unitTest->test_output_xml($service_output);
        print "Expected and actual output matched successfully!\n"
               if $success or $unitTest->expected_output eq "";
        print "There were differences found between the expected and actual output from the service!\n"
               unless $success  or $unitTest->expected_output eq "";

Or, we can apply the regular expression to our $service_output:

        # test against regular expression
        $success = $unitTest->test_regex($service_output);
        print "Regex matched successfully!\n"
             if $success or $unitTest->regex eq "";
        print "Regex didn't match!\n"
             unless  $success or $unitTest->regex eq "";

Or, we can apply the defined XPATH expression to our $service_output:

        # test against xpath expression
        $success = $unitTest->test_xpath($service_output);
        print "XPATH matched successfully!\n" if $success or $unitTest->xpath eq "";
        print "XPATH didn't match!\n" unless $success or $unitTest->xpath eq "";

That is all that there is to unit testing your services in Perl!

 

The full source code for this example:

#!/usr/bin/perl -w

use MOBY::Client::MobyUnitTest;
use MOBY::RDF::Parsers::ServiceParser;
use MOBY::Client::ServiceInstance;
use SOAP::Lite;

use strict;

# instantiate our ServiceInstanceParser with the URL to our
# Service description
my $parser = MOBY::RDF::Parsers::ServiceParser->new();

# parse the RDF document and get our service
my $service_arrayref =
  $parser->getServices("http://tinyurl.com/example-unit-test");

# extract the first unit test
my $unitTest = $service_arrayref->[0]->unitTests()->[0];

my $service_name  = $service_arrayref->[0]->name;
my $service_url   = $service_arrayref->[0]->URL;
my $service_input = $unitTest->example_input;

print "Here is the unit test that we have:\n\n"
  . "\tExample input:\n$service_input\n\n"
  ."\tExpected output:\n"
  . (
	    $unitTest->expected_output eq "" ? "\t\tnone provided."
	  : $unitTest->expected_output
  )
  . "\n\n"
  . "\tXPATH:\n"
  . (
	    $unitTest->xpath eq "" ? "\t\tnone provided."
	  : $unitTest->xpath
  )
  . "\n\n"
  . "\tREGEX:\n"
  . (
	    $unitTest->regex eq "" ? "\t\tnone provided."
	  : $unitTest->regex
  ) . "\n\n\n";

# call the synchronous moby service
my $service_output = doCall( $service_name, $service_url, $service_input );

# compare outputXML
my $success = $unitTest->test_output_xml($service_output);
print "Expected and actual output matched successfully!\n"
  if $success
	  or $unitTest->expected_output eq "";
print
"There were differences found between the expected and actual output from the service!\n"
  unless $success
	  or $unitTest->expected_output eq "";

# test against regular expression
$success = $unitTest->test_regex($service_output);
print "Regex matched successfully!\n" if $success or $unitTest->regex eq "";
print "Regex didn't match!\n" unless $success or $unitTest->regex eq "";

# test against xpath expression
$success = $unitTest->test_xpath($service_output);
print "XPATH matched successfully!\n" if $success or $unitTest->xpath eq "";
print "XPATH didn't match!\n" unless $success or $unitTest->xpath eq "";

sub doCall {
	my ( $name, $url, $input ) = @_;
	my $out;

	my $soap =
	  SOAP::Lite->uri("http://biomoby.org/")->proxy( $url, timeout => 20 )
	  ->on_fault(
		sub {
			my $soap = shift;
			my $res  = shift;

			my $msg =
			  ref $res
			  ? "--- SOAP FAULT ---\n"
			  . $res->faultcode . " "
			  . $res->faultstring
			  . "--- SOAP FAULT ---\n"
			  : "--- TRANSPORT ERROR ---\n"
			  . $soap->transport->status
			  . "\n$res\n"
			  . "--- TRANSPORT ERROR ---\n";

			die $msg;
		}
	  );
       # call the soap service
	$out = $soap->$name( SOAP::Data->type( "string" => "$input" ) )->result;

       # return the output
	return $out;
}