Mock Repository Generator

Generates InMemory (Fake) repository implementations for testing.

Characteristics

• •No database — stores entities in memory
• •Fast — no I/O operations
• •Isolated — fresh state per test
• •Deterministic — predictable behavior
• •Implements interface — same contract as real repository

Template

<?php

declare(strict_types=1);

namespace Tests\Fake;

use {RepositoryInterface};
use {Entity};
use {EntityId};

final class InMemory{Entity}Repository implements {RepositoryInterface}
{
    /** @var array<string, {Entity}> */
    private array $entities = [];

    public function save({Entity} $entity): void
    {
        $this->entities[$entity->id()->toString()] = $entity;
    }

    public function findById({EntityId} $id): ?{Entity}
    {
        return $this->entities[$id->toString()] ?? null;
    }

    public function delete({Entity} $entity): void
    {
        unset($this->entities[$entity->id()->toString()]);
    }

    /** @return list<{Entity}> */
    public function findAll(): array
    {
        return array_values($this->entities);
    }

    public function clear(): void
    {
        $this->entities = [];
    }
}

Generation Instructions

1. •

   Read the repository interface:

   • •Extract all method signatures
   • •Identify entity type
   • •Identify ID type
2. •

   Generate InMemory implementation:

   • •Array storage keyed by ID
   • •Implement all interface methods
   • •Add clear() for test cleanup
3. •

   Handle complex queries:

   • •Use array_filter for criteria
   • •Support specifications if used
   • •Implement pagination with array_slice
4. •

   Add test helpers (optional):

   • •getAll() — access internal state
   • •has(Id $id) — check existence
   • •count() — entity count
5. •

   File placement:

   • •tests/Fake/InMemory{Entity}Repository.php
   • •Or tests/Double/ directory

Best Practices

1. •Match interface exactly — same method signatures
2. •Isolate per test — use clear() in tearDown
3. •Avoid complexity — simple in-memory logic
4. •Document deviations — if behavior differs from real impl
5. •Consider thread safety — for parallel tests (usually not needed)

References

• •references/examples.md — Complete repository examples (User, Order, Product)
• •references/other-fakes.md — EventDispatcher, Mailer, Clock fakes