Dynamic Config Values for Each PHPUnit Test Case in Laravel

#phpunit #laravel #tdd #php

This was originally posted on my blog

Problem:

I am currently working on a USSD application that supports switching between different gateway providers at runtime by changing a configuration value.

Testing each provider test case was simple and straight forward. I would update the value in my phpunit.xml file and off I go. However, I ran into problems when I wanted to run my entire test suite.

Solution:

It turns out the solution is quite a simple one: Facades. Laravel allows one to mock any Facade when writing your tests. The documentation however, discourages from mocking the Config facade. Instead one should use the Config::set method.

So, I did something along the lines of the code below.

<?php
// define your namespace and dependencies here

use Illuminate\Support\Facades\Config;

class GatewayProviderOneTest extends TestCase
{
    public function setUp ()
    {
        parent::setUp();
        Config::set("defaultGatewayProvider", "firstProvider");
    }

    // ... your test methods come here
}

That’s all I needed. Now GatewayProviderOneTest will run its assertions against the value set as the defaultGatewayProvider: firstProvider.

Additionally, you can revert this to a default value every time in your tearDown method. I however didn’t need to do this.

Top comments (8)

Marvin Espira • Dec 3 '20

I'm curious to know how you implemented your USSD

David Lartey • Dec 13 '20

Hi Marvin,

USSD use to also sound complex for me but after a while, I noticed it was just APIs. So if you can build APIs, you can build a USSD application.

If you're just getting started I built a Laravel (Package) to make it really to build USSD applications. You can find it here: github.com/dbilovd/php-ussd.

It was actually when I was building this package that I learnt the issue I wrote about in the post.

If you need any help, do let me know.
Thanks