POC for using a fixture contianer to lazily load "fixtures"

00_Context.php

<?php

class OrganisationContext implements Context
{
    /**
     * Fixture container is similar to a service container, but for class instances.
     */
    public function __construct(private FixtureContainer $fixture)
    {
    }

    #[Given('I have an organisation :name')]
    public function iHaveAnOrganisation(string $name): void
    {
        // register a _named_ fixture for this class
        // a _Builder_ must be registered for the class and the parameters
        // are passed to its __invoke method
        $this->fixture->register(Organisation::class, $name, [
            'name' => $name
        ]);
    }

    #[Given('I have a project :project in organisation :organisation')]
    public function iHaveAProject(string $project, string $organisation): void
    {
        // the Builders also get the FixtureContainer so can retrieve dependencies
        // (in this case the organisation by the name we previously registered)
        $this->fixture->register(Project::class, $project, [
            'name' => $project,
            'organisation' => $organisation
        ]);
    }

    #[When('I upload an artifact to project :name')]
    public function iUploadAnArtifactToThatProject(string $project): void
    {
        // calling `get` will lazily invoke the Builders
        $project = $this->fixture->get(Project::class, $project);
    }
}

10_Builder.php

<?php

/**
 * Builder classes are registed in the "FixtureContainer" and provide fixtures
 * based on the `__invoke` return type (not sure if that's a great idea).
 */
final class ProjectBuilder
{
    public function __invoke(
        FixtureContainer $container,
        string $name,
        string $organisation
    ): Project
    {
        return new Project(
            Uuid::v4(),
            // _get_ (or create) the organisation instance
            $container->get(Organisation::class, $organisation),
            $name
        );
    }
}

20_FixtureContainer.php

<?php

final class FixtureContainer
{
    /**
     * @var array<string,array<string,\Closure():object>>
     */
    private array $factories = [];

    /**
     * @var array<string,array<string,object>>
     */
    private array $instances = [];

    /**
     * @param list<object> $builders
     */
    public function __construct(
        private array $builders
    )
    {
    }

    /**
     * @template TClass of object
     * @param class-string<TClass> $className
     * @return TClass
     */
    public function get(string $className, string $identifier): object
    {
        // blah...
        return $instance;
    }

    /**
     * @param class-string $className
     * @param array<string,mixed> $params
     */
    public function register(string $className, string $identifier, array $params = []): void
    {
        // blah...
    }
}