Can't mock implementations of abstract methods required by a Moose role

[DrHyde]

If you have a Moose class which consumes a role, and that role in turn requires that the class implement a method foo then you can't use Test::MockModule to over-ride the class's implementation. Attempting to do so can result in errors like:

"Invalid implementation class MyApp::SomeClass: 'MyApp::SomeRole' requires the method 'foo' to be implemented by 'Moose::Meta::Class::ANON::SERIAL::8'. If you imported functions intending to use them as methods, you need to explicitly mark them as such, via Moose::Meta::Class::ANON::SERIAL::8->meta->add_method(foo => ..."

As a work-around, instead of doing this in my tests:

my $mockery = Test::MockModule->new('MyApp::Class');
$mockery->mock( foo => sub { 0 });

I am doing this:

MyApp::Class->meta->add_method(totes_not_a_real_sub => sub { 0 });
my $mockery = Test::MockModule->new('MyApp::Class');
$mockery->mock( foo => \&MyApp::Class::totes_not_a_real_sub);

but obviously I'd prefer to have Test::MockModule do the nasty Moose dance for me automagically. Would you accept a patch for that?

[geofffranks]

Sure!

…

Sent from my iPhone

On Mar 12, 2021, at 10:11 AM, David Cantrell ***@***.***> wrote:  If you have a Moose class which consumes a role, and that role in turn requires that the class implement a method foo then you can't use Test::MockModule to over-ride the class's implementation. Attempting to do so can result in errors like: "Invalid implementation class MyApp::SomeClass: 'MyApp::SomeRole' requires the method 'foo' to be implemented by 'Moose::Meta::Class::ANON::SERIAL::8'. If you imported functions intending to use them as methods, you need to explicitly mark them as such, via Moose::Meta::Class::ANON::SERIAL::8->meta->add_method(foo => ..." As a work-around, instead of doing this in my tests: my $mockery = Test::MockModule->new('MyApp::Class'); $mockery->mock( foo => sub { 0 }); I am doing this: MyApp::Class->meta->add_method(totes_not_a_real_sub => sub { 0 }); my $mockery = Test::MockModule->new('MyApp::Class'); $mockery->mock( foo => \&MyApp::Class::totes_not_a_real_sub); but obviously I'd prefer to have Test::MockModule do the nasty Moose dance for me automagically. Would you accept a patch for that? — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub, or unsubscribe.

[DrHyde]

FYI I'm having trouble coming up with a small test case without pulling in much of my app's code. There's definitely a problem, but it's unlikely to affect many people.

[DrHyde]

Note to self, copied from IRC:

09:10 <@.......> including an amusing: package A { sub foo {} } ; package B extends A { around 'foo' => sub {} 
                 }; then use Test::MockModule to mock A::foo, and Class::Load::load_class B - which fails when 
                 it hits the around because it can't find A::foo :D
09:15 < DrHyde> hmmm, i wonder if that's at the root of https://github.com/geofffranks/test-mockmodule/issues/55

[fleetfootmike]

the above is me, if you want a test case to reproduce...

[DrHyde]

Yes please @fleetfootmike!

[fleetfootmike]

t/mockmodule_around.t

use Test::More tests => 1;
use Test::Exception;
use Test::MockModule;
use Class::Load qw/load_class/;

my $mock = Test::MockModule->new('TestA'); # replace with TestB and it passes
$mock->mock( foo => sub { 3; } );

lives_ok { load_class('TestB'); } "This shouldn't die";

TestA.pm

package TestA;
use Moose;
sub foo { 1; }
1;

TestB.pm

package TestB;
use Moose;
extends 'TestA';
around foo => sub { 2; };
1;

#   Failed test 'This shouldn't die'
#   at t/mockmodule_around.t line 9.
# died: The method 'foo' was not found in the inheritance hierarchy for TestB at /usr/local/lib/perl5/site_perl/5.14.2/x86_64-linux/Class/MOP/Class.pm line 1053.

[XSven]

... # replace with TestB and it passes

will mock the "around"ed foo in TestB and no longer the foo that belongs to TestA. The same happens if you hinder Test::MockModule to pre-load TestA.

my $mock = Test::MockModule->new('TestA', no_auto => 1);

t/mockmodule_around.t passes.

[XSven]

Slight correction:

If no_auto is turned on to make the test pass a redefine warning is raised:

prove -v mockmodule_around.t
mockmodule_around.t ..
1..1
Subroutine foo redefined at TestA.pm line 3.
ok 1 - This shouldn't die
ok
All tests successful.
Files=1, Tests=1,  0 wallclock secs ( 0.01 usr  0.01 sys +  0.07 cusr  0.00 csys =  0.09 CPU)
Result: PASS