Refactoring for Efficiency: Sharing Tenant Setup Logic in Our Testing Suite

In large projects, repetitive code across numerous tests can lead to maintenance overhead and inconsistencies. We recently tackled this in our application by extracting common tenant setup logic into a reusable trait, significantly reducing code duplication and improving test maintainability.

The Problem: Duplicated Boilerplate

Our testing suite involved numerous tests that required setting up a tenant schema. This setup typically involved dropping and creating the schema, running migrations, creating a user, and acting as that user. This process was duplicated across a large number of test files, leading to:

• Code bloat: Each test file contained the same ~25 lines of setup code.
• Maintenance burden: Any changes to the tenant setup process required modifying multiple files.
• Inconsistency: Subtle variations in the setup process could lead to inconsistent test behavior.

The Solution: Introducing the InteractsWithTenantSchema Trait

To address this, we introduced a trait called InteractsWithTenantSchema. This trait encapsulates the common tenant setup logic into a single, reusable component. The trait provides a method, createTenantWithSchema(), which performs the necessary steps to set up the tenant schema.

Here's an example of how the trait can be used in a test:

<?php

namespace Tests\Feature;

use Illuminate\Foundation\Testing\RefreshDatabase;
use Tests\TestCase;
use App\Traits\InteractsWithTenantSchema;

class ExampleTest extends TestCase
{
    use RefreshDatabase, InteractsWithTenantSchema;

    public function test_example(): void
    {
        $tenant = $this->createTenantWithSchema('example_tenant');

        // Your test logic here, interacting with the tenant schema
        $this->assertTrue(true); // Example assertion
    }
}

Addressing Initial Refactor Issues

The initial automated refactor introduced a few issues that needed to be addressed:

• Missing RefreshDatabase: The RefreshDatabase trait and $seed=true property were inadvertently removed from the base TestCase class. This was restored to ensure tests run in a clean database state.
• Incorrect User Context: Some tests, like CacheShowcaseProfilesCommandTest, relied on a specific user. The trait was updated to ensure the correct user context was used.
• Seeded Email Conflicts: Conflicts arose in SeedPosts tests due to duplicate email addresses. This was handled by ensuring unique email addresses are used when seeding data.

Benefits of Using the Trait

Using the InteractsWithTenantSchema trait provides several benefits:

• Reduced code duplication: Eliminates the need to repeat the same setup code in multiple test files.
• Improved maintainability: Changes to the tenant setup process only need to be made in one place.
• Increased consistency: Ensures that all tests use the same tenant setup process.
• Enhanced readability: Test files are cleaner and easier to understand, focusing on the specific test logic rather than the setup details.

Key Takeaways

• Identify and extract common boilerplate code into reusable components like traits or helper functions.
• Pay close attention to potential issues during refactoring, such as missing dependencies or incorrect context.
• Thoroughly test your refactored code to ensure it behaves as expected.
• Strive for DRY (Don't Repeat Yourself) principles to improve code maintainability and reduce errors.

By extracting the tenant setup logic into a reusable trait, we significantly reduced code duplication, improved maintainability, and increased consistency in our testing suite. This approach can be applied to other areas of your codebase to improve its overall quality and maintainability.