http://www.perlmonks.org?node_id=1177236

yulivee07 has asked for the wisdom of the Perl Monks concerning the following question:

Hello fellow Perl-Monks,

I am expanding my knowledge in testing right now. I want to test some functions of mine which interact with an LDAP-Server.

This might sound like a stupid question, but what is the best way to deal with Wrapper-Classes?

Context:
I write a module, which gets some Users from LDAP.
To communicate with the LDAP, I use a provided module from my workplace which wraps some system-specific parameters in the LDAP-methods (Utils::Ldap::CompanyLdap) and provides some additional methods.
This module again is a subclass of another LDAP-Wrapper Module (Utils::Ldap::Base) which finally uses Net::LDAP.

Now, in my program I use the first Ldap-Module e.g.
package MyAwesomeProgram; use Utils::Ldap::CompanyLdap; sub read_users { # code that reads users from Ldap # searchGetEntries/get_value is provided by Utils::Ldap::CompanyLda +p foreach my $entry ( $ldap->searchGetEntries() ) { my $uid = $entry->get_value( 'uid' ); #... do something more } } 1;
I want to test the read_users function of my program, which gets its users via Utils::Ldap::CompanyLdap. How do I mock this? As you see, I do not directly interact with a Net::LDAP-Object

I have already understood that there is Test::Net::LDAP::Mock/Test::Net::LDAP::Utils qw(ldap_mockify) which can mock an Ldap Connection. What I do not understand yet: How can I use this in conjunction with my Wrapper Module? My module uses the code and the functions of our Ldap-Wrappers. Would the correct way be to write mocking code for the wrappers (e.g. Utils::Ldap::CompanyLdap::Mock), or is there a way of overwriting the Net::LDAP Object which is used by the Base-Wrapper Class Utils::Ldap::Base? I am not shure how to best approach this.

Second Question:
In case I get this working, is there a way of taking a Net::LDAP object and feeding it into my Mock-Object? I'd like to copy the datastructe of our LDAP to the Mock-Object.

Kind regards,

yulivee

Replies are listed 'Best First'.
Re: Testing Wrapped LDAP Classes
by stevieb (Canon) on Dec 05, 2016 at 15:56 UTC

    There are a few mocking distributions on the CPAN, but I'll show an example using my Mock::Sub. You can mock out subs, then tell it to do something (side_effect()), or return something (return_value()). Instead of using a method to set them, you can also specify them in the constructor if you choose (then remove/modify them with the methods later):

    use warnings; use strict; use lib '.'; use Mock::Sub; use Test::More; use Utils::Ldap::CompanyLdap; my $m = Mock::Sub->new; my $ldap = Utils::Ldap::CompanyLdap->new; my $mocked_sub = $m->mock( 'Utils::Ldap::CompanyLdap::searchGetEntries' ); $mocked_sub->return_value(qw(steve mike dave)); read_users(); is $mocked_sub->called, 1, "searchGetEntries() called ok"; sub read_users { for my $entry ($ldap->searchGetEntries()){ print "$entry\n"; } } done_testing();

    Output:

    steve mike dave ok 1 - searchGetEntries() called ok 1..1
      Update:
      The Ldap Object looks like this before the searchUser (some details obfuscated):
      $VAR1 = bless( { 'OPT' => { 'base' => somebase, 'idprefix' => 'cn', 'userid' => 'admin', 'charset' => 'ISO-8859-15', 'bindretry' => '3', 'ldaps' => 1, 'timeout' => '60', 'server' => someip, 'waitretry' => '5', } }, 'Utils::Ldap::CompanyLdap' );

      And it looks like that after the searchUser:
      bless( { 's_result' => bless( { 'parent' => bless( { 'net_ldap_version' => '3', 'net_ldap_scheme' => 'ldaps', 'net_ldap_debug' => 0, 'net_ldap_onerror' => sub { "DUMMY" }, 'net_ldap_host' => someip, 'net_ldap_uri' => someip, 'net_ldap_resp' => {}, 'net_ldap_async' => 0, 'net_ldap_port' => 636, 'net_ldap_refcnt' => 0 }, 'Net::LDAPS' ), 'entries' => [ bless( { + + 'changes' => [], 'changetype' => 'modify', 'asn' => { 'objectName' => 'uid=bla,ou=People,ou=foo,dc=bar +,dc=baz,dc=com', 'attributes' => [ {'type' => 'uid', 'vals' => [ someuid ] }, {'type' => 'cnum', 'vals' => [ 'L07345897' ] + }, {'type' => 'freeze','vals' => [ 'false' ] }, {'type' => 'dn', 'vals' => ['uid=bla,c=us, +ou=otherldap,o=baz.com' ] }, {'type' => 'email', 'vals' => [ a@b.com'] }, ] } }, 'Net::LDAP::Entry' ), ], 'errorMessage' => '', 'ctrl_hash' => undef, 'resultCode' => 0, 'callback' => undef, 'matchedDN' => '', 'mesgid' => 2, 'controls' => undef, 'raw' => undef }, 'Net::LDAP::Search' ), 'BIND' => 0, 'errors' => '', 'error' => '', 'OPT' => { 'base' => somebase, 'idprefix' => 'cn', 'userid' => 'admin', 'charset' => 'ISO-8859-15', 'bindretry' => 3, 'ldaps' => 1, 'timeout' => '60', 'server' => someip, 'waitretry' => '5', }, }, 'Utils::Ldap::CompanyLdap' );
      The 'entries' contain all the userids, I have just added one to demonstrate. Normally there would be more.
      Hi stevieb, thanks for your answer! This looks really good and I tried to integrate this into my code. Yet I still have problems...

      I have a subroutine in my program called like this:
      sub search_ldap { + + my ( $self, $ldap ) = @_; # get uid, email, ecufreeze, cnum, itimaccess from LDAP report LOG_INFO, "Reading from Ldap"; unless ( $ldap->searchUser( filter => '(uid=*)', attributes => "freeze uid dn cnum emai +l" ) ) { report LOG_ERROR, "Can not list user from LDAP: " . $ldap->get +Error(); exit 0; } return $ldap; }
      In this case $ldap is a Utils::Ldap::CompanyLdap object. when calling $ldap->searchUser this object writes the users into itself. So with the searchUser call, the object itself is altered.

      What I tried:
      my $m = Mock::Sub->new; my $ldap = Utils::Ldap::CompanyLdap->new; + + + my $mocked_sub = $m->mock( 'Utils::Ldap::CompanyLdap::searchUser' ); # This is actually a Utils::Ldap::CompanyLdap-Object I copied via Data +::Dumper my $return_value = bless ( ... ); $mocked_sub->return_value($return_value); # cache is an instance of my own object + ok( $cache->search_ldap($my_ldap) ); ok( $cache->read_all_userids($my_ldap) ); is $mocked_sub->called, 1, "searchUser() called ok";
      I was hoping that be putting the object the way I want it to into my return value, the solution would work. The thing is, I noticed searchUser doesn't really return anything, it only appends to the object-instance. So Mock::Sub returns the right thing, but the code continues to work with the old ldap-object. Any Ideas how to solve this?

      Greetings and thanks for your insights so far,
      yulivee

        This is what the side_effect() functionality does... allows you to do stuff (eg: modify an object) when there's no need for a return. Here's an example:

        use warnings; use strict; package Thing; { sub new { return bless {}, shift; } sub modify { my ($self) = @_; $self->{modified} = 'modified by original sub'; } } package main; use Data::Dumper; use Mock::Sub; use Test::More; my $m = Mock::Sub->new; my $thing = Thing->new; my $modify_sub = $m->mock('Thing::modify'); $modify_sub->side_effect( sub { my $obj = shift; $obj->{modified} = 'modified by mocked sub'; } ); print "before mocked sub called...\n\n"; print Dumper $thing; $thing->modify; print "\n\nafter mocked sub called...\n\n"; print Dumper $thing; print "\n\n"; is defined $thing->{modified}, 1, "obj was modified ok"; like $thing->{modified}, qr/mocked sub/, "obj was changed by mock"; is $modify_sub->called, 1, "mocked sub called ok"; done_testing();

        Output:

        before mocked sub called... $VAR1 = bless( {}, 'Thing' ); after mocked sub called... $VAR1 = bless( { 'modified' => 'modified by mocked sub' }, 'Thing' ); ok 1 - obj was modified ok ok 2 - obj was changed by mock ok 3 - mocked sub called ok 1..3

        So, there's no return anymore. The side_effect() code reference will get all parameters passed in as they were sent in to the real sub call (in this case, $self, as it's the only param on the method call. We then have the side effect add a new hash key to itself and assign it a value. After side effect is complete, the main object is updated just like the original function would have done, without having to call the real function.