Adapter Pattern Generator

Creates Adapter pattern infrastructure for converting incompatible interfaces into expected ones.

When to Use

Scenario	Example
Legacy code integration	Wrap old API with new interface
Third-party library wrapping	Stripe SDK, AWS SDK adapters
Interface standardization	Multiple payment gateways with unified interface
Backward compatibility	Support old and new interfaces

Component Characteristics

Target Interface

• Defines expected operations
• Client code depends on this
• Domain layer contract

Adapter

• Implements target interface
• Wraps adaptee (existing class)
• Translates calls between interfaces

Adaptee

• Existing incompatible class
• Legacy code or external library
• Not modified by adapter

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Generation Process

Step 1: Generate Target Interface

Path: src/Domain/{BoundedContext}/

1. {Name}Interface.php — Expected interface contract

Step 2: Generate Adapter

Path: src/Infrastructure/{BoundedContext}/Adapter/

1. {Provider}{Name}Adapter.php — Converts adaptee to target interface
2. {Legacy}{Name}Adapter.php — Wraps legacy code
3. {External}{Name}Adapter.php — Wraps third-party library

Step 3: Generate Tests

1. {AdapterName}Test.php — Adapter behavior verification

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File Placement

Component	Path
Target Interface	src/Domain/{BoundedContext}/
Adapter	src/Infrastructure/{BoundedContext}/Adapter/
Adaptee (existing)	External library or legacy code
Unit Tests	tests/Unit/Infrastructure/{BoundedContext}/Adapter/

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Naming Conventions

Component	Pattern	Example
Target Interface	{Name}Interface	PaymentGatewayInterface
Adapter	{Provider}{Name}Adapter	StripePaymentGatewayAdapter
Test	{ClassName}Test	StripePaymentGatewayAdapterTest

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Quick Template Reference

Target Interface

interface {Name}Interface
{
    public function {operation}({params}): {returnType};
}

Adapter

final readonly class {Provider}{Name}Adapter implements {Name}Interface
{
    public function __construct(
        private {Adaptee} $adaptee
    ) {}

    public function {operation}({params}): {returnType}
    {
        // Translate params to adaptee format
        $adapteeResult = $this->adaptee->{adapteeMethod}({adapteeParams});

        // Convert result to target format
        return {convertedResult};
    }
}

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Usage Example

// Stripe SDK is the adaptee
$stripeClient = new \Stripe\StripeClient($apiKey);

// Adapter makes it compatible with our interface
$paymentGateway = new StripePaymentGatewayAdapter($stripeClient);

// Use through our domain interface
$result = $paymentGateway->charge($amount, $token);

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Common Adapters

Adapter	Purpose
PaymentGatewayAdapter	Wrap Stripe, PayPal, Square APIs
StorageAdapter	Wrap AWS S3, Google Cloud Storage
MessengerAdapter	Wrap Slack, Discord, Telegram APIs
EmailAdapter	Wrap SendGrid, Mailgun, AWS SES
CacheAdapter	Wrap Redis, Memcached, APCu
LoggerAdapter	Wrap Monolog, Syslog, custom loggers

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Anti-patterns to Avoid

Anti-pattern	Problem	Solution
Leaky Adapter	Exposing adaptee details	Return only target interface types
Multiple Responsibilities	Adapter doing business logic	Keep adapters focused on translation
Tight Coupling	Adapter depends on concrete adaptee	Accept interface when possible
Heavy Translation	Complex conversions in adapter	Extract translator services
Missing Error Handling	Adaptee exceptions leak	Catch and convert to domain exceptions

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References

For complete PHP templates and examples, see:

• references/templates.md — Target Interface, Adapter templates for payment, storage, messaging
• references/examples.md — Stripe, PayPal, AWS S3, legacy user adapters with unit tests