Keep logic within tests for as long as you can
Inspired by some recent podcast guests, I've started writing the first code for a Drupal-based SaaS product that I've been thinking of creating.
Here's an early iteration of the first test I wrote:
public function test_it_creates_a_project_node_from_json(): void {
self::assertNull(Node::load(id: 1));
$this->installEntitySchema(entity_type_id: 'node');
$this->installConfig(modules: self::$modules);
$projectData = json_decode(json: self::$projectJson, associative: TRUE);
self::assertNotNull($projectData);
Node::create([
'title' => $projectData['list'][0]['title'],
'type' => 'drupal_project',
])->save();
$node = Node::load(id: 1);
self::assertNotNull($node);
self::assertInstanceOf(actual: $node, expected: NodeInterface::class);
self::assertSame(actual: $node->label(), expected: 'Override Node Options');
self::assertSame(
actual: $node->get('field_drupalorg_node_id')->getString(),
expected: strval(107871),
);
}
It checks that, given some defined JSON data, it will create a node in my database.
It confirms no node ID exists when starting, runs some setup setups (this is a Kernel test), decodes the JSON, creates the node and asserts it contains the expected values.
There are two things that you may be wondering...
- Why do you have test setup code that you'll need within the test? Won't you need that for every test?
- Why are you creating the node within the test and not somewhere else?
The answer to both is that this is the first test, and I want to write as little code as possible for it to pass.
When I write the second test, I'll either need to duplicate the setup lines or extract them to a setUp() method.
I'll also need to refactor the code that creates the node.
Once I've written the second test, to get it to pass, I refactored to use Repository, Builder and Action classes.
If there's a regression, the test I had will fail, and I could revert to the passing version before reattempting the refactor.
With test-driven development, I want to work in small and simple steps and get to green by making the smallest and easiest possible change.
When I have a test that forces me to refactor and adopt a more complex approach, I'll do it.
- Oliver
