add-bc-contract

name	add-bc-contract
description	Add Contract for inter-BC communication using Provider pattern. Use when one Bounded Context needs to access data from another BC (e.g., Inventory needs Articles from Admin). Creates Contract interface, Provider implementation, and configuration.

Add BC Contract

Create Contract for inter-BC communication using Provider pattern.

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When to Use

• BC needs to read data from another BC
• Creating select options from another BC (TwigComponent)
• Exposing domain data to other contexts

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Inputs/Outputs

Input	Example	Output
provider_bc	Admin	ProviderBC/Contracts/ContractName.php
consumer_bc	Inventory	ProviderBC/Adapters/Contracts/ProviderBCContractName.php
contract_name	ArticleProvider	ProviderBC/Frameworks/config/services.yaml (updated)
methods	['provide', 'provideAll']	ConsumerBC/Frameworks/deptrac.yaml (updated)

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Process

Step	File	Action
Contract	ProviderBC/Contracts/ContractName.php	Interface with methods (template: contract.php.tpl)
Provider	ProviderBC/Adapters/Contracts/ProviderBCContractName.php	Implementation with Finder (template: provider.php.tpl)
Config	ProviderBC/Frameworks/config/services.yaml	Autowire Contract → Provider
Deptrac	ConsumerBC/Frameworks/deptrac.yaml	Allow ProviderBC\Contracts
Validate	-	make cs-fixer && make stan && bin/deptrac analyse && make qa

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Structures

Contract (interface in ProviderBC/Contracts/):

interface ContractName {
    public function provide(string $uuid): EntityData; // throws
    public function provideAll(?array $ids = null): iterable;
}

Provider (readonly, uses Finder):

final readonly class ProviderBCContractName implements ContractName {
    public function __construct(private EntityFinder $finder) {} // Finder, NOT Repository

    public function provide(string $uuid): EntityData {
        $entity = $this->finder->find($uuid) ?? throw EntityNotFound::fromUuid($uuid);
        return $this->toData($entity);
    }

    public function provideAll(?array $ids = null): iterable {
        $entities = $ids ? $this->finder->findByUuids($ids) : $this->finder->findAll();
        foreach ($entities as ) {
             ->();
        }
    }

     {  }
}

Config (ProviderBC/Frameworks/config/services.yaml):

ProviderBC\Contracts\ContractName:
    class: ProviderBC\Adapters\Contracts\ProviderBCContractName

Deptrac (ConsumerBC/Frameworks/deptrac.yaml):

ConsumerBC\Adapters:
    - ProviderBC\Contracts  # ONLY Contracts, NOT Entities/UseCases

See: docs/GLOSSARY.md#contract, #provider, #data-dto

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Rules

CRITICAL:

• Provider uses Finder (NOT Repository) - providers are read-only
• Consumer depends ONLY on Contract interface (never Provider implementation)
• Deptrac allows ONLY Contracts namespace (not Entities/UseCases)

Locations:

• Contract: ProviderBC/Contracts/
• Provider: ProviderBC/Adapters/Contracts/
• Exception: ProviderBC/Contracts/Exception/ if needed
• DTO: ProviderBC/Contracts/DTO/ if complex data

Naming:

• Contract: {Entity}Provider (e.g., ArticleProvider)
• Provider: {BC}{Contract} (e.g., AdminArticleProvider)

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Variants

Query Provider (data access):

public function provide(string $uuid): EntityData;
public function provideAll(?array $ids = null): iterable;

TwigComponent Provider (form select):

/** @return array<string, string> [uuid => label] */
public function getAllForChoice(): array;

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Templates

• contract.php.tpl - Contract interface
• provider.php.tpl - Provider implementation

Location: .claude/templates/

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References

• Contract/Provider pattern: docs/GLOSSARY.md#contract, #provider
• Inter-BC architecture: docs/architecture.md#inter-bc
• Detailed guide: docs/guides/bounded-contexts.md