Replace Peridot/Leo/WP_Mock tests with Kahlan

[mallorydxw]

Per discussion on ticket #21 Rob and I agreed that replacing
Peridot/Leo/WP_Mock with Kahlan would be the best way to allow us to
update dependencies and allow installing the latest version of Psalm.

Remove peridot dependencies and config file:

• rm peridot.php
• composer remove --dev peridot-php/peridot peridot-php/leo peridot-php/peridot-dot-reporter 10up/wp_mock
• GitHub Actions: Remove peridot test

Add Kahlan dependencies and config file:

• composer require --dev kahlan/kahlan
• Add kahlan-config.php
• GitHub Actions: Add kahlan test

Leo-to-Kahlan changes:

• s/->to->be->an->instanceof/toBeAnInstanceOf/
• s/to->equal/toEqual/
• s/to->contain/toContain/
• s/to->be->empty/toBeEmpty/
• s/to->be->equal/toEqual/

WP_Mock-to-Kahlan changes:

• Remove all WP_Mock::setUp and WP_Mock::tearDown
• Convert WP_Mock::expectActionAdded to expect()
• Convert WP_Mock::wpFunction to allow()/expect()

Miscellaneous changes:

• Use namespaces in test files
• composer update

Link: #21

[RobjS]

This all looks good to me 👍

There is one opportunity to tighten up the tests of register() methods if we like (and would fix something that always bugged me about WP_Mock and the looseness of expectActionAdded()).

Currently, the following would pass:

public function register()
    {
        add_action('wp_footer', [$this, 'wpFooter']);
        add_action('wp_footerx', [$this, 'wpFooter']);
    }

Tested by:

describe('->register()', function () {
        it('registers actions', function () {
            allow('add_action')->toBeCalled();
            expect('add_action')->toBeCalled()->once()->with('wp_footer', [$this->analytics, 'wpFooter']);
            $this->analytics->register();
        });
    });

However, this test wouldn't pass:

describe('->register()', function () {
        it('registers actions', function () {
            allow('add_action')->toBeCalled();
            expect('add_action')->toBeCalled()->once();
            expect('add_action')->toBeCalled()->with('wp_footer', [$this->analytics, 'wpFooter']);
            $this->analytics->register();
        });
    });

The difference between the effect of those two register() methods could be quite profound, so I feel like that could be a change worth making; what do you think?

[mallorydxw]

@RobjS Thank you. I didn't notice that that's how Kahlan's allow()/expect() worked.

[RobjS]

@mallorydxw I only worked it out by trial and error, the documentation doesn't really make it clear!

I guess it makes sense in that you wouldn't normally care about the exact number of times global functions were being called with exactly what arguments when unit testing, only that the tested method's output was as expected. But in the case of register() functions, all we care about is the calls to the global functions.