How to Instantly Migrate PhpSpec to PHPUnit

2019-03-21

"Nobody believes in anything without an inner feeling that it can be realized.
This is the only source of dreamlike powers."

Disclaimer: I never saw PhpSpec code before this mentoring session. All I learned was from my client and their needs (and bit of reading the documentation).

"Why do you Have 2 Unit-Testing Frameworks?"

That was my question to one of my clients when I saw both PhpSpec and PHPUnit tests in its code base.

• "So what is added value of PhpSpec over PHPUnit?"
• "Well, I use it for unit testing."
• "How is that different to PHPUnit?"
• "It tests the behavior."
• "Well, what is the difference between assertSame() and shouldBeEqualTo()"?
• "None really."

But before I noticed PhpSpec and asked about it, we had another chat:

• "Why there is this static class when the rest of your code uses Symfony Dependency Injection?"
• "It's needed for my test."
• "Why don't you use KernelTestCase"?
• "I can't."
• "Well, you have Symfony and you run your whole application on it, you have PHPUnit, so you can. Why not?"
• "It's not PHPUnit, it's PhpSpec."
• "So?"
• "It doesn't use any container, there must be static in my code."
• "So what is added value of PhpSpec over PHPUnit?"
• "..."

Then I explored PhpSpec and found out, it's basically PHPUnit with different naming.

"It looks like Y, a variant of X, could be done in
about half the time, and you lose only one feature."

Trends over Long-Tail Effect

Why did we choose to migrate PhpSpec tests to PHPUnit? Well, it's better obviously... Do you agree with me just because I wrote that? Don't do that, it's my personal opinionated opinion (= feeling, emotion). Ask me for some data instead.

Let's look at downloads:

• 1 mil. downloads
• 14 mils. downloads
• 117 mils. downloads

But 117 mil. downloads can be like "You should use Windows XP because it's the most used Windows version ever!" That's classic manipulation of dying dinosaur.

Let's see the trends! In the same order:

Which one would you pick from this 2 information? I'd go for the last one, so did my client. So that's why we agreed to migrate PhpSpec (the middle one) to PHPUnit.

This is how 1 spec migration might look like:

-namespace spec\App\Product;
+namespace Tests\App\Product;

-use PhpSpec\ObjectBehavior;

-final class CategorySpec extends ObjectBehavior
+final class CategoryTest extends \PHPUnit\Framework\TestCase
 {
+    /**
+     * @var \App\Product\Category
+     */
+    private $createMe;

-    public function let()
+    protected function setUp(): void
     {
-        $this->beConstructedWith(5);
+        $this->createMe = new \App\Product\Category(5);
     }

-    public function it_returns_id()
+    public function testReturnsId()
     {
-        $this->id()->shouldReturn(5);
+        $this->assertSame(5, $this->createMe->id());
     }

-    public function it_blows()
+    public function testBlows()
     {
-        $this->shouldThrow('SomeException')->during('item', [5]);
+        $this->expectException('SomeException');
+        $this->createMe->item(5);
     }
 }

Pretty clear, right?

How to Instantly Migrate from PhpSpec to PHPUnit?

First, take a 2-week paid vacation... Just kidding. Start with Rector which migrates ~95 % of code cases. It also renames *Spec.php to *Test.php and moves them from /spec to /tests directory:

1. Add Rector

composer require rector/rector --dev

2. Create rector.php config

use Rector\Set\ValueObject\SetList;
use Rector\Config\RectorConfig;

return function (RectorConfig $rectorConfig): void {
    $rectorConfig->import(SetList::PHPSPEC_TO_PHPUNIT);
};

3. Run Rector on your tests directories

vendor/bin/rector process tests

Take couple of minutes to polish the rest of code and send PR to your project ✅

And what was the 2nd testing framework that Rector migrated? Nette\Tester.

Happy coding!